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Posts Tagged ‘Full genome sequencing’

Author & Curator: Aviva Lev-Ari, PhD, RN

Article ID #16: Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine – Part 1. Published on 1/13/2013

WordCloud Image Produced by Adam Tubman

Cancer Diagnostics by Genomic Sequencing: ‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

How to Tailor Cancer Therapy to the particular Genetics of a patient’s Cancer

THIS IS A SERIES OF FOUR POINTS OF VIEW IN SUPPORT OF the Paradigm Shift in Human Genomics

‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

PRESENTED in the following FOUR PARTS. Recommended to be read in its entirety for completeness and arrival to the End Point of Present and Future Frontier of Research in Genomics

Part 1:

Research Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine

Part 2:

LEADERS in the Competitive Space of Genome Sequencing of Genetic Mutations for Therapeutic Drug Selection in Cancer Personalized Treatment

http://pharmaceuticalintelligence.com/2013/01/13/leaders-in-genome-sequencing-of-genetic-mutations-for-therapeutic-drug-selection-in-cancer-personalized-treatment-part-2/

Part 3:

Personalized Medicine: An Institute Profile – Coriell Institute for Medical Research

http://pharmaceuticalintelligence.com/2013/01/13/personalized-medicine-an-institute-profile-coriell-institute-for-medical-research-part-3/

Part 4:

The Consumer Market for Personal DNA Sequencing

http://pharmaceuticalintelligence.com/2013/01/13/consumer-market-for-personal-dna-sequencing-part-4/

 

Part 1:

Research Paradigm Shift in Human Genomics – Predictive Biomarkers and Personalized Medicine

 

In Part 1, we will address the following FIVE DIRECTIONS in Genomics Research

  • ‘No’ to Sequencing Patient’s DNA, ‘No’ to Sequencing Patient’s Tumor, ‘Yes’ to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities
  • Sequencing DNA from individual cells vs “humans as a whole.” Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.
  • Promising Research Directions By Watson, 1/10/2013
  • Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper
  • Molecular Analysis of the different Stages of  Cancer Progression for Targeting Therapy

First:

Predictive Biomarkers and Personalized Medicine

No to Sequencing Patient’s DNA, No to Sequencing Patient’s Tumor, Yes to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities

 

MD Anderson Research

targeted agents matched with tumor molecular aberrations.

Molecular analysis

Patients whose tumors had an aberration were treated with matched targeted therapy, compared with those of consecutive patients who were not treated with matched targeted therapy

Results

40.2% – 1 or more aberration.

In 1 aberration , matched tx higher response rate  27% vs 5%

Longer time ot treatment failure  TTF 5.2 vs. 2.2

Longer survival  13.4 vs. 9 months

Pt. w/1 mutation (molecular aberrationMatched targeted therapy associated with longer TTF vs. prior systemic therapy 5.2 vs. 3.1

matched therapy was an independent factor predicting response superior to TTF

Conclusion

Not randomized study, and patients had diverse tumor types and a median of 5 prior therapies,  results suggest that identifying specific molecular abnormalities and choosing therapy based on these abnormalities is relevant in phase I clinical trials

Clin Cancer Res. 2012 Nov 15;18(22):6373-83. doi: 10.1158/1078-0432.CCR-12-1627. Epub 2012 Sep 10.

Personalized medicine in a phase I clinical trials program: the MD Anderson Cancer Center initiative.

Tsimberidou AM, Iskander NG, Hong DS, Wheler JJ, Falchook GS, Fu S, Piha-Paul S, Naing A, Janku F, Luthra R, Ye Y, Wen S, Berry D, Kurzrock R.

Source

Department of Investigational Cancer Therapeutics, Phase I Clinical Trials Program, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. atsimber@mdanderson.org

http://www.ncbi.nlm.nih.gov/pubmed?term=22966018

 

Opinion by Dr. Pierluigi Scalia, 1/11/2013.

The fact of using nanotechnology in order to target and treat abnormal cancer cells and tissues adds a powerful weapon towards eradicating the disease in the foreseeable future. However, focusing on weapons when we still have not found a reliable way to build that personalized “shooting target” (Cancer Fingerprinting) still constitutes, in my opinion, the single most relevant barrier to the adoption of Personalized treatments.

http://pharmaceuticalintelligence.com/2013/01/09/nanotechnology-personalized-medicine-and-dna-sequencing/

Ritu Saxena’s interview

http://pharmaceuticalintelligence.com/2013/01/07/personalized-medicine-gearing-up-to-tackle-cancer/

Other studies supporting this perspective

 

p53 gene deletion predicts for poor survival and non-response to therapy with purine analogs in chronic B-cell leukemias

 

Chromosome aberrations in solid tumors

 

Chromosome aberrations in B-cell chronic lymphocytic leukemia: reassessment based on molecular cytogenetic analysis

 

Multivariate analysis of prognostic factors in CLL: clinical stage, IGVH gene mutational status, and loss or mutation of the p53 gene are independent prognostic factors

 

Clonal analysis of delayed karyotypic abnormalities and gene mutations in radiation-induced genetic instability.

