A boy with proximal trisomy 15 and a male foetus with distal trisomy 15 due to a familial 13p;15q translocation.

A familial 13p;15q translocation was ascertained through a mentally retarded boy with a proximal trisomy 15 syndrome. His mother, who was a balanced 13p;15q carrier, had in addition a legal abortion after 22 weeks of gestation because of a prenatal diagnosis of distal trisomy 15 in a male foetus. Her mother and two sisters, who were balanced carriers, all had children with either a normal karyotype or a balanced translocation or had had pregnancies resulting in an early spontaneous abortion.