Sex chromosomal and autosomal aneuploidy in the fragile X syndrome.

To date, the evidence to establish the association between aneuploidy and fragile sites, albeit thought-provoking, has been anecdotal and for the most part hypothetical. Studies with larger sample size and the use of RFLP analyses to establish parental origin of aneuploid states will undoubtedly resolve the issue. If an association between aneuploidy and fragile X and fragile site families is proved, this would have substantial impact on the counseling and management of these families. A confirmed association would direct investigators to determine common underlying biological factors leading to meiotic and mitotic nondisjunction.