Strisciuglio_1988_Hum.Genet_80_304

The biochemical defect underlying the late infantile form of galactosialidosis has been investigated in fibroblasts from two patients presenting with this phenotype. Immunoprecipitation experiments demonstrated that a reduced amount of 32-kd "protective" protein and a normal amount of its precursor are present in late infantile galactosialidosis fibroblasts, while neither of the two polypeptides are detectable in early infantile and juvenile/adult fibroblasts. Leupeptin treatment led to a slight increase in the amount of 54-kd and 32-kd polypeptides in both late-infantile galactosialidosis cell lines. Uptake studies in one of the two cell lines confirmed the hypothesis that a block in the maturation of the protective protein is responsible for the late infantile type of galactosialidosis. This mutation seems to be a distinct finding in all patients affected by this form of the disease.