Galactosialidosis (GSL) is a lysosomal storage disease associated with a combined deficiency of beta-galactosidase (611458) and neuraminidase (608272), secondary to a defect in protective protein/cathepsin A (PPCA). All patients have clinical manifestations typical of a lysosomal disorder, such as coarse facies, cherry red spots, vertebral changes, foam cells in the bone marrow, and vacuolated lymphocytes. Three phenotypic subtypes are recognized. The early infantile form is associated with fetal hydrops, edema, ascites, visceromegaly, skeletal dysplasia, and early death. The late infantile type is characterized by hepatosplenomegaly, growth retardation, cardiac involvement, and rare occurrence of neurologic signs. The juvenile/adult form is characterized by myoclonus, ataxia, angiokeratoma, mental retardation, neurologic deterioration, absence of visceromegaly, and long survival. The majority of reported patients belong to the juvenile/adult group and are mainly of Japanese origin (summary by d'Azzo et al., 2001). (OMIM)

An autosomal recessive lysosomal storage disease caused by mutation(s) in the CTSA gene, encoding lysosomal protective protein. It is characterized by a combined deficiency of neuraminidase and beta-galactosidase.