born with extra chromosome?

Possible Answer:
In some cases, the addition of an extra Y-chromosome results from nondisjunction during cell division during a post-zygotic mitosis in early embryonic development. ... born in Copenhagen from 1944–1947 for XXY and XYY karyotypes, ... - read more

Possible Answer:
My brother was born with an extra chromosome and he is 38 and I am 40. He and I were flown out to the National Jewish Genetic Center for many years during our childhood. He is perfectly normal. - read more

Please vote if the answer you were given helped you or not, thats the best way to improve our algorithm. You can also submit an answer or check other resources.