Part 1 of a series on genes and mental health. Taken from an article published in Therapeutics Daily.
Two genes have been identified as associated with schizophrenia:
- GCPII (glutamate carboxypeptidase II), which controls the absorption of folate and may be deficient in people with schizophrenia,
- MTHFR (methylenetetrahydrofolate reductase), which activates folate for use in the brain
Donald C. Goff, MD, director of the Schizophrenia Clinical and Research Program at Massachusetts General Hospital and a leading researcher on the role of genetics in the development of new treatments for schizophrenia, pioneered research that identified a link between low blood levels of folate and negative schizophrenia symptoms. Folate, given routinely to pregnant women as folic acid and often recommended for maintaining brain health in the elderly, is (according to the article) "involved in many different chemical pathways in the brain, including keeping levels of the amino acid homocysteine low. When homocysteine levels are too high, this interferes with the functioning of receptors located all over the brain -- called NMDA ( N-methyl-D-aspartate) receptors -- that are critical to learning, memory, brain development, and general neural processing."
So far, many of my posts on genetic testing have been focused on the availability of testing, quality of testing, and interpreting the results. I'm getting a bit bored--and perhaps you are too--of repeated suggestions that genetic testing available to the public is not yet as useful as headlines often state. If you haven't gotten the message yet, read some of the old posts in this theme.
Today, I want to move on to ways in which scientists and physicians are using the results of targeted genetic testing--that is, working with a specific gene rather than the whole genome--to identify potential therapies for conditions that are not fully responding to current therapies.
Here's an article from Medical News Today about genetic testing:
A new report on genetic testing from HHS' Agency for Healthcare Research and Quality calls for the creation of improved public health surveillance databases and health information technologies to monitor the use of gene-based tests and their impact on patient outcomes.
Funded by Centers for Disease Control and Prevention, the report entitled, Infrastructure to Monitor Utilization and Outcomes of Gene-based Applications: An Assessment, found current public health monitoring systems lack the capability to monitor the use or outcomes of gene-based tests and treatments. Report authors identified several limitations of existing databases and potential solutions to overcome these limitations.
Researchers agreed that the development of gene-based tests is outpacing the evaluation of their accuracy and clinical utility. Gene-based tests may, in some cases, help make early diagnosis of a disease, improve risk prediction, and target therapies for both traditional gene-based disorders as well as common chronic diseases. However, since all tests and treatments are not expected to have the same amount of benefit, experts said it is important to distinguish beneficial tests and treatments from those that have little or no benefit or that may even harm the public.
Many gene-based tests are only recommended for people with certain risk factors. For example, the U.S. Preventive Services Task Force recommends primary care physicians should refer only high-risk women for genetic counseling and testing to detect gene mutations associated with breast or ovarian cancers. The Task Force recommends that women who do not have a family history of either breast or ovarian cancer and are unlikely to test positive for the mutations should not be referred for testing, as there are potential harms involved in genetic testing including false-positive test results. Also, the Task Force recommends against routine genetic screening in the general population for Hereditary Hemochromatosis, a genetic disease that causes the body to absorb and store too much iron.
Better monitoring capabilities would help identify which gene-based tests improve patient outcomes and are cost-effective, researchers found. By 2009, the world market for gene-based testing is expected to reach $12.5 billion.
More than 1,000 gene-based tests are now available to consumers via their clinicians, and many more are expected to become available in the near future. Some of these tests are marketed directly to consumers. The Federal Trade Commission has issued a consumer alert on at-home genetic testing and urges consumers to be skeptical of claims made by companies that are marketing these tests directly to consumers. AHRQ recommends patients consult with their clinicians to evaluate their risk factors and determine their need for genetic testing.
The report is available online.
Here's the latest from Genetic Alliance and The Coalition for Genetic Fairness (copied directly from the news release):
Washington, D.C. – May 21, 2008 – The Coalition for Genetic Fairness (http://www.geneticfairness.org/) commends President George W. Bush for signing into law today the first civil rights legislation of the new millennium, the Genetic Information Nondiscrimination Act (GINA). GINA is the first and only federal legislation that will provide protections against discrimination based on an individual’s genetic information in health insurance coverage and employment settings.
“This is a tremendous victory for every American not born with perfect genes – which means it’s a victory for every single one us,” said Representative Louise Slaughter (D-NY). “Since all of us are predisposed to at least a few genetic-based disorders, we are all potential victims of genetic discrimination.”
“Today marks the beginning of a new era in health care,” continued Slaughter. “Americans can finally take advantage of the tremendous potential of genetic research without the fear that their own genetic information will be used against them.”
Just a few weeks ago, GINA received overwhelming support in both the Senate, with a unanimous vote of approval, and the House of Representatives, where the legislation was passed by a landslide vote of 414-1.