 

Comprehensive genetic characterization of CLL: a study on 506 cases analysed with chromosome banding analysis, interphase FISH, IgVH status and …

 

Detection of aberrations of the p53 alleles and the gene transcript in human tumor cell lines by single-strand conformation polymorphism analysis

 

Genetic aberrations detected by comparative genomic hybridization are associated with clinical outcome in renal cell carcinoma

 

VH mutation status, CD38 expression level, genomic aberrations, and survival in chronic lymphocytic leukemia

 

Microarray gene expression profiling of B-cell chronic lymphocytic leukemia subgroups defined by genomic aberrations and VH mutation status

 

… nucleophosmin (NPM1) predicts favorable prognosis in younger adults with acute myeloid leukemia and normal cytogenetics: interaction with other gene mutations

 

Transformation of follicular lymphoma to diffuse large cell lymphoma is associated with a heterogeneous set of DNA copy number and gene expression alterations

[DOC] Pax 6 Gene Research and the Pancreas

 

Molecular analysis of the cyclin-dependent kinase inhibitor gene p27/Kip1 in human malignancies

Molecular genetic analysis of oligodendroglial tumors shows preferential allelic deletions on 19q and 1p.

Cytogenetic analysis of soft tissue sarcomas: recurrent chromosome abnormalities in malignant peripheral nerve sheath tumors (MPNST)

Radiation-induced genomic instability: delayed cytogenetic aberrations and apoptosis in primary human bone marrow cells

SOURCES

Search:

Gene Mutation Aberration & Analysis of Gene Abnormalities

http://scholar.google.com/scholar?start=20&q=Gene+Mutation+Aberration+%26+Analysis+of+Gene+Abnormalities&hl=en&as_sdt=0,22&as_vis=1

Second:

Sequencing DNA from individual cells vs “humans as a whole.”

Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.

The ability to sequence single cells meant that researchers could take another approach. Working with a team at the Chinese sequencing powerhouse BGI, Auton sequenced nearly 200 sperm cells and was able to estimate the recombination rate for the man who had donated them. The work is not yet published, but Auton says that the group found an average of 24.5 recombination events per sperm cell, which is in line with estimates from indirect experiments2. Stephen Quake, a bioengineer at Stanford University in California, has performed similar experiments in 100 sperm cells and identified several places in the genome in which recombination is more likely to occur. The location of these recombination ‘hotspots’ could help population biologists to map the position of genetic variants associated with disease.

Quake also sequenced half a dozen of those 100 sperm in greater depth, and was able to determine the rate at which new mutations arise: about 30 mutations per billion bases per generation3, which is slightly higher than what others have found. “It’s basically the population biology of a sperm sample,” Quake says, and it will allow researchers to study meiosis and recombination in greater detail.

Fig1a

SOURCES:

http://www.nature.com/news/genomics-the-single-life-1.11710#/genome

Nature 491, 27–29 (01 November 2012) doi:10.1038/491027a

http://pharmaceuticalintelligence.com/2012/11/05/every-sperm-is-sacred-sequencing-dna-from-individual-cells-vs-humans-as-a-whole/

 

Third:

Promising Research Directions By Watson, 1/10/2013

The main reason drugs that target genetic glitches are not cures is that cancer cells have a work-around. If one biochemical pathway to growth and proliferation is blocked by a drug — the cancer cells activate a different, equally effective pathway.

Watson advocates a different approach: targeting features that all cancer cells, especially those in metastatic cancers, have in common.

A protein in cells called Myc. It controls more than 1,000 other molecules inside cells, including many involved in cancer. Studies suggest that turning off Myc causes cancer cells to self-destruct in a process called apoptosis.

cancer biologist Hans-Guido Wendel of Sloan-Kettering. “Blocking production of Myc is an interesting line of investigation. I think there’s promise in that.”

Personalized medicine” that targets a patient’s specific cancer-causing mutation

Watson wrote, may be “the inherently conservative nature of today’s cancer research establishments.”

http://pharmaceuticalintelligence.com/2013/01/09/the-cancer-establishments-examined-by-james-watson-co-discover-of-dna-wcrick-41953/

 

Opinion by Dr. Stephen Willliams, 1/11/2013

Kudos to both Watson and Weinstein for stating we really need to delve into tumor biology to determine functional pathways (like metabolism) which are a common feature of the malignant state ( also see my posting on differentiation therapy).

http://pharmaceuticalintelligence.com/2013/01/09/the-cancer-establishments-examined-by-james-watson-co-discover-of-dna-wcrick-41953/

http://pharmaceuticalintelligence.com/2013/01/03/differentiation-therapy-epigenetics-tackles-solid-tumors/

Fourth:

Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper

Fig2a

Figure’s SOURCE:

Figure brought to my attention by Dr. Tilda Barlyia, 1/10/2013

http://blogs.nature.com/spoonful/2012/12/metabolic-gatekeeper-provides-new-target-for-disrupting-cancer-metabolism.html

Author: Yevgeniy Grigoryev

In the 1920s, the German physiologist Otto Warburgproposed that cancer cells generate energy in ways that are distinct from normal cells. Healthy cells mainly metabolize sugar via respiration in the mitochondria, switching only to glycolysis in the cytoplasm when oxygen levels are low. In contrast, cancer cells rely on glycolysis all the time, even under oxygen-rich scenarios. This shift in how energy is produced—the so-called ‘Warburg effect’, as the observation came to be known—is now recognized as a primary driver of tumor formation, but a mechanistic explanation for the phenomenon has remained elusive.

Now, researchers have implicated a chromatin regulator known as SIRT6 as a key mediator of the switch to glycolysis in cancer cells, a finding that could lead to new therapeutic modalities. “This work is very significant for the cancer field,” says Andrei Seluanov, a cancer biologist at the University of Rochester in New York State who studies SIRT6 but was not involved in the latest study. “It establishes the role ofSIRT6 as a tumor suppressor and shows that SIRT6 loss leads to tumor formation in mice and humans.”

