g(m2)-ganglioside and Cerebellar-Ataxia

The authors describe the clinical phenotypes of hexosaminidase deficiencies (GM2 gangliosidosis). The symptoms, differently combined, include cerebellar ataxia, motor neuron disease, dystonia, psychosis, neurovegetative troubles with different severity. Morphological changes are evident in rectal, muscle or nerve biopsies. Minor clinical changes are described in carriers from a family. A chronic GM2 gangliosidosis has to be suspected in any atypical case with the above-mentioned symptoms with autosomal-recessive inheritance.

Topics: Adolescent; Adult; beta-N-Acetylhexosaminidases; Biopsy; Cerebellar Ataxia; Child; Diagnosis, Differential; Dystonia; Electrodiagnosis; G(M2) Ganglioside; Gangliosidoses; Genes, Recessive; Genetic Carrier Screening; Humans; Motor Neuron Disease; Neurocognitive Disorders; Pedigree; Phenotype; Radiography; Sandhoff Disease; Tay-Sachs Disease

An Ashkenazi Jewish brother and sister developed progressive ataxia and proximal neurogenic muscle weakness, associated with supranuclear ophthalmoplegia, in the fourth decade of life. Hexosaminidase A activity, assayed using both synthetic and natural substrates, was severely reduced in the patients' plasma, leukocytes, and skin fibroblasts. Enzyme activity in their parents was in a similar range to that seen in heterozygotes for Tay-Sachs disease. The increasing evidence for marked clinical and molecular heterogeneity in the GM2 gangliosidoses warrants their consideration in the diagnosis of multisystem degenerative neurological disorders, even if onset of symptoms is in adult life.

Topics: Age Factors; beta-N-Acetylhexosaminidases; Cerebellar Ataxia; Female; G(M2) Ganglioside; Hexosaminidase A; Humans; Male; Middle Aged; Muscular Diseases; Ophthalmoplegia; Radiography; Syndrome