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Weissenbacher-Zweymüller syndrome

Courtesy of Genetic Home Reference

What is Weissenbacher-Zweymüller syndrome?

Weissenbacher-Zweymüller syndrome is a condition that affects bone growth. It is characterized by skeletal abnormalities, hearing loss, and distinctive facial features. This condition has features that are similar to those of another skeletal disorder, otospondylomegaepiphyseal dysplasia (OSMED).

Infants born with Weissenbacher-Zweymüller syndrome are smaller than average because the bones in their arms and legs are unusually short. The thigh and upper arm bones are shaped like dumbbells, and the bones of the spine (vertebrae) may also be abnormally shaped. High-tone hearing loss occurs in some cases. Distinctive facial features include wide-set protruding eyes, a small, upturned nose with a flat bridge, and a small lower jaw. Some affected infants are born with an opening in the roof of the mouth (a cleft palate).

The skeletal features of Weissenbacher-Zweymüller syndrome tend to diminish during childhood. Most adults with this condition are not unusually short, but do still retain the other features of Weissenbacher-Zweymüller syndrome.

Read more about otospondylomegaepiphyseal dysplasia.

How common is Weissenbacher-Zweymüller syndrome?

Weissenbacher-Zweymüller syndrome is very rare; only a few families with the disorder have been reported worldwide.

What genes are related to Weissenbacher-Zweymüller syndrome?

Mutations in the COL11A2 gene cause Weissenbacher-Zweymüller syndrome. The COL11A2 gene is one of several genes that provide instructions for the production of type XI collagen. This type of collagen is important for the normal development of bones and other connective tissues that form the body’s supportive framework. At least one mutation in the COL11A2 gene is known to cause Weissenbacher-Zweymüller syndrome. This mutation disrupts the assembly of type XI collagen molecules, resulting in delayed bone development and the other features of this disorder.

Read more about the COL11A2 gene.

How do people inherit Weissenbacher-Zweymüller syndrome?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Most cases of this condition result from new (de novo) mutations in the gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family.