A rare case of a de novo dup(19q) associated with a mild phenotype.

Partial trisomy of the long arm of chromosome 19q is an uncommon aneusomy and has been reported in only 18 cases. Fourteen of these were the result of unbalanced translocations. Only four cases were the result of pure duplications. The phenotype described includes microcephaly, heart malformations, anomalies of the genitourinary tract or gastrointestinal system, and growth retardation. Developmental delay is common (table 1) and the prognosis usually poor owing to the severity of the anomalies. We present a child with a dir dup(19)(q13.1q13.3) de novo direct duplication. The origin of the extra material was confirmed by fluorescence in situ hybridisation (FISH) using a whole chromosome paint probe for chromosome 19. The patient’s phenotype is less severe than previously reported and possibly reflects the different rearrangement breakpoints and concomitant extent of duplication.