Top Ten Most Interesting Genetic Findings of 2012
23andMe has released its third annual list of the ten most interesting and significant genetic findings in 2012 as part of the company's ongoing efforts to understand the role of genetics in personal health and human development.
"It's a very exciting time in the world of genetics. Technology improvements and big datasets are making incredible advancements possible," said Anne Wojcicki , co-founder and CEO of 23andMe. "Our own researchers at 23andMe continue to contribute important findings, from understanding the importance of genetics used in conjunction with family health history to assess personal health, to identifying new genetic associations for blood disorders called myeloproliferative neoplasms."
23andMe customers have the opportunity to learn about how their genetics can influence their individual health traits, risk for developing certain diseases and conditions, reactions to a variety of medications, conditions that may be inherited, and ancestry. Throughout the year, 23andMe monitors the highest quality research published in scientific journals for studies that provide exciting glimpses into these areas. The company provides information on these developments to its customers through continual updates to their Health and Traits reports, as well as "SNPwatch" postings to the 23andMe Blog.
REFLECTING ON 2012 The Top Ten Genetic Findings of 2012 were selected by the researchers of 23andMe drawn from research presented throughout the year on the 23andMe Blog and research published in peer-reviewed journals.
"We often find unexpected genetic associations derived from 23andMe's own crowd-sourced research," said Shirley Wu , PhD, 23andMe science content manager who oversaw the selection process. "By answering simple online surveys, our community has provided more than 70 million phenotypic data points in addition to their genetic information for research. With nearly 90 percent of our more than 180,000 customers participating in our research, we have a powerful data set that enables us to make important discoveries."
1. A Genetic Variant Protective Against Alzheimer's Disease
A very rare variant was found to be associated with about five times lower odds of Alzheimer's. While this rare variant (the T version of rs63750847 — also known as the A673T variant in the APP gene) is only found in about one in 10,000 people of European descent, the research adds more insight into the development of the disease. Many mutations in the APP gene actually cause Alzheimer's through an overproduction of beta amyloid protein in the brain (a hallmark of Alzheimer's), but the protective variant appears to do the opposite, according to the study. New drugs built on this finding could help protect against Alzheimer's, or even the mental ravages of normal aging. 23andMe does offer customers reports on their own Alzheimer's risk based on the more common APOE variant, as well as a report on this protective APP variant.
2. ENCODE Project Creates an Map of the Uncharted Areas of the Genome
Much of the work in genetics has been focused on the areas in our DNA that code for proteins, but this is a very small part — just one percent — of our genome. The ENCODE project, which has enlisted more than 400 scientists over several years, is attempting to map the rest of it, the so called "dark matter" of the genome. What they've created is the foundation for a sort of encyclopedia of the functions of many of these uncharted areas of the genome. It's a resource with incredible potential that will be used by many scientists in the years to come.
3. Noninvasive Prenatal Sequencing
Two separate research groups reported within weeks of each other that they had successfully sequenced a human fetus using non-invasive methods. The breakthrough offers an opportunity for earlier prenatal screening than currently offered with amniocentesis or chorionic villous sampling (CVS) without the same risks for potentially harming a developing fetus.
4. New Insights into Group of Rare Blood Disorders Known as MPNs
In less than a year, 23andMe recruited a 1,000-person cohort with a group of rare blood disorders known as myeloproliferative neoplasms, or MPNs. Within months of reaching that goal we began reporting out new findings. Among them were replications of known genetic associations with the disease as well as new ones including an association between these conditions and variants in the TERT and ATM genes.
5. New Insights into the Human Origins and Evolution
Several different studies highlight ongoing research on our early ancestors and the evolution of modern humans. Beyond the compelling tale of our early ancestors, the journey out of Africa and the intermixing with Neanderthals and Denisovans, the new research also gives us insight into the significance of rare genetic variants which are vastly more numerous than common variants and tend to have stronger influence on disease risk.
6. Family Medical History and Genetics Best Used Together to Predict Disease
23andMe developed a model demonstrating that both family history and genetic tests have strengths in predicting disease risks, but together they provide the best predictor for disease.
7. Older Dads' Biological Clocks
For a long time prospective fathers could while away the years without much worry about when to have kids, while prospective moms were constantly checking their ticking biological clocks. A study may turn the tables a bit, pushing men to think a little more about how long they wait to start a family. The study says that as men grow older the number of de novo mutations they pass onto their children increases, and preliminary studies suggest that the more de novo mutations passed onto a child the higher the risk that child could develop certain types of conditions, such as autism and schizophrenia. That said, becoming a dad can actually be good for you. There's evidence linking fatherhood to healthier hearts.
8. Breast Size Matters, But Not How You Think
Researchers at 23andMe found that genetic factors influence breast size and that in turn these factors are connected to the genetics of breast cancer.
9. New Treatment for Cystic Fibrosis
Early in 2012 the FDA approved ivacaftor (Kalydeco) as a new treatment for cystic fibrosis, one of the most common recessively-inherited diseases. The drug developed by Vertex Pharmaceuticals Inc. is the first treatment that targets one of the underlying causes of cystic fibrosis — a specific genetic mutation — rather than its symptoms.
10. Autism Study Reveals No Genetic Associations
It may be strange to point to a study that finds no genetic associations, but sometimes an absence of evidence can hint toward new routes of study. Cases of autism spectrum disorder (ASD), which runs the gamut from the relatively mild Asperger syndrome with mild social impairments to full-fledged autism characterized by repetitive behaviors and severe communication and social-interaction difficulties, had become increasingly common in the US. Why that is, is not so easy to discern. The lack of an association doesn't mean that genetics isn't important. In fact twin studies suggest that autism is at least moderately heritable, but it may be that genetic variations play a smaller role than rare mutations or copy number variation in the risk of a person developing autism. According to Autism Speaks Senior Vice President, Scientific Affairs Andy Shih, PhD, currently available clinical applications, including karyotype and microarrays allow the detection of genetic aberrations in about 20 percent of the cases of ASD.