GM3 Gangliosidosis. GM3-UPD-N-acetylgalactosaminyltransferasa deficiency.
Incidence
The inheritance is probably X-linked. Only a few patients have been reported.
Clinical Characteristics
This is an exceptional condition characterized by poor physical development, abnormal facies, rapid neurological deterioration and early death. There seems to be a deficiency in lysosomal alpha-N-acetylgalactosaminidase. Pathologically they resemble neuroaxonal dystrophy. The clinical signs include poor physical and motor development, coarse facies, macroglossia, gingival hypertrophy, stubby hands and feet, large inguinal hernia, hepatosplenomegaly, and normal fundi. Death may occur in the first few months of life. Ganglioside GM3 is demonstrated in liver and brain and there is total absence of higher ganglioside homologs. The enzyme deficiency seems to be N-acetylgalactosaminyltransferase. There are no vacuolated lymphocytes. Marrow cells are normal. There is neither edema nor radiographic changes in bone. Major clinical characteristics are delayed growth, loose skin, coarse facies, depressed nasal bridge, macroglossia, gingival hypertrophy and micrognatia. There is delayed motor development and neonatal hypotonia. There is GM3-UPD-N-acetylgalactosaminyltransferasa deficiency.
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
EB-W, EB-F. Ganglioside GM3 is demonstrated in liver and brain and there is total absence of higher ganglioside homologs. The enzyme deficiency seems to be N-acetylgalactosaminyltransferase.