Biallelic deleterious variants resulting in loss of function of MGP cause Keutel syndrome (KS) (OMIM #245150), an autosomal recessive disorder characterized by abnormal cartilage and vascular tissue calcification, midfacial hypoplasia, peripheral pulmonary artery stenosis, brachytelephalangism, mild developmental delay and hearing loss8–11. This evidence concerns the gene MGP and Keutel syndrome.