SIRT6 encodes one of seven mammalian proteins called sirtuins, a group of histone deacetylases that play a role in regulating metabolism, lifespan and aging. SIRT1—which is activated by resveratrol, a molecule found in the skin of red grapes—is perhaps the best known sirtuin, but several of the others are now the focus of active investigation as therapeutic targets for a range of conditions, from metabolic syndrome tocancer. Just last month, for example, a paper in Nature Medicine demonstrated that SIRT6 plays an important role in heart disease.

Six years ago, a team led by Raul Mostoslavsky, a molecular biologist at the Massachusetts General Hospital Cancer Center in Boston, first showed that SIRT6 protects mice from DNA damage and had anti-aging properties. In 2010, the same team established SIRT6 as a critical regulator of glycolysis. Now,reporting today in Cell, Mostoslavsky and his colleagues have shown that SIRT6 function is lost in cancer cells—thus, definitively establishing SIRT6 as a potent tumor suppressor.

In the latest study, the researchers showed that mouse embryonic cells genetically engineered to lackSIRT6 proliferated much faster than normal cells, growing from 5,000 cells to 200,000 cells in three days. In contrast, SIRT6-expressiong cells grew at less than half that rate over the same time period. When injected into adult mice, these SIRT6-deficient cells also rapidly formed tumors, but this tumor growth was reversed when the scientists put SIRT6 back into the cells.

“Our study provides a proof-of-concept that inhibiting glycolysis in SIRT6-deficient cells and tumors could provide a potential therapeutic approach to combat cancer,” says Mostoslavsky. “Additionally, SIRT6 may be a valuable prognostic biomarker for cancer detection.”

Currently, there are no approved anti-glycolytic drugs against cancer. However, the latest findings indicate that pharmacologically elevating SIRT6 levels might help keep tumor growth at bay. And there’s preliminary data to suggest that the work will translate from the bench to the clinic: looking at a range of cancers from human patients, Mostoslavsky’s team showed that the higher the level of SIRT6 the better the prognosis and the longer the survival times.

SOURCE:

Fifth:

Molecular Analysis of the different Stages of  Cancer Progression: The Example of Breast Cancer 

Fig2b

Figure’s SOURCE:

The molecular pathology of breast cancer progression

Alessandro Bombonati1 and Dennis C Sgroi1,2* Journal of Pathology, J Pathol 2011; 223: 307–317

(wileyonlinelibrary.com) DOI: 10.1002/path.2808

http://onlinelibrary.wiley.com/store/10.1002/path.2808/asset/2808_ftp.pdf;jsessionid=26C2C424E6948A5FAF3CBADBA385184A.d02t04v=1&t=hi26qzd4&s=a8a4aadb3fc6d448080c0ef3c67415b8277145aa

Post by Dr. Tilda Barlyia and Comments on   “The Molecular Pathology of Breast Cancer Progression”

http://pharmaceuticalintelligence.com/2013/01/10/the-molecular-pathology-of-breast-cancer-progression/

Conclusion

The Paradigm Shift in Human Genomics will follow the following FIVE DIRECTIONS:

  • No to Sequencing Patient’s DNA, No to Sequencing Patient’s Tumor, Yes to focus on Gene Mutation Aberration & Analysis of Gene Abnormalities
  • Sequencing DNA from individual cells vs “humans as a whole.” Sequencing DNA from individual cells is changing the way that researchers think of humans as a whole.
  • Promising Research Directions By Watson, 1/10/2013
  • Disruption of Cancer Metabolism targeted by Metabolic Gatekeeper
  • Molecular Analysis of the different Stages of  Cancer Progression for Targeting Therapy

Read Full Post »

Reporter: Aviva Lev-Ari, PhD, RN

Personal Tale of JL’s Whole Genome Sequencing

Word Cloud by Daniel Menzin

Unexpected scary findings: the tale of John Lauerman’s whole genome sequencing

FEBRUARY 15, 2012
Joe Thakuria draws John Lauerman's blood
Joe Thakuria draws John Lauerman’s blood for whole genome sequencing. By Madeleine Price Ball, licensed under CC-BY-SA.

Madeleine Price Ball, PhD is a PGP research scientist in George Church’s lab at Harvard Medical School.

Several months ago John Lauerman, a reporter for Bloomberg News, approached the Personal Genome Project interested in having his whole genome sequenced. While we have hundreds of genomes in the sequencing pipeline, of the dozen or so genomes we have sequenced to-date, so far the results have been for the most part uneventful.

Lauerman’s case was different: we found something rare and “famous”, and something that nobody could have anticipated by looking through family history: a mutation that was acquired rather than inherited. This genetic variant (JAK2-V617F) is one of a number of mutations that can accumulate in blood stem cells, a precursor that could lead to several rare blood diseases.

Last night Lauerman published his experience, and we encourage all participants to read it. It confronts us with a scenario that seems likely to affect others who forge into this new and unknown territory: the very real possibility that whole genome sequencing may uncover something unexpected, ambiguous, and scary. This certainly isn’t an outcome we anticipate for most participants, but it is a rare possibility all should be aware of. Would you rather know that you carry such a variant, even if that knowledge might not help your health at all? Although some would decline, PGP participants are the sort of people who say: “Yes, I’ll take that risk, I’d rather know!” [see footnote]

His experience also illustrates potential for the Personal Genome Project to guide health care, for himself and for those who follow. The JAK2-V617F variant is so rarely seen in healthy individuals, we have very little understanding of what to expect. It has almost always been seen after a patient is diagnosed with a disease, not before. Will he develop one of these diseases? If so, which one? Perhaps many people carry the variant but never develop any symptoms of disease. In coming years Lauerman will likely continue to monitor his blood for signs of disease. It is possible that he will never develop the disease, and we hope this is the case. On the other hand, through monitoring he may detect disease sooner than he otherwise would have. By making his experiences public, his case can inform future individuals who confront the same finding.

