Co-therapy with S-adenosylmethionine and nicotinamide riboside improves t-cell survival and function in Arts Syndrome (PRPS1 deficiency).

Arts syndrome or phosphoribosyl-pyrophosphate-synthetase-1 (PRPS1) deficiency is caused by loss-of-function mutations in the PRPS1 gene (Xq22.3). PRPS1 is an initial and essential step for the synthesis of the nucleotides of purines, pyrimidines, and nicotinamide. Classically, affected males present with sensorineural hearing loss, optic atrophy, muscular hypotonia, developmental impairment, and recurrent severe respiratory infections early in life. Treatment of a 3-year old boy with S-adenosylmethionine (SAM) replenished erythrocyte purine nucleotides of adenosine and guanosine, while SAM and nicotinamide riboside co-therapy further improved his clinical phenotype as well as T-cell survival and function.