In support of an important role in development, heterozygous loss-of-function variants in HDAC4 have been reported to cause brachydactyly-mental retardation syndrome (BDMR [MIM: 600430]),13, 14, 15, 16 common features of which are brachydactyly type E, mild to moderate intellectual disability (ID), seizures, autism spectrum disorder, short stature, obesity, and facial dysmorphism. Here, HDAC4 is linked to 2q37 microdeletion syndrome.