Atelosteogenesis, type II is a severe disorder of cartilage and bone development. It is inherited in an autosomal recessive pattern and is extremely rare, infants with the disorder are usually stillborn, those that that survive birth die shortly after birth from respiratory failure. Infants born with this condition have very short arms and legs, a narrow chest, and a prominent, rounded abdomen. This disorder is also characterized by an opening in the roof of the mouth (cleft palate), distinctive facial features, an inward- and downward-turning foot (clubfoot), and unusually positioned thumbs (hitchhiker thumbs). The signs and symptoms of atelosteogenesis, type 2 are similar to those of another skeletal disorder called diastrophic dysplasia. Atelosteogenesis, type 2 tends to be more severe, however. Atelosteogenesis, type 2 is one of a spectrum of skeletal disorders caused by mutations in the SLC26A2 gene. The protein made by this gene is essential for the normal development of cartilage and for its conversion to bone. Mutations in the SLC26A2 gene disrupt the structure of developing cartilage, preventing bones from forming properly and resulting in the skeletal problems characteristic of atelosteogenesis, type 2. This condition is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell must be altered for a person to be affected by the disorder. Most often, the parents of a child with an autosomal recessive disorder are not affected but are carriers of one copy of the altered gene. This article incorporates public domain text from The U.S. National Library of Medicine
