A trisomy for 10q24--qter from a familial translocation; t(4;10) (q33; q24) in both grandparents.

A trisomy for 10q24--qter was found in a male infant. The clinical findings of the propositus were similar to those reported by other investigators. Both paternal grandparents are close relatives, and show the same balanced translocation, t(4; 10) (q33; q24). Their reporductive history reflected an extremely severe genetic imbalance. Four out of five children died in early infancy. The only living offspring is the father of the proband who has the balanced translocation.