Proximal trisomy 13. A family with balanced reciprocal translocation t(8;13) in seven members and Robertsonian translocation t(13;14) in three members.

The cytogenetic analysis of a 12-year-old retarded boy revealed a partial proximal trisomy 13, resulting from a maternal translocation t(8;13). A familial study shows this translocation in seven persons and also a Robertsonian translocation t(13q;14q) in three sons of a t(8;13) father. A review of partial proximal trisomies 13 shows a variability in the phenotypic expression.