Two of these disorders – mandibulofacial dysostosis Guion-Almeida type (MFDGA) and Burn-McKeown syndrome (BMKS) – are caused by variants in U5 snRNP proteins, EFTUD2 and TXNL4A, respectively. The gene discussed is EFTUD2; the disease is Choanal atresia-deafness-cardiac defects-dysmorphism syndrome.