As we move onward to sequencing hundreds and thousands of genomes, we can’t promise such interpretations will be made in a timely manner. We’re working with other groups to improve our ability to interpret genomes — and PGP participants are the perfect testbed for this development! — but it’s much harder than you might think. Genome data is made public in 30 days, but months or even years could pass before a serious and potentially scary variant is noticed. Participating in the PGP not only means that you risk learning ambiguous and scary news, but that it may be uncovered long after your data has been made public. We are always grateful to participants who choose to step into that unknown territory of genome sequencing, and who share their data so that others may learn.


Footnote: In the early stages of enrollment, individuals interested in joining the Personal Genome Project are asked to think about whether there are specific types of genetic information that they might not want to learn about themselves. Our examples include medical conditions with no effective cures or therapies, cancer, degenerative diseases, and stigmatized traits (e.g. mental illness). We do not offer the review or redacting of such information on a case-by-case basis. Only participants who wish to take the risk of learning such information are allowed to proceed with enrollment.

SOURCE:

http://blog.personalgenomes.org/2012/02/15/unexpected-scary-findings-the-tale-of-john-lauermans-whole-genome-sequencing-2/lauerman_blood_draw/

http://www.personalgenomes.org/

Harvard Mapping My DNA Turns Scary as Threatening Gene Emerges

By John Lauerman – Feb 15, 2012 12:01 AM ET

Four months after I walked into a lab at Harvard University and gave a vial of blood to have my genome sequenced, my search to understand my DNA led me to Mark Sanders, a former Indiana firefighter.

It took a little while to explain why I was calling and then he told me his story:

Sophie Liu, research scientist at Complete Genomics Inc., at a sequencing center at the company’s research facility in Mountain View, California. Photographer: David Paul Morris/Bloomberg

Feb. 15 (Bloomberg) — Bloomberg News reporter John Lauerman talks about the results of his genome sequencing. The genome contains the DNA instructions for making all the body’s cells and tissues. Lauerman discussed the report with a team from Harvard Medical School’s Personal Genome Project, who will use the results in their efforts to better understand variations in the human genome and their implications for health and disease. (Source: Bloomberg)

Joseph Thakuria, clinical director of the Personal Genome Project draws blood from Bloomberg reporter John Lauerman for the Project at Harvard Medical School in Boston on Sept. 13, 2011. Photographer: Madeleine Price Ball/Harvard Medical School via Bloomberg

Deep Breath

After recovering, Sanders retired from firefighting to garden and play the fiddle. He knows other myelofibrosis patients who haven’t fared as well.

“I had been so physically fit all my life,” he said. “There’s no reason or rhyme to why I have it or got it, and there’s not a lot of people around you can talk to who have it.”

I hung up the phone and took a deep breath. DNA in his blood cells carried the same rare genetic variant that my sequencing had revealed.

The variant is linked to a group of blood disorders, of which primary myelofibrosis is the most serious. Doctors don’t know whether this gene variant itself causes disease, yet it is seen so often in three blood disorders that its presence is used to confirm their diagnosis. I had to consider that my future might hold a fate similar to Sanders’s.

Genome-Sequencing Report

My path to Sanders began on Monday, Jan. 2, when I was sitting alone in my office in downtown Boston. Just after 4 p.m., I got an e-mail message from Madeleine Ball, a Harvard University researcher, telling me that the results of my genome sequencing were ready. The procedure is gaining use in cancer clinics and children’s hospitals, and will become increasingly common as the cost drops to $1,000, no more than that of many diagnostic procedures, such as MRI or colonoscopy, manufacturers and researchers say.

Before even a minute had gone by, the lengthy report was there for me to view.

“Here it is,” I thought, clicking on my inbox. “Mortality in an e-mail.”

Even as my DNA was chopped up, labeled, photographed and decoded by machines in California, the speed and power of sequencing was exploding. Life Technologies Corp. (LIFE) said Jan. 10 that its new Ion Proton machine will be able to sequence an entire genome in a day, for $1,000. Last month,Roche Holding AG (ROG) made a $5.7 billion hostile bid forIllumina Inc. (ILMN), which said it will also soon have machines that can provide 24-hour genome sequencing. Google Inc. (GOOG) and Amazon.com Inc. were investing in technologies to manage the tidal wave of information coming from these machines.

Personal Struggle

Now my own deciphered genome, the chemical instructions for making all the cells and tissues of my body, was complete. That evening marked the start of a medical and personal struggle to understand the report’s findings. The genome rules our bodies in ways that remain enigmatic. Many of the diseases and medical conditions I thought would emerge in the analysis, didn’t. At the same time, there were unpleasant surprises that cast a shadow on my future and now confront me and my family with tough medical decisions.

Before my sample was taken, I met with Denise Lautenbach, a genetic counselor who works in research programs at Harvard Medical School. We’d discussed the possible revelations that might come. My father, grandfather and some uncles have suffered from a shaking disorder called essential tremor. I worried about other conditions that run in my family, such as thyroid disease, diabetes and depression. While dementia isn’t a theme, I was curious about whether I have the APOE4 gene variant that raises the risk of Alzheimer’s disease.

