Proximal 15q11.2 Microduplication: A Case Report of Variable Expressivity

Abstract

The four highly conserved and non- imprinted genes (NIPA1, NIPA2, CYFIP1 and TUBGCP5) are located on the proximal 15q in the region between BP1 and BP2 which spans approximately 500 kb. Here, we report on a paternally inherited 15q11.2 breakpoint 1-2 microduplication carrier with epilepsy, near-normal neurodevelopment, mild intellectual disability and speech delay. The father had a normal phenotype, suggesting the variable expressivity. Proximal 15q breakpoint 1-2 region copy number variants may not warrant a clinical outcome since the phenotypic variability and low penetrance. We believe that greater understanding of the possible underlying molecular, genetic, and environmental modifying factors of the copy number variants in this susceptibility locus will aid in our clinical approach.