Biallelic HMGXB4 loss-of-function variant causes intellectual disability, developmental delay, and dysmorphic features

HMGXB4 (additionally known as HMG2L1) is a non-histone DNA-binding protein that contains a single HMG-box domain. HMGXB4 was originally described in Xenopus where it was seen to negatively regulate the Wnt/β-catenin signaling pathway.