The Largest-Scale Genetic Study of Chinese People to Date

Data from noninvasive prenatal testing for fetal trisomy (condition that can cause Down Syndrome) was used by scientists in order to determine and predict past and present characteristics of people in China. The testing analyzes free floating bits of fetal DNA in the mother's blood. This test occurs in China and costs only $100 compared to high quality, whole genome sequencing which costs $1,000 per person. Using the cheaper testing method came with a cost by covering only 10 percent or less of the person's genome, while the more thorough test covered 80 percent or more. Designing custom software and using heavy computations and statistics made up for the leftover analysis.

The resulting data represented nearly every Chinese province which eclipsed many genome-wide studies which include only tens of thousands of participants making this the largest scale genetic study of Chinese people. A total of 141,431 individuals participated. Some information they reported included data showing that more northern than southern Chinese populations contain a mutation of FADS2, a gene involved in metabolizing fatty acids, which indicates a diet richer in animal content. This helps explain the type of food that they eat in their area based on their resources and climate. Also, DNA that was not aligned to the human genome against a database of viral sequences were found in order to diagnose viruses, most commonly identifying hepatitis B and other viruses that can affect pregnancies. In addition, 48 gene variants associated with height and 13 with body mass index were collected by analyzing the height and body mass index of their samples. Doing this reveals associations between genes and specific traits through noninvasive pregnancy testing. This data collection on evaluating prenatal testing is still moving forward today for more than 3.5 million Chinese people.

This type of research seems very promising and intriguing to me as they can continue this type of data analysis for other races, not just Chinese. Since I am Filipino, I'm hoping they can expand their data collection in the Philippines so I can learn more about genetic characteristics and their history. Each race should receive this type of testing which can lead to predictions in human traits of fetuses.

Prenatal tests for Down Syndrome

     Breakthroughs in new tests for prenatal screening allow for women to have more options.   New screenings are more accurate and less invasive.  They allow for screenings of any chromosomal abnormalities while avoiding the risks that amniocentesis imposes.  In the past, the decision to undergo an amniocentesis was based on risk due to the woman’s age and genetic history.  Many amnios were performed but not medically necessary, due to the lack of accurate information provided. The new advancements in screenings that are noninvasive and more accurate allow for women to make well-informed treatment decisions.

     

     The new screenings test the fetal DNA that is found in the mother’s blood.  These tests provide results that detect almost all cases of Down syndrome and result in a false positive result of less than 1% of all cases.  Which is significantly less than older tests.  Noninvasive test results that are positive require an amniocentesis to confirm the existence of Down syndrome.  

     This new noninvasive screening test leads to the possibility of treating a fetus with chromosomal abnormalities prior to birth.  Prenatal treatment such as this, would hopefully allow for the minimization of neurological effects caused by the detected disease.  The developments in prenatal testing and treatment are relatively new and still being tested.  Hopefully within the near future, availability for screening such as this will become more affordable.  It is exciting that such a breakthrough could allow for the discovery of treatments for genetic diseases prior to birth.

http://well.blogs.nytimes.com/2013/10/07/breakthroughs-in-prenatal-screening/?_r=0
http://health.nytimes.com/health/guides/test/amniocentesis/overview.html?inline=nyt-classifier