Arts syndrome

Arts syndrome is caused by mutations in the PRPS1 gene. This gene provides instructions for making an enzyme called phosphoribosyl pyrophosphate synthetase 1, or PRPP synthetase 1. This enzyme is involved in producing purines and pyrimidines, the building blocks of DNA, RNA, and molecules such as ATP and GTP that serve as energy sources in the cell.

The PRPS1 mutations that cause Arts syndrome replace one protein building block (amino acid) with another amino acid in the PRPP synthetase 1 enzyme. The resulting enzyme is likely unstable, compromising its ability to perform its normal function. The disruption of purine and pyrimidine production may impair energy storage and transport in cells. Impairment of these processes may have a particularly severe effect on tissues that require a large amount of energy, such as the nervous system and the immune system, resulting in the neurological problems and immune dysfunction characteristic of Arts syndrome.

Arts syndrome is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only 1 X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell sometimes causes the disorder. Females with one copy of the mutated gene are typically much less severely affected.by Arts syndrome than males. In many cases, they do not experience any symptoms.

In the small number of Arts syndrome cases that have been identified, affected individuals have inherited the mutation from a mother who carries an altered copy of the PRPS1 gene.