Family-Based Interpretation of a Prenatally Detected 15q11.2 Duplication

Chromosome region 15q11-q13 is prone to structural rearrangements and contains imprinted genes associated with several neurodevelopmental syndromes. In this report, we present the case of a 518 kb duplication in 15q11.2, identified prenatally through array comparative genomic hybridization. Parental testing revealed that the duplication was paternally inherited and originated from the asymptomatic paternal grandmother. The duplicated region harbored the OMIM genes TUBGCP5, CYFIP1, NIPA1, and NIPA2, all of which presented biallelic expression and were not subjected to genomic imprinting. Given the benign familial inheritance and lack of clinical features in the father and the paternal grandmother, the duplication was considered likely to have benign significance. A healthy female newborn was delivered at term.