Novel chromosomal translocation t(11;9)(p15;p23) involving deletion and duplication of 9p in a girl associated with autism and mental retardation.

We describe a 5-year-old girl presented with autism and mental retardation features. Conventional karyotyping revealed a novel unidirectional translocation t(11;9)(p15;p23). HumanCytoSNP-12 Chip analysis identified a 13 Mb deletion from 9p24.3 to 9p23 and a 12.5Mb duplication from 9p23 to 9p21.2. The karyotype was described as 45,XX,psu dic(11; 9)(p15;p23), which was reported for the first time here. The deleted region, extending from 9p24.3 to 9p23, overlaps with the candidate region for monosomy 9p syndrome and contains a potential autism spectrum disorders (ASD) locus. The duplication region extending from 9p23 to 9p21.2 was previously identified as a critical region for the 9p duplication syndrome. These results suggested that the apparently balanced de novo translocations could produce cryptic deletions or duplications, and the precise mapping of the abnormal area may improve clinical management.