Breast Cancer Risk

I also prepared by speaking with others who have had their genomes sequenced. Greg Lucier, chief executive officer of sequencer maker Life Technologies, discovered he has a gene that might raise the risk of breast cancer in himself and his daughter. Would I find out the same thing? What about far rarer conditions, such as amyotrophic lateral sclerosis and Huntington’s disease, both of which can be predicted by sequencing?

My mind raced as I scanned the results that late Monday afternoon, looking for familiar words and phrases that might be connected to other conditions that run in my family.

Good Report

It appeared to be a good report. I saw a genetic variant linked to slightly higher-than-normal risk of an age-related eye disease called macular degeneration. No surprise; about 10 percent of the U.S. develops this condition, and my mother has it. There was a variant linked to higher schizophrenia risk; again, not a huge boost in odds of a disease that affects about 1 percent of the population (and which I’m probably too old to develop). There were gene variants linked to liver and bowel disease, neither of which I suffer from.

Then my eyes were drawn back to the top of the report and a variant called JAK2-V617F. I realized then that the list was ranked in order of medical importance. Clicking on an entry brought me to a few pages of medical information, and those pages were linked to published scientific and medical studies. I began reading about JAK2 more closely.

This wasn’t good. The report classified the JAK2 variant’s clinical importance as “high,” and its impact as “well- established pathogenic,” meaning harmful. It’s seen frequently in people with rare “cancer-like” blood diseases. Indeed, as the report said, doctors test for the JAK2 variant to confirm cases of these diseases, called myeloproliferative disorders.

Unclear View

Did that mean that I already had a rare disease? My eyes widened. I read on.

Researchers currently see the variant as “one of an accumulation of changes that leads to the development of these cancer-like diseases,” the report said. “It is unclear how to view the presence of the variant in people who don’t have symptoms of the disease.”

After about 40 minutes of reading and thinking, I remained mystified. The report said “cancer-like.” I kept staring at the word “cancer,” while the companion “like” seemed to disappear. I’ve written about other people’s illnesses for years. What had started out as a cutting-edge science story was beginning to feel more like an unsettling visit to the doctor’s office with its confusion, struggles to understand, and shivers of dread.

Puzzling Medical News

“How worried should I be?” I kept thinking. Anticipation had been building inside me for months. Now my results were here and I barely knew what to make of the most important one.

I picked up the phone and called my wife, Judi, who’s a nurse. After 21 years of marriage, we’re accustomed to regular discussions of medical issues, in part because Judi has type 1 diabetes, which requires daily monitoring and insulin. Still, this was some of the most serious and puzzling medical news I’d ever received. I was careful to keep from sounding frightened.

“I got my results,” I said when she picked up the phone. I poured out the details, focusing on the JAK2 variant.

Judi’s voice was calm. I didn’t have any of the symptoms of diseases associated with the gene, she said. I’m usually energetic and active; that meant it wasn’t clear what the variant meant in my case.

“At least if there is a problem, we’ll find it earlier if you’re evaluated yearly,” she said.

“They told me that none of these results should be used to make medical decisions,” I said. “I’ll meet with the researchers later this week to talk about everything.”

New Chapter?

We agreed that, overall, the report was good news. I didn’t realize there was more news to come.

I left the office and got on my bike, which I had ridden to work that day. I pedaled carefully to make it home safely through the streets of Boston, which is never guaranteed, genes or no genes.

Three days after getting my results, I took a seat in the office of George Church, the Harvard scientist who started the Personal Genome Project that arranged my sequencing. Joe Thakuria, the clinical geneticist and project medical director who took my blood sample in this same office in September, was there to lead the discussion of my results. The team had been through meetings like this before, having analyzed and released the genomes of 10 people, including Church, in 2008. I was already feeling a stomach full of emotions: was this about to be a new chapter in my life? And if so, how long would that chapter be?

Thakuria asked if I had any questions before we began. I told them how thrilled I was that I hadn’t seen certain genes that I expected given my family’s medical history, such as the variant for essential tremor. I’d seen nothing in my report about Alzheimer’s risk, which I considered a good sign.

Not Bad News

The researchers stopped me. The technology used to sequence my DNA has difficulty penetrating certain portions of the genome. One such region contains the gene that makes a blood fat called apolipoprotein E. Consequently, my results might not show whether I have the version of a gene, called APOE4, which raises the risk of Alzheimer’s disease.

Never mind, I thought. I can live without that knowledge.

The absence of the gene for benign tremor, the condition my father and grandfather had, wasn’t necessarily such good news, the team explained. As-yet unknown genes might cause the same condition. No news wasn’t always good news; it just wasn’t bad news.

‘Very Rare’

With the three of us, along with Ball and Alexander Zaranek, another project researcher, crowded around the table in Church’s office, the team then turned to the JAK2 variant. The appearance of the gene in my blood had surprised even the Harvard scientists.

“This is probably the most serious variant that we’ve actually seen to date in the study,” Thakuria said. “It’s very rare.”

The JAK2 gene contains the DNA code for making a protein used to send signals through cells. About two out of 1,000 people have the V617F variant, which was discovered in 2005 and appears to encourage blood cells to grow and divide.

Many scientists believe it’s an acquired gene variant, meaning that I wasn’t born with it and my children and other blood relatives probably don’t have it. While JAK2 may have arisen in response to my own habits, at this point, it’s unclear what may have led to the mutation.

