Neuraminidase deficiency in the cherry red spot-myoclonus syndrome

Two patients with the cherry red spot-myoclonus syndrome excreted excessive quantities of sialylated oligosaccharides in urine. Skin fibroblasts from both patients had a severe deficiency of neuraminidase activity using α-L-N-acetylneuraminosyl-(2→6′) lactose and a sialylhexasaccharide from their urine as substrates. A less severe deficiency was found using 2-(3′ methoxyphenyl)-N-acetylneuraminic acid, fetuin, and α-L-N-acetylneuraminosyl-(2→3′) lactose as substrates. I propose that the primary enzyme defect in this autosomal recessive disorder is a deficiency of lysosomal neuraminidase.