Selenophosphate synthetase 1 (SEPHS1) plays an essential role in the metabolism of selenium and has ATPase activity that synthesizes selenophosphate from ATP and selenide. Researchers have hypothesized the potential involvement of SEPHS1 in genetic disorders. They presented a series of case reports involving 9 individuals with heterozygous missense variants in the SEPHS1 gene; all these variants resided in the C-terminal domain or near the AIR synthase-related domain of the gene.