ARSE

The ARSE gene provides instructions for making an enzyme called arylsulfatase E. This enzyme is part of a group known as sulfatases, which are enzymes that help process sulfate-containing molecules. Sulfatases play important roles in cartilage and bone development.

Within cells, arylsulfatase E is located in the Golgi apparatus, a structure that modifies newly produced enzymes and other proteins. The function of this enzyme is unknown, although researchers believe it participates in a chemical pathway involving vitamin K. Evidence suggests that vitamin K normally plays a role in bone growth and maintenance of bone density.

X-linked chondrodysplasia punctata 1 - caused by mutations in the ARSE gene

Genetic changes involving the ARSE gene are responsible for X-linked chondrodysplasia punctata 1, a disorder of bone and cartilage development that occurs almost exclusively in males. Between 60 and 75 percent of males with the characteristic features of this condition have a mutation within the ARSE gene. At least 18 mutations have been found in affected individuals; these genetic changes reduce or eliminate the function of arylsulfatase E. Another 25 percent of affected males have a small deletion of genetic material from the region of the X chromosome that contains the ARSE gene. These individuals are missing the entire gene, so their cells produce no functional arylsulfatase E.

It is unclear how a shortage of arylsulfatase E disrupts the development of bones and cartilage and leads to the characteristic features of X-linked chondrodysplasia punctata 1.