Sialidosis (Neuraminidase-Mucolipidosis Type I ) is a lysosomal storage disease caused by insufficient neuraminidase enzyme. Patients are clinically categorized as Type I and Type II.

Depending on the type of the disease – Type I or Type II- those anomalies can be observed which are: hydrops foetalis( prenatal), coarse facial appearance, dizostozis multiplex, muscle atrophy and weakness, hearing loss, and progressive loss of vision.