Combined sialidase (neuraminidase) and β‐galactosidase deficiency. Clinical, morphological and enzymological observations in a patient

Publisher Website
Google Scholar
Abstract
A patient with combined deficiency of sialidase and .beta.-galactosidase is described. This now 39-yr-old man, who is of Japanese origin, showed gradually progressive clinical features from the age of 6 yr. Many of these features are commonly found in sialidosis type 2 or in GM1-gangliosidosis. Both sialidase and .beta.-galactosidase activities were deficient in leukocytes and cultured fibroblasts. Leukocytes of his mother showed activities of both enzymes in the lower limit of the control range. Morphologically, the pattern of storage products in a skin biopsy resembled in many respects that seen in GM1-gangliosidosis. Storage products which could be typical of sialidosis were also observed. Since the patient showed angiokeratomata, the morphological findings were compared with those specific to Fabry''s disease, but no similarities were found. An enzymological diagnosis of the disease is most reliable on cultured fibroblasts, discriminating it from sialidosis type 2 and GM1-gangliosidosis. In view of recent findings, leukocytes seem to be less suitable for the establishment of the diagnosis galactosialidosis.