”Individuals no longer have to worry about being discriminated against on the basis of their genetic information, and with this assurance, the promise of genetic testing and disease management and prevention can be realized more fully,” stated Sharon Terry, president of the Coalition and CEO of Genetic Alliance (http://www.geneticalliance.org/).“We applaud our champions on the Hill who have worked tirelessly to pass this important legislation. It is now our responsibility to make sure the public knows that these new protections are in place.”
The health insurance protections offered by GINA are expected to roll out 12 months after the bill is signed, whereas the employment protections will be fully realized in 18 months.
“Now that GINA has been approved and signed into federal law by the President, American health care consumers and employees will no longer have to fear the adverse effects of being tested to determine their risk status for genetic diseases,” said Joann Boughman, Ph.D., executive vice president of the American Society of Human Genetics (http://www.ashg.org/) and a member of the Coalition’s executive committee. “Once this legislation has taken effect, clinicians will be able to order genetic tests for patients and their families in a manner that ensures the full realization of the advantages of personalized medicine models, while easing patients’ concerns about the risk of genetic discrimination by insurance companies and employers based on this data.”
Specifically, the legislation protects against genetic discrimination by health insurers or employers by:
• Prohibiting group health plans and issuers offering coverage on the group or individual market from basing eligibility determinations or adjusting premiums or contributions on the basis of genetic information. They cannot request, require or purchase the results of genetic tests, or disclose genetic information.
• Prohibiting issuers of Medigap policies from adjusting pricing or conditioning eligibility on the basis of genetic information. They cannot request, require or purchase the results of genetic tests, or disclose genetic information.
• Prohibiting employers from firing, refusing to hire, or otherwise discriminating with respect to compensation, terms, conditions or privileges of employment. Employers may not request, require or purchase genetic information, and may not disclose genetic information. Similar provisions apply to employment agencies and labor organizations.
Time magazine includes an essay in response to sending GINA (Genetic Information Nondiscrimination Bill) on to the President for his signature.
Sidenote: why hasn't he signed it yet? Perhaps he's setting up a good photo op akin to the carrier picture.
Anyway, Michael Kingsley thinks that discrimination on the basis of genetic information is no different from any other type of actuarial discrimination followed by the insurance companies. After all, they reject customers with other problems (diabetes, cancer, etc.), why not genetic information?
Just returned from a conference in Cleveland, Ohio, dealing with the many different aspects and potential effects of sequencing the human genome. I'll write in the next couple of days about items that particularly interested me.
But first, what is genomics?
I hate to admit it, but when I first joined a group at the Utah Department of Health to discuss genomics, I had no idea what it was. Surprising to me was the fact that others gave me quick definitions, but they varied considerably. So, here's some of the ones you might consider:
Wikipedia: Genomics is the study of an organism's entire genome. The field includes intensive efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping efforts. The field also includes studies of intragenomic phenomena such as heterosis, epistasis, pleiotropy and other interactions between loci and alleles within the genome. In contrast, the investigation of single genes, their functions and roles, something very common in today's medical and biological research, and a primary focus of molecular biology, does not fall into the definition of genomics, unless the aim of this genetic, pathway, and functional information analysis is to elucidate its effect on, place in, and response to the entire genome's networks.
In response to the increasing availability of genetic tests the American College of Medical Genetics has issued a policy statement on direct-to-consumer genetic testing. It includes five minimum requirements for any testing protocol:
- A knowledgeable health professional should be involved in the process of ordering and interpreting a genetic test.
- The consumer should be fully informed regarding what the test can and cannot say about his or her health.
- The scientific evidence on which a test is based should be clearly stated.
- The clinical testing laboratory must be accredited by CLIA, the State and/or other applicable accrediting agencies.
- Privacy concerns must be addressed.
Visit http://www.acmg.net for the complete ACMG Policy Statement.
Only a few patients have been tested so far, but the prospect of restoring sight to patients with a specific genetic condition is being tested. You can see the Good Morning America presentation and read news articles about the procedure here.
The inherited retinal disease is called leber congenital amaurosis; it prevents the retina from processing light.
The treatment is very quick--surgery lasting only an hour--but the preparation for the ability to transfer the key gene into the retina has taken over 10 years. It was especially interesting to me to hear that the profiled patient came to the States for her treatment because she couldn't find treatment where she lived. According to an excellent and informative site that gives information on gene therapy:
In an article in April 24's San Jose Mercury News, author Steve Johnson reports that "New York authorities are scrutinizing at least two Bay Area [California] companies offering consumers genetic tests, and California health officials have at least six gene-testing companies under investigation."
At issue in New York are regulations that require a clinical laboratory permit for specimens. Here are some more details:
Rushing to leave the house yesterday for an update on public responses to the biobank project being considered by the NIH, I had to leave the final voting to be captured on my DVR. Even at that time, it was obvious that the Senate was going to overwhelmingly approve passage of the Genetic Information Nondiscrimination Act.
It was interesting after that to hear comments:
"We helped get that done," from Kathy Hudson, head of the Genetics Public Policy Center.
"Thank you, everyone, for your tremendous efforts," from Sharon Terry, head of the Genetic Alliance.