Mutations in ADAMTS19, the sister protease of ADAMTS17, cause non-syndromic heart valve disease (dysplasia of the aortic valve in two patients and sub-aortic stenosis in another patient; Pulmonary valve stenosis in all four patients; Mitral valve dysplasia in one patient and Tricuspid valve grade I regurgitation in one patient; bicuspid aortic valve in two patients). The gene discussed is ADAMTS19; the disease is pulmonary valve stenosis.