Mucolipidosis I - A sialidosis

Mucolipidosis I is characterized by Hurler‐like features and skeletal dysplasia with a cherry‐red macular spot and signs of neurodegeneration involving neuronal cells and myelin. Excessive amounts of sialic acid‐containing compounds were found in cultured fibroblasts, leukocytes, and urine of a patient with a clinical phenotype of mucolipidosis I. In cultured fibroblasts, profoundly diminished activity of an α‐N‐acetylneuraminidase (sialidase) was found. Mucolipidosis I thus appears to be a distinct disorder of complex carbohydrate catabolism caused by the genetic deficiency of a neuraminidase.