Background: In NANS deficiency, biallelic mutations in the -acetylneuraminic acid synthase () gene impair the endogenous synthesis of sialic acid (-acetylneuraminic acid) leading to accumulation of the precursor, -acetyl mannosamine (ManNAc), and to a multisystemic disorder with intellectual disability. The aim of this study was to determine whether sialic acid supplementation might be a therapeutic avenue for NANS-deficient patients.
Methods: Four adults and two children with NANS deficiency and four adult controls received oral NeuNAc acid (150 mg/kg/d) over three days.