Orofaciodigital syndrome 1 (OFD1), also called orofaciodigital syndrome type 1, is a condition that affects the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes). This condition also causes polycystic kidney disease. Orofaciodigital syndrome 1 is caused by a change in a gene called OFD1 which appears to play an important role in the early development of many parts of the body including the brain, face, limbs, and kidneys. The syndrome is inherited in an X-linked dominant pattern. The diagnosis of OFD1 is sometimes made at birth, but it may be suspected only after polycystic kidney disease is found in later childhood or adulthood. OFD1 is the most common form of orofaciodigital syndrome and differs from the other types mainly by its association with polycystic kidney disease.