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Omodysplasia 1 (OMOD1; MIM 258315) is a congenital, autosomal recessive rhizomelic dysplasia.  It is characterized by proximal shortening and distal tapering of the humeri and femora. Some other skeletal findings may include limited flexion or extension of the elbows and knees, hypoplasia of the distal humeri, radioulnar diastasis, anterior lateral dislocation of the radial head, hypoplastic everted lateral condyle, proximal club shaped femurs, short and thick tibiae and fibulae.  Facial anomalies include frontal bossing, small nose with a depressed nasal bridge, flat face, micrognathia, and long philtrum. Some individuals have been described with congenital heart defects, cryptorchidism, umbilical hernia, and cognitive delay. Autosomal recessive omodysplasia is caused by loss of function mutations in the glypican 6 gene (GPC6). Autosomal dominant omodysplasia is caused by loss of function mutations in the FZD2 gene. The phenotype of the autosomal dominant form overlaps with OMOD1, but is generally less severe. The autosomal dominant form is mainly characterized by short upper limbs, short metacarpals, and facial dysmorphism. Short first metacarpals is not a feature of OMOD1.