The ARSL 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 molecules that contain chemical groups known as sulfates. 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.
Genetic changes involving the ARSL 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 ARSL 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 ARSL 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.
- arylsulfatase E (chondrodysplasia punctata 1)