Guest guest Posted June 29, 2007 Report Share Posted June 29, 2007 There are (at least) two possible explanations for those with CHARGE who are " negative " for CDH7 mutations: 1) There may be more than one gene that causes CHARGE. That is the case for many genetic conditions. Researchers are actively looking for other possible genes. 2) We just aren't smart enough to find all of the mutations in CHD7. Most of the mutations involve a single base pair (like a typo of just one letter). The CHD7 gene is huge: it has 5901 base pairs, just in the coding regions. There are 38 different coding regions, separated by non-coding regions. Finding a typo in that is hard (that's why it's so expensive). AND, for all we know, the non-coding regions may also be important. the recent report on scoliosis and CHD7 changes was a change in a non-coding region! [as far as we know, there is nothing else that " causes " CHARGE - nothing that happens during the pregnancy, for example] Go to the Genetics talks in California for more explanation! Meg Meg Hefner MS Genetic Counselor St. Louis, MO > > I was just wondering how to explain why some people born with CHARGE > syndrome are positive for the CHD7 and others not. In the case of the > ones that are not, what is the cause of CHARGE then? > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 29, 2007 Report Share Posted June 29, 2007 Thank you, Liz -- Re: genetic question There are (at least) two possible explanations for those with CHARGE who are " negative " for CDH7 mutations: 1) There may be more than one gene that causes CHARGE. That is the case for many genetic conditions. Researchers are actively looking for other possible genes. 2) We just aren't smart enough to find all of the mutations in CHD7. Most of the mutations involve a single base pair (like a typo of just one letter). The CHD7 gene is huge: it has 5901 base pairs, just in the coding regions. There are 38 different coding regions, separated by non-coding regions. Finding a typo in that is hard (that's why it's so expensive). AND, for all we know, the non-coding regions may also be important. the recent report on scoliosis and CHD7 changes was a change in a non-coding region! [as far as we know, there is nothing else that " causes " CHARGE - nothing that happens during the pregnancy, for example] Go to the Genetics talks in California for more explanation! Meg Meg Hefner MS Genetic Counselor St. Louis, MO > > I was just wondering how to explain why some people born with CHARGE > syndrome are positive for the CHD7 and others not. In the case of the > ones that are not, what is the cause of CHARGE then? > Quote Link to comment Share on other sites More sharing options...
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