Mass spectrometric quantification of plasma glycosphingolipids in human GM3 ganglioside deficiency

Among Amish communities of North America, biallelic mutations of ST3GAL5 (c.694C > T) eliminate synthesis of GM3 and its derivative downstream a- and b-series gangliosides. Systemic ganglioside deficiency is associated with infantile onset psychomotor retardation, slow brain growth, intractable epilepsy, deafness, and cortical visual impairment. We developed a robust quantitative assay to simultaneously characterize glycan and ceramide moieties of plasma glycosphingolipids (GSLs) among ST3GAL5 c.694C > T homozygotes (n = 8), their heterozygous siblings (n = 24), and wild type control (n = 19) individuals.