Partial 5p monosomy or trisomy in 11 patients from a family with a t(5;15)(p13.3;p12) translocation.

A family with six alive patients with partial monosomy 5p and five with partial trisomy 5p due to a t(5;15)(p13.3;p12) translocation is reported. The translocation was present in four generations with eight balanced carriers. This is the first molecular-cytogenetic and clinical study with both syndromes present in the same family. Using fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) probes, the breakpoint was mapped to 5p13.3, in the interval corresponding to the BAC clone RP11-1079N14, thereof resulting a 5pter-5p13.3 deletion or duplication of approximately 32 Mb. These chromosome imbalances can be considered pure, since the other imbalance produced involving chromosome 15p has no phenotypic effect. The presence of several individuals with 5p monosomy and 5p trisomy in the same family is valuable for a better delineation of both syndromes.