Supplementary Material for: Dandy-Walker Malformation in a girl with DDX3X-related intellectual disability

We report on a 4 years old female patient who presented with severe intellectual disability, autistic features, hyperlaxity of joints and progressive scoliosis. Whole exome sequencing identified a novel de novo missense variant (c.976C>T; p.Arg326Cys) in DDX3X. The girl was born with congenital diaphragmatic hernia a finding which had not previously been associated with variants in DDX3X. Her brain MRI showed hypogenesis of corpus callosum, ventriculomegaly, frontal and perisylvian polymicrogyria and hypoplastic pons in addition to Dandy-walker malformation. Our results confirmed the phenotype and genotype correlation of missense variants and the polymicrogyria. Moreover, it further expands the knowledge of the phenotypic and molecular features of DDX3X-related intellectual disability.