Mucolipidosis I (Acid Neuraminidase Deficiency)

Abstract
• Isolated deficiency of the lysosomal hydrolase acid neuraminidase results in multisystem storage of sialic acid-rich oligosaccharides. Wide phenotypic diversity occurs within this biochemical defect. We studied three cases of an infantile form of mucolipidosis I in which the phenotype is dominated by severe Hurloid features. These patients excreted excessive amounts of sialic acid-rich oligosaccharides in their urine, and storage of similar compounds was shown in tissues and cultured fibroblasts. Cultured fibroblasts demonstrated an isolated deficiency of acid neuraminidase; β-galactosidase levels were normal. (Am J Dis Child1981;135:703-708)