DOWN'S SYNDROME AT YOUNG MATERNAL AGES: CHROMOSOMAL AND FAMILY STUDIES.

Abstract

Forty-one patients with Down's syndrome born to women whose age at delivery wasless than 20 years have been studied. Three of the patients had chromosomal translocations; a parent of one of these had a similar chromosomal translocation. Three of the patients were mosaics. The data for the patients in this series were combined with data from the literature of patients with Down's syndrome whose mothers' ages at the time of delivery were less than 30 years. For women of less than 30 years of age, and without chromosome study, it is estimated that the maximum empiric risk of a second affected child as a result of a maternally transmitted D/G translocation is about 1 per cent. © 1965 The C. V. M..