SNP Shot: Genomic Insights

Weissenbacher-Zweymüller syndrome is a disorder impacting bone development, marked by skeletal irregularities, hearing impairment, and characteristic facial traits. Its symptoms closely resemble those of otospondylomegaepiphyseal dysplasia (OSMED) and Stickler syndrome type III. Because all three conditions stem from mutations in the same gene, distinguishing between them can be challenging. Some experts suggest they may represent varying expressions of the same underlying disorder.

Newborns with Weissenbacher-Zweymüller syndrome often exhibit reduced birth size due to shortened arm and leg bones. These bones, particularly in the thigh and upper arm, have broadened ends, giving them a dumbbell-like appearance. The spinal bones (vertebrae) can also display abnormal shapes. Some individuals also experience high-frequency hearing loss. Characteristic facial features include widely spaced, prominent eyes, a small, upturned nose with a flattened nasal bridge, and a receding lower jaw. Cleft palate may also be present at birth in some cases.

A significant increase in bone growth ("catch-up growth") in the limbs typically occurs during childhood for individuals with Weissenbacher-Zweymüller syndrome. Consequently, adults with this condition typically reach a normal height. However, they retain other hallmarks of the syndrome, such as distinctive facial features and hearing loss.

Inheritance:

Weissenbacher-Zweymüller syndrome follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene in each cell is enough to cause the condition. In most instances, the syndrome arises from a new (de novo) gene mutation during the development of eggs or sperm or in the early stages of embryonic development. These cases occur in individuals with no family history of the disorder.