A family with a high risk of segregation for an autosomal unbalanced reciprocal translocation.

A family with autosomal reciprocal translocation t(4;13) (q25;a31) with a sibship comprising 2 children with unbalanced karyotypes, der(13) partial trisomy 4q, 1 child with the balanced translocation, and 2 abortions were studied. The segregation risk of unbalanced derivation in reciprocal translocations is discussed. The clinical picture of the 2 children with partial trisomy 4q is compared with similar cases.