What roles do non-coding DNA play in genetic diseases & syndromes?
Good question, thanks. Currently, when we sequence all of the protein-coding regions of a patient (a.k.a. an "exome"), we find a causative mutation about 30% of the time. Our incomplete knowledge of protein biology accounts for some of the rest, but I'm willing to bet that a good portion of that 70% of unsolved cases is due to changes in the non-coding DNA. The trouble is that we don't have nearly as good of methods yet to prove causality of those non-coding variants.
- Answer provided by Dr. Paul Gordon
If there is about 40,000 genes in the human body, why is there a large amount of non-coding genes that greatly outnumber the coding genes in our DNA?
The function of this "dark DNA" is an ongoing area of research. Because of the existence of retroviruses and transposable elements (TEs), some think the junk DNA serves as a scaffold for our genes and provides a place where TEs can insert themselves without disrupting the function of our genes.
- Answer provided by Dr. Robert Hanner