Blood Disorders

The JAK2 variant is found in about 90 percent of people with polycythemia vera, an oversupply of red blood cells. This disease is usually treated with drugs or phlebotomy, the draining of some blood from the system. It’s also frequently found in patients with essential thrombocytosis, an overproduction of platelets that usually requires no treatment and can be addressed with blood-thinners when patients have symptoms. It’s also used to diagnose primary myelofibrosis, the condition Sanders, the former firefighter, had. About 10 percent of these cases can develop into dangerous leukemias.

That’s three conditions linked to one gene. One of the three has a possibility of becoming cancerous, Thakuria said.

“I don’t want you to fret about this,” he said. It was the first of several times I would hear him say it.

At that point, Thakuria opened up a link to a 2010 study attached to the report. Scientists have been conducting studies of individual genes for years. The team had found a study of 10,507 people in Copenhagen who gave blood samples and then were followed for as long as 18 years. The Copenhagen researchers went back and analyzed the blood samples; 18 had the JAK2 variant.

‘Very Scary Figure’

What it showed was that 14 of the 18 people with the variant developed cancer in their lifetimes. All of the 18 died within the study period.

“That’s a very scary figure,” Thakuria said.

Information was starting to wash over me without really penetrating. I struggled to keep thinking of good questions for the team. Instead, I started asking myself questions: “What am I doing here? What are these people telling me?” I searched the faces arrayed around me, trying to see whether any of the researchers looked as panicked as I felt.

I tried to listen closely as Thakuria explained what the variant and the study might mean. There were a number of shortcomings in the Copenhagen study that made it difficult to interpret, he said. For example, he said, the authors had been liberal in their use of the word “cancer.” Some of the disorders developed by patients with the JAK2 variant were of the milder variety such as polycythemia vera, which isn’t typically classified as a cancer.

Issue of Deaths

Then there was the issue of deaths. It wasn’t clear whether people with the variant had died of the conditions they had been diagnosed with, or other causes, Thakuria said. Half of them had died in their 80s, and seven had died in their 70s. This is not far from average life expectancy, he pointed out.

“Half of them could have died of bicycle accidents,” he said, smiling.

There were other reasons not to fret, Thakuria said. Although the JAK2 variant often shows up in these conditions, no one knows precisely what role it plays. It may be a cause of the disorders, or an effect of changes elsewhere in the genome. The JAK2 variant was unlikely to be the only cause of these diseases; several things — things that remain unknown to us — would probably have to go wrong before any disease would arise. In this context, the gene wasn’t quite so scary, Thakuria said.

Black and White

I thought about a conversation I’d had with Ball just a few days earlier, while my genome were still being analyzed. I had called to see when the results were coming. She said they were “interesting,” but didn’t want to discuss them until a clinical geneticist had a chance to review them. Her voice sounded like she didn’t want to reveal everything she knew.

“I wish everything were black and white,” she said. “Unfortunately, things just don’t turn out that way very often.”

The researchers said I now needed to confirm that the sequencing was correct with another round of testing using a different technique. I would give another blood sample. If the variant was there, we’d talk more about what steps to take.

The meeting lasted almost two hours, and I left Church’s office with Thakuria. We walked to a restaurant about halfway between Harvard Medical School and Fenway Park to sit and have a drink. I continued to quiz him on the relationship between the JAK2 variant and the diseases we’d been talking about.

Ask Again

Sitting on a barstool next to Thakuria and listening to him discuss the JAK2 variant, I felt reassured. It occurred to me that this wasn’t how most people would receive the news of their results. As a reporter working on a story about genomics, I had access to experts that many people wouldn’t. What will happen as more people get results from broad genome sequencing?

I spoke about this during a meeting with Harold Varmus, director of the U.S. National Cancer Institute, and a co-winner of a Nobel Prize in 1989 for his work to find genes that promote the growth of cancer cells. I mentioned I had just received my results.

“How do you feel?” he asked.

“It’s been an interesting process,” I said. “It’s still playing out.”

Varmus nodded. Gathering genetic data from thousands of people can help researchers understand health by correlating gene variations with diseases, he said. He was concerned, however, that companies may not always ensure that people who have undergone sequencing will get a full understanding of their results.

‘How to Deal’

“Accumulating the information and studying it is good,” he said. “My concern is whether individuals are getting guidance on how to deal with the information.”

“People are being told they have a certain gene variant. In a mass population, that increases the risk of some diseases by, say, two-fold. That might be true in a mass population, but in any single individual’s genome, it’s not certain what that means.”

The Harvard researchers are struggling with these same issues, and are still working to streamline and improve their approach to giving results to study participants, Thakuria said.

“As we get more information from participants like you, we’ll gain a much better understanding of how to do it,” Thakuria said.

Animal Studies

I still felt like someone who kept shaking a toy Magic 8 Ball and getting the message: “Concentrate and ask again.” I decided to do a little research on my own. I found a 2010 study in the journal Blood showing that when the JAK2 variant was added to the genomes of mice, the animals later suffered from disorders similar to those seen in people with the gene.

This is just one of several animal studies suggesting that the JAK2 variant contributes directly to blood disorders, said John Crispino, a professor at Northwestern University Feinberg School of Medicine, who studies the gene. Skeptics point out that drugs that interfere with JAK2 don’t cure patients suffering from the gene-linked blood disorders.

“The field is mixed,” he said. “My bias is that the JAK2 variant contributes to the pathology of the disease.”

I wanted to find out what kind of people have the JAK2 mutation I have, and what’s happened to them. In addition to Sanders, the Indiana firefighter, I spoke with Bob Rosen, chairman of theMPN Research Foundation, a Chicago-based advocacy group for people with myeloproliferative disorders, and he had a surprise for me.

Red Blood Cells

About 14 years ago, Rosen went to a doctor because of pain in his fingers and toes. A complete blood count revealed high levels of red blood cells. He was diagnosed with polycythemia vera and was first treated with phlebotomy. He now takes a drug that controls his blood cell levels. With his treatment, he’s still able to work out, and had been playing basketball on the day I called him.

“I’ve been lucky,” he said. “The risk is that, over time, new symptoms will emerge or there will be a progression to something worse.”

A small percentage of patients with polycythemia vera can develop more serious conditions, such as primary myelofibrosis and certain leukemias, Rosen said. I hadn’t realized this, or hadn’t absorbed it, until now.

Another Surprise

Then, another surprise arrived. Looking at my report, I saw it had been updated electronically, as the genome project research team had told me would happen from time to time. Now, the second entry on my list of variants was labeled “APOE- C130R” — that’s another name for the APOE4 gene associated with increased risk of Alzheimer’s disease.

I kept reading, recalling that I had been told my ApoE result wasn’t accessible with the technology used to sequence my genome. As it turned out, the technology had worked after all. I was at increased risk for Alzheimer’s.

This was exactly the kind of news I had hoped I wouldn’t receive.

A few days later I got an e-mail from Ball, of the Harvard team.

“Sorry this was missed earlier,” she said in the e-mail. She recommended that I look at the studies she’d collected on APOE4, some of which casts doubt on the role of the variant as a strong factor in causing Alzheimer’s. According to one estimate, people who have one copy of the gene, as I do, have a 3 percent increased risk of developing the disease by age 80.

Better to Know

One of my parents must have had this gene variant in order for me to get it. Yet my mother is in her late 70s and my father is 80; neither of them has Alzheimer’s disease. The longer I thought about it, the less I worried.

I talked with my two children, Hanna and James, about their feelings regarding the JAK2 and Alzheimer’s gene variants. My daughter, a sophomore in college, said she thinks it’s an advantage to be aware of a health threat.

“If there’s a treatment for it, you could start earlier,” she said. “It’s better to know.”

My next stop was to see my doctor. While she didn’t want her name used in this story, she agreed to let me write about our conversations and paraphrase her comments.

I followed an aide into an exam room. Nothing about my body had changed since the genome test was done. I still had normal blood pressure and pulse, and my weight was steady.

My doctor had heard of the JAK2 variant. If the result was confirmed, I would need to have my blood count tested. If there was an oversupply of red blood cells or platelets, or signs of damaged bone marrow, we would start thinking about treatment, such as removing blood. She asked me how I was feeling.

‘Not Sick’

“I feel fine,” I said. “I’m not sick.”

I didn’t mention that every time I thought about the JAK2 variant, itching followed. I had read that itching was one of the symptoms of polycythemia vera. Even as I write these words, I’m scratching my forehead. I never feel itchy when not thinking about my genome. I also started noticing memory lapses.

This kind of behavior is often called “medical student syndrome,” because doctors in training who are learning to diagnose new diseases turn their skills on themselves. I assumed it was this syndrome I was suffering from, rather than a blood disorder.

It seemed like a good time to return to the Boston office of Aubrey Milunsky, the director of the Boston University Center for Human Genetics who had warned me in May that having my genome sequenced would just cause me needless worry.

“Why would you want to know that?” he had asked me then.

Milunsky was well-acquainted with the JAK2 variant on my report. Just as the team at Harvard had said, he mentioned that there was little known about the long-term impact of the variant in people. He noted that it’s also associated with some cases of dangerous clotting in abdominal blood vessels.

“You know it’s there, but you don’t know what it means,” he said. “You’re smack in the territory of inviting anxiety into your life. And this may have no meaning whatsoever in your entire life.”

Useful Vigilance

I disagreed. The results had actually taken some uncertainty out of my life, I told Milunsky. We all bear some health risks, and that’s why doctors recommend, for instance, that everyone get regular checkups and those 50 and older undergo tests for colon cancer. I have a rare mutation linked to rare conditions, most cases of which can be treated. Wouldn’t it make sense for me to undergo a blood test regularly to see whether my blood counts had changed?

Such vigilance might be beneficial, and it might not, Milunsky said. I might live the rest of my life with my health unaffected by the variant. Yet the exercise had shown that I had discovered things I’d rather not know, he said. Others who undergo the same procedure will surely find out that they have mutations that practically guarantee they will develop serious and perhaps even fatal diseases, he said.

Huntington’s Disease

Indeed, a 1999 study in the American Journal of Human Genetics found that about 1 percent of 4,527 people who were told they had the gene that causes Huntington’s disease, a progressive nervous system disorder, attempted or committed suicide, or were hospitalized for psychiatric reasons.

Medical researchers are still trying to determine when it makes sense to do more common tests for breast and prostate cancer. A certain percentage of people who get positive results on these screening exams will go on to have unneeded treatment that may cause harm. In October, a government panel recommended that blood tests used to screen for prostate cancer should only be performed on men with symptoms. The same panel said in 2009 that women should start getting mammograms at age 50, rather than 40.

On Jan. 25, at about 11 p.m., I got a phone call from Thakuria. We had arranged to speak late in the day to accommodate busy schedules.

‘Mutation Confirmed’

“The mutation confirmed,” he said. He didn’t say “JAK2,” but I knew that was what he was talking about.

The next step for me is to have my white and red blood-cell levels measured, along with those of platelets. Doctors will also study the appearance of these cells under a microscope and check to see how much oxygen my blood can carry. I expect these tests to be normal. If they aren’t, it’s possible that I’ll start getting blood drawn from my system or drug treatment for polycythemia vera. I may need to take a blood thinner, such as aspirin, to counteract the effects of excess platelets. Should I have evidence of more serious disease, stronger treatment may be needed.

“I’m not going to lie to you: I’d rather you didn’t have it,” Thakuria said. “This isn’t like one of those mutations that have specific recommendations. There are no guidelines here. This is part of being on the frontier.”

To contact the reporter on this story: John Lauerman in Boston at jlauerman@bloomberg.net

To contact the editor responsible for this story: Jonathan Kaufman at

jkaufman17@bloomberg.net

SOURCE:

http://www.bloomberg.com/news/2012-02-15/harvard-mapping-my-dna-turns-scary-as-threatening-gene-emerges.html

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How Genome Sequencing is Revolutionizing Clinical Diagnostics, from the ISMB Conference

Reporter: Aviva Lev-Ari, PhD, RN

 

08WednesdayAug 2012

Written by Filipe J. Ribeiro in Events

Filipe Ribeiro New York Genome CenterFilipe J. Ribeiro is a Bioinformatics Scientist at the New York Genome Center.

Recently, I attended the 20th Annual Conference of Intelligent Systems for Molecular Biology (July 15-17, 2012), organized by the International Society for Computational Biology. The conference focuses on the application of computer science, statistical, and mathematical methods to biological systems. I also attended the High Throughput Sequencing Methods and Applications (HiTSeq) satellite meeting (July 13-14, 2012). There, the speakers addressed the opportunities and challenges presented by the availability of the increasingly large genomic datasets from next-generation sequencing.

Many topics were discussed during the two days of HiTSeq, such as new data-analysis methods for RNA sequencing data, methods for improving de novoassemblies, and sequencing-data compression. What impressed me the most were the keynote addresses given by Dr. Stanley Nelson, from the Jonnson Comprehensive Cancer Center at UCLA, and Dr. Gohlson Lyon, from Cold Spring Harbor Laboratory. Both speakers focused on how whole-exome andwhole-genome sequencing are on the verge of revolutionizing clinical diagnosis of genetic disorders and what challenges need to be addressed before sequencing penetrates the clinic.

Dr. Nelson’s talk centered on the use of exome sequencing in the clinical diagnosis of genetic conditions. He presented a few case studies of young children with various rare developmental delays. Rare conditions can be hard to diagnose, and often times numerous tests need to be performed before a conclusion is reached, if a conclusion is reached at all. Also, some conditions are caused by a variety of different mutations to a single gene. These are harder to detect with conventional targeted genetic testing, which relies on known mutations. With exome sequencing a single test is performed; that one test identifies all coding mutations, known and unknown, simple and complex. Even when there is no smoking gun in the large set of mutations typically found in any single individual, the genotype can be reanalyzed at a later point, in light of new research findings.

However, challenges in genomics-based diagnosis still remain. Dr Nelson reports that in roughly 50 percent of cases studied clinically at UCLA, a known causal mutation is found. In 25 percent of cases, a novel genetic mutation is identified that is potentially causal, and in the remaining 25 percent of cases no conclusion can be drawn. Because of the large number of novel mutations that are present in any single individual’s genome, establishing causality of novel variations is often very hard, and care must be taken when interpreting results in order to avoid false positives. To minimize the risk of misdiagnosis in a clinical setting, it is fundamental to have a board of scientists and clinicians to review the conclusions of sequencing tests to ensure their validity.

Another challenge is what to do with secondary or unrelated findings—for example when a patient comes in with a set of symptoms indicative of one condition, and the genetic test finds a different one that is unrelated and asymptomatic. Some conditions (like Huntington’s disease) have no cure, and the patient might not want to learn about any diagnoses that are not actionable. A great deal of care must be taken both before and after genetic testing takes place so that patients understand the risks and the meaning of results.

On a slightly different note, Dr. Lyon focused on the ethical difficulties of returning research-grade results on genetic disorders to study participants. As an example he presented the case of a family that carries a genetic mutation that is fatal in boys at a very early age. A mutation was identified and shown to be causal in a research setting. The ethical dilemma for the researcher is: if one of the women in the family is pregnant with a boy, should she be informed of her carrier status? Research standards are not at the same level as clinical ones, and research results can at times be wrong.

It is not an easy question. Dr. Lyon’s suggestion is that research-grade whole-genome and whole-exome sequencing of study participants should be conducted under the same CLIA-certified standards as clinical tests, with the goal of returning research results to the study participants. Again, counseling and education of study participants regarding the risks and benefits of genetic testing are critical.

One barrier to the adoption of sequencing in a clinical setting is the fact that insurance companies do not cover the costs of whole genome sequencing as they are not yet convinced of the benefits. But that attitude will hopefully change as sequencing costs keep decreasing, and success stories abound. Soon it will be clear that genome sequencing is cost effective in disease diagnosis, prevention, and treatment. Also, for the most part genome sequencing is done only once in a lifetime, and therefore it is not a repetitive cost. (Cancer is an exception; one might want to sequence the cancer cells to identify which specific mutations are driving the tumor and to what drugs the tumor might respond.)

In summary, both speakers painted a picture of how whole-genome and whole-exome sequencing is quickly proving itself as a revolutionary tool in the clinic. Clearly challenges remain: test interpretation must be done carefully, ideally by a board of both scientists and clinicians, and strict CLIA standards should be in place, even in a research setting. But it is certainly clear that next generation sequencing will play an increasingly significant role in the clinic, and, most importantly, in our health.

 

http://blog.nygenome.org/

 

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