Sunday, April 27, 2008

Students' Questions from "National DNA Day"

Friday was National DNA Day. And like National Child Day, DNA Day is something I can get really excited about as the message of such a day (i.e. celebrate human curiosity, ingenuity and science!) is vital for a healthy and humane polity.

The NHGRI web site has a list of hundreds and hundreds of questions students sent in all over the U.S. on DNA Day. And reading over the very long list of questions raised by these bright students was very encouraging. Here is a sample:

Q: Kannapolis Middle School (8th grade student): How many different countries worked on the human genome project?
A: Phyllis Frosst, Ph.D.: From its inception, the HGP has been an international effort. The United States has made the largest investment, but important contributions have come from many countries, including Britain, France, Germany, Japan, China, and Canada.

Q: Booth Middle School (7th grade teacher): How is DNA being used in the field of evolutionary biology?
A: Elliott Margulies, Ph.D.: Since DNA is found in every living organism, we can compare DNA from different species to see which bits are similar and which bits are different. When sequences remain similar throughout millions of years of evolution, we can deduce that the sequence is likely functional. In fact, "comparative genomics" is a major way we can determine the functions encoded genomic sequences.

Q: Holy Family Catholic High School (9th grade student): Why do people have red hair?
A: Arjun Prasad, B.S.: The genetics of hair color in humans is not very well understood, but a lot of work has been done in the hair color of horses because breeders have been very interested in breeding certain hair colors of horses. Horse hair color is controlled by a large number of genes, only some of which have been worked out. Some of the genes that control horse coat color are genes that code for the actual colored proteins behind horse coat color, and some of them are differences in when/where those genes are turned on or off to make white legs, or spots for example.

Q: John C. Fremont High School (10th grade student): Can parents choose the sex of their children?
A: Don Hadley, M.S., C.G.C.: There are ways that have been suggested to increase the chances of having a boy or girl, however, they are NOT fully reliable. This is an issue that raises many ethical and social issues of concern. Should we, as a society, be picking our children's characteristics and traits? There's no easy answer to this and it will require a lot of careful consideration.

Q: Rock Canyon High School (11th grade student): How difficult is it to turn on or turn off a persons genes once they are already an adult? (MS)
A: Greg Feero, M.D., Ph.D.: It is not, your genes turn on and off many times a day in each of your cells. Many factors affect this including your diet, your physical activity and and the medications you might take....

Q: Dennis (10th grade student): Do chimpanzees have DNA similar to humans?
A: Carla Easter, Ph.D.: Humans and chimpanzees are about 95% genetically identical.

Q: Susan (n/a grade other): Have you discovered the genes involved in depression or bipolar disorder?Once the genes are identified, how difficult is it to come up with drugs that over come the genetic deficiency?
A: Greg Feero, M.D., Ph.D.: In the last year there have been a large number of studies relating gene discoveries relevant to mental health conditions. These have come about because of a new approach to gene discovery called "genome-wide association studies". Each of these new markers provides potential new approaches to develop therapies. Discovery of new drugs is usually a long and challenging process, but with new genes in hand many scientists are excited that new therapies will come in the next few decades. For more on genome-wide association studies see the catalog of genome wide association studies on

Q: Francis Howell North (11th grade student): Which genetic diseases are increasing in frequency in humans (in the past few generations)?
A: Greg Feero, M.D., Ph.D.: In the United States diseases like diabetes and heart disease are increasing in the population. These diseases result for interactions between environmental factors and a large number of genetic factors. The interesting question is why. It seems less likely that the genetic factors are becoming more common and much more likely that those disorders are becoming more common because the environmental factors (like lack of exercise and poor diet) are becoming more common.

Q: Montgomery College (Higher Education grade student): What proportion of the human genome is thought not to have a function (truly "junk" DNA)?
A: Elliott Margulies, Ph.D.: A long time ago, some people thought that all DNA that didn't code for genes was "junk". We now know that non-coding DNA plays a very important role in regulating how genes are turned on and off. We're still trying to figure out what all this non-coding DNA does, and my bet is that little to none is "junk" (though admittedly that gives me job security since my lab studies non-coding DNA!)

Q: Westview High School (9th grade student): What are major hurdles scientists are still faced with that they still have to overcome?
A: Arjun Prasad, B.S.: One fun thing about being a scientist is that the more we discover the more we realize all that we don't know. We have completed the sequencing of the human genome, but we are now trying to understand what it all means. A big hurdle now is to understand the genetic differences between people that are responsible for inheritable differences in disease susceptibility. We know that some people can smoke their whole lives and never get lung cancer, why is that? The hope is that by figuring out the genes that increase risks for disease we can also figure out how to prevent them from getting the disease in the first place and treat those diseases more effectively.

Q: Michael pointer (9th grade student): will learning this stuff actually help us in the future?
A: Alan Guttmacher, M.D.: I guess it depends what stuff you are learning - although almost anything I have learned has eventually proved useful sometime. If you mean this stuff about genetics, the answer is definitely "yes." In your lifetime, much of health care will rely on patients being knowledgeable enough about genetics to work with their doctors to devise personalized prevention strategies to avoid many of the common diseases that us old folks have fallen victim to...

Q: Shikellamy High School (10th grade student): Have you ever said "I don't know" to a genetic question?
A: Alan Guttmacher, M.D.: YES!!!!! In both research and in medicine, it is incredibly important to know when you don't know something, and to be honest about that fact with both yourself and others. In fact, much of the fun of research is to answer questions that have never had an answer before.

Q: Maple Shade High School (10th grade student): What causes bad vision?
A: Don Hadley, M.S., C.G.C.: There are a number of factors that can cause a person to have poor vision. A person's genetic make-up can be one of the factors that influence our ability to see. Many genes are being identified that influence our visual abilities on different levels, development, clarity, ability to see far and near, etc. However, there are other "non-genetic" factors that can be involved in our ability to see such as environmental factors that effect the development of the eye while the baby is growing in the mother's womb or exposures to harsh chemicals that cause destruction to functioning of the eye. Great question. I encourage you to look into this further

Q: Joe Nva Academy (9th grade student): what is the worst possible disease to get if your genomes are messed up
A: Alan Guttmacher, M.D.: There is no single answer to this question. It depends upon who you ask and what things they care about. If someone cares most about having a long life, then any of a number of diseases that often provide fateful very early in life would be the answer. If it was avoiding physical pain that was most important, that would dictate another list of diseases. If it was having a condition that leads to loss of intelligence and control over one's body, yet another group of conditions would come to mind. If it was diseases that lead to physical disfigurement that were most feared, that would be another group. So, it all depenfds upon who you ask, and what they care most about...