is a severe disorder that affects the development of the skeleton and reproductive system. This condition is often life-threatening in the newborn period. Affected individuals are typically born with bowing of the long bones in the legs and may also have bowing in the arms; short legs; dislocated hips; underdeveloped shoulder blades; bone abnormalities in the neck; feet that are abnormally rotated (club feet); external genitalia that do not look clearly male or clearly female (ambiguous genitalia); distinctive facial features (including a small chin, prominent eyes, flat face, a large head compared to their body size); a particular group of physical features, called Pierre-Robin sequence; and other abnormalities. It is caused by mutations in the SOX9 gene and is inherited in an autosomal dominant pattern, although most cases result from a new mutation in the affected individual. Treatment typically includes multiple surgeries to correct some of the above-mentioned abnormalities. When affected individuals have features of this disorder but do not have bowed limbs, they are said to have acampomelic campomelic dysplasia. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.