Hexosaminidase Deficiency

M. C. Patterson

Research output: Chapter in Book/Report/Conference proceedingChapter


Hexosaminidas degrades GM2 to GM3 ganglioside. The enzyme exists in three isoforms, Hex A, Hex B, and Hex S. Mutations of the gene encoding the α subunit cause Hex A and S deficiency, whereas mutations of the β subunit cause combined Hex A and B deficiency. Tay-Sachs disease, the classic, rapidly progressive infantile form of GM2 gangliosidosis, results from Hex A deficiency; Sandhoff's disease, indistinguishable from Tay-Sachs except for variable organomegaly, results from Hex A and B deficiency. Activator protein deficiency can produce similar phenotypes; less marked deficiencies of Hex A can present as slowly progressive disorders in later life.

Original languageEnglish (US)
