MICrocephaly, Disproportionate Pontine and Cerebellar Hypoplasia Syndrome: A Clinico-radiologic Phenotype Linked to Calcium/calmodulin-dependent Serine Protein Kinase Gene Mutation

MICrocephaly, disproportionate pontine and cerebellar hypoplasia (MICPCH) syndrome, a rare X-linked disorder, generally seen in girls, is characterized by neurodevelopmental delay, microcephaly, and disproportionate pontine and cerebellar hypoplasia. It is caused by inactivating calcium/calmodulin-dependent serine protein kinase (CASK) gene mutations. We report a 2-year-old girl with severe neurodevelopmental delay, microcephaly, minimal pontine hypoplasia, cerebellar hypoplasia, and normal looking corpus callosum, with whom the conventional cytogenetic studies turned out to be normal, and an array-comparative genomic hybridization (a-CGH) analysis showed CASK gene duplication at Xp11.4. Our case highlights the importance of using clinico-radiologic phenotype to guide genetic investigation and it also confirms the role of a-CGH analysis in establishing the genetic diagnosis of MICPCH syndrome, when conventional cytogenetic studies are inconclusive.