Arts syndrome

Arts syndrome is a rare inherited disorder that mainly harms the nervous system of boys. It is caused by mutations in the PRPS1 gene, which sits on the X chromosome, so the condition follows an X-linked pattern: males with one altered copy are severely affected, while females who carry a copy are often mildly affected or have no symptoms at all. The gene makes an enzyme, PRPP synthetase 1, that helps the cell produce purines and pyrimidines, the building blocks of DNA and RNA and of energy carriers such as ATP and GTP. Affected boys have profound sensorineural hearing loss, weak muscle tone, poor coordination, developmental delay and intellectual disability. In early childhood they lose vision because the optic nerve degenerates, and they develop weakness and loss of sensation in the limbs. Recurrent respiratory infections are common, and many affected boys do not survive past early childhood. In carrier females, hearing loss that starts in adulthood may be the only sign. Only a few families have been described in the medical literature.