2009 National DNA Day Online Chatroom Transcript
This is just one question from an archive of the National DNA Day Moderated Chat held in April 2009. The NHGRI Director and many genomics experts from across NHGRI took questions from students, teachers and the general public on topics ranging from basic genomic research, to the genetic basis of disease, to ethical questions about genetic privacy.
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How is height of an individual related to genetics? If a parent is short and another parent is tall, are the children an average of the two?
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Janice Berliner, M.S., C.G.C.:
I am a cancer genetic counselor, performing genetic risk assessment and counseling for cancer patients and those at risk for cancer.
It sort of seems this way, but height is a metric trait, which means that it is controlled by several genes that each contribute a certain amount. Let's say that height is controlled by 5 genes (I'm making up the number). We have 2 copies of every gene, one from each parent, so think of it as having a certain amount of points for each copy from each parent. The short parent is only going to give a small amount of points for each copy, and the tall parent is going to give more points, but not necessarily the same number of points for each copy to each child. Depending upon the number of points given, the child will grow to a certain height depending upon the total. Of course this can be influenced to some degree by nutrition, health and other external factors. |
| Trafalgar School For Girls (10th grade student) |
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