Familial Aggregation of Chiari Malformation: Presentation, Pedigree, and Review of the Literature.

This article reports the largest familial aggregation of Chiari malformation in a single family to date as reported in the literature. This study is a retrospective case series of a family of whom five individuals have a confirmed case of Chiari malformation and three additional individuals have Chiari signs and symptoms. This contribution further supports the implication of genetics in the transmission of Chiari malformation. The family reported in this study also has a significant incidence of Ehlers-Danlos. Three sisters, including a set of twins, presented with confirmed cases of Chiari malformation and four of the five children of the twin sisters presented with confirmed or suspected Chiari malformation. Of note, the non-twin sister has three children who are unaffected. This report provides further evidence for a shared loci between the Chiari malformation and Ehlers-Danlos.