Nationwide survey of Baller‑Gerold syndrome in Japanese population

: Baller-Gerold syndrome (BGS) is a rare autosomal genetic disorder characterized by radial aplasia/hypoplasia and craniosynostosis. The causative gene for BGS encodes RECQL4, which belongs to the RecQ helicase family. To understand BGS patients in Japan, a nationwide survey was conducted, which identified 2 families and 3 patients affected by the syndrome. All the three patients showed radial defects and craniosynostosis. In one patient who showed a dislocated joint of the hip and flexion contracture of both the elbow joints and wrists at birth, a homozygous large deletion in the RECQL4 gene was identified. This is the first reported case of BGS in Japan caused by RECQL4 gene mutation.