17p13.3 Microdeletion: Insights on Genotype-Phenotype Correlation.

Microdeletions in the chromosomal region 17p13.3 are associated with neuronal migration disorders, and PAFAB1H1 is the main gene involved. The largest genomic imbalances, including the YWHAE and CRK genes, cause more severe structural abnormalities of the brain and other associated dysmorphic features. Here, we describe a 3-year-old boy with a microdeletion in 17p13.3 presenting with minor facial dysmorphisms, a cleft palate, neurodevelopmental delay, and behavioral disorder with no structural malformation of the brain. The patient was evaluated by a clinician using a standard protocol. Laboratory investigation included GTG-banding, whole-genome AGH, and array-CGH. Whole-genome AGH and array-CGH analysis identified an estimated 2.1-Mb deletion in the 17p13.3 region showing haploinsufficiency of the YWHAE, CRK, H1C1, and OVCA1 genes and no deletion of PAFAH1B1. The complex gene interaction on brain development and function is illustrated in the genotype-phenotype correlation described here. This report reinforces the importance of the 17p13.3 region in developmental abnormalities and highlights the weak implication of the HIC1 and OVCA1 genes in palatogenesis.