HDAC6 and Macrocephaly: Moreover, mutations in the 3′ untranslated regions (UTR) of HDAC6, which encodes the class IIB KDAC enzyme, suppress miR433-mediated posttranscriptional regulation and cause overexpression of HDAC6, resulting in chondrodysplasia with platyspondyly, distinctive brachydactyly, hydrocephaly, and microphtalmia syndrome (OMIM 300863), which exhibits, among other symptoms, hydrocephaly and macrocephaly [138], [139].