Genes Tell

People always say “my son is a big boy, because I am tall”. Parents taken credited for this before any scientific evident were discovered. Have you ever thought about why your kids are tall, why they look like you and why they think and behave like you? A recently published paper (Yang et al. 2010) proved that parents indeed responsible for their children’s height. The paper showed that the large part of height is determined by the genes, which are the “life code” given by our parents and will also pass to our children. So, now you can confidently and soundly to say that your children are tall because of you. Although some “outside” conditions like what the children eat, whether they exercise enough, whether they sleep enough also decide their heights, the effects of these “outside” conditions are not as large enough as gene. As showed in the paper, 45% of the height can be explained by genetic factors alone based on current findings. This means that, other factors together will contribute to the remaining 55% at best. Actually, this paper is not the first one to uncover the genes’ function on people’s height. Another paper published in 2009 showed that 21% of the height can be explained by genes. So is height the only thing genes can decide? Well, genes are much more powerful than this. Another example: double-fold eyelids. Scientists found that double-fold eyelids are also determined by the genes. If both parents are double-fold eyelids, the chance that their children are also double-fold eyelids are more than 75%. And if both parents are single-fold eyelids, their children will almost surely be single-fold eyelids. Genes are magic, right?  

What is even more magic is that genes do not only tell us about our appearances, but can also tell us our health conditions. When you visit a physician for a disease, let’s say type 2 diabetes, you might be asked about whether you have family history of type 2 diabetes. So, why are your grandparents or your great grandparents’ health condition related to you? This is also because of gene. Huntington disease, normally onset at the middle age with syndromes such as lower IQ and psychology disorders, is another genetic disease. If either parent has Huntington disease, the children will have 50% chances to get the disease. If both parents have Huntington disease, their children will have 100% chances to get the disease. According to the Center for Disease and Control, genes are related with nine of ten leading cause of death in the US. Imagine, if we can find which genes cause which disease and we can change that gene, we will be a group of healthier and merrier people. And trust me, this is not a fiction. There are already 1212 genes found to be associated with 120 traits according to National Institute of Health. Don’t regard these researches as time-consuming, expensive and unrealistic ones. Battelle Technology Partnership Practice did a study and shows that “for every 1 dollar invested by the U.S. government, the Human Genome Project’s impact has resulted in the return of $141 to the U.S.”. In the following decades, we will witness the power of genes. As what is predicted by Eric Green, the director of National Human Genome Research Institute “There is little doubt that the predicted benefits of the Human Genome Project, originally envisioned more than 25 years ago, are beginning to arrive — both economically and clinically. “    

Yang et al., Common SNPs explain a large proportion of the heritability for human height, Nature Genetics, 42, 565-569, 2010

http://www.genome.gov/27527308

About Yunxuan Jiang: Yunxuan is a first year PhD student at Emory University. Biostatistics is her major and interest. Her old favorite thing was lying on the couch, doing nothing and pretending she was dead. Started from this year, she decided to say goodbye to her couch and enjoy the fantastic world. She is learning badminton and yoga now. And she is going to visit California for the first time in her life this winter!