|MadSci Network: Genetics|
Dear Barbara, That is a really interesting question. I'm not an expert on these disorders but I have given a lecture on the subject and found in my research that people with XXY are more prone to having typically 'female' diseases such as osteoperosis and breast cancer. That doesn't answer your question though. Some XXY males are a mosaic of tissues with some being XY and some being XXY and this could effect the concentration of X chromosome protien products in areas with only XY - perhaps this could lead to localised normal susceptibility to X-linked disorders or protection from in XXY areas but this is just my own speculation. Females are XX but X inactivation doesn't stop them from having less chance of getting X-linked disorders so presumable XXY males would also benefit from the extra X chromosome in this way. I've read that very few studies have been performed on adult XXY males so perhaps the answer just isn't out there yet or it may be that it is difficult to distinguish between symptoms due to the XXY phenotype (e.g. some have mental retardation)and symptoms which would be due to X-linked disorders. If you want further information then a good site is http://www.nih.gov/health/chip/nichd/klinefelter/#xhealth My advice would be go search the websites dedicated to this disorder and contact the person who made the best site. Yvonne
Try the links in the MadSci Library for more information on Genetics.