BCAP31 Mutation Causing a Syndrome of Congenital Dystonia, Facial Dysorphism and Central Hypomyelination Discovered Using Exome Sequencing

Early-onset dystonia is not encountered very frequently in adult movement disorders and child neurology clinics. A significant proportion of early-onset dystonia cases are estimated to be genetic, such as dopa-responsive dystonias (DYT1 and DYT6); however, some cases may have a treatable inborn error of metabolism, such as organic acidurias, glucose transporter 1 deficiency, Wilson’s disease, disorders of iron accumulation (e.g., PKAN), Niemann Pick C, and DYT5. Choosing the appropriate diagnostic test for these patients can be challenging and expensive. Next-generation sequencing techniques, such as whole-genome sequencing, whole-exome sequencing, or sequencing panels targeting specific disease-causing genes, have improved our diagnostic capabilities significantly and allow us to analyze massive number of genes simultaneously. Here, we report on two cases of congenital dystonia and central hypomyelination discovered by whole-exome sequencing.