Alpha-mannosidosis: analysis of urinary oligosaccharides with high performance liquid chromatography and diagnosis of a case with unusually mild presentation.

Mannose containing oligosaccharides (OS) excreted in the urine of patients with alpha-mannosidosis have been analyzed with high performance liquid chromatography (HPLC). The HPLC method provides a highly sensitive assay for detection of the urinary oligosaccharides and was employed for diagnosis of a fifteen-year-old female with an unusually mild presentation of the disease. Dysostosis multiplex and coarse facies were absent; mental impairment was particularly mild. The elution profile of the urinary OS from this patient and two, more severely affected, patients with mannosidosis were nearly identical, containing nine major OS fractions. The concentrations of the OS were eight fold lower in our patient but, when calculated relative to creatinine, the levels of the urinary OS of all patients were similar.