Amongst these OTUD5 substrates are ARID1A/B, HDAC2, and HCF1, mutations of which underlie different developmental disorders (Coffin–Siris and Cornelia de Lange syndromes [227, 228], X-linked mental retardation 3 [229]) that exhibit considerable phenotypic overlap with LINKED patients. Here, HDAC2 is linked to methylmalonic acidemia with homocystinuria, type cblX.