Parental age and the risk of genetic defects in the offspring

Despite numerous studies, the age-related risk of genetic defects in the offspring remains poorly understood. It is clear that the frequency at birth of some mendelian disorders is related to advanced paternal age, but this relationship is heterogeneous and varies from one disorder to another. Similarly, it has been proposed that among commonly observed birth defects, a subgroup of cases may be due to new unrecognized dominant mutations of paternal origin. Finally, despite many years of enquiry, increasing maternal age remains the only incontrovertible factor associated with human aneuploidy. [Copyright &y& Elsevier]