What deficiency results in sialidosis?

• A. Alpha-iduronidase
• B. Beta-galactosidase
• C. Neuraminidase
• D. Glucose-6-phosphatase

Answer: (C)

Sialidosis is a lysosomal storage disorder caused by a deficiency in neuraminidase, which is responsible for the hydrolysis of sialic acid residues from glycoproteins and glycolipids. This enzymatic deficiency leads to the accumulation of sialylated oligosaccharides in various tissues, particularly affecting the central nervous system, and results in neurological deficits along with other clinical manifestations.

The condition is characterized by symptoms such as developmental delays, ataxia, and ocular symptoms, including cherry-red spots on the macula. The accumulation of sialylated compounds is significant in developing the clinical features associated with sialidosis.

In this scenario, focusing on the role of neuraminidase highlights the biochemical pathways disrupted by its deficiency, specifically the metabolism of sialic acid, contributing to the clinical picture of the disorder. This understanding is crucial for recognizing the specific enzymatic deficiencies and their corresponding disorders within the lysosomal storage diseases.