Several neural crest regulatory molecules are known to cause ear/kidney syndromes with variable expression of both ear and kidney phenotypes (e.g., EYA1, SIX1, SIX5, CHD7, MASP1, TBX1), involved in BOR/BO syndrome, CHARGE syndrome, 3MC syndrome and DiGeorge syndrome [5,47]. The gene discussed is MASP1; the disease is 3MC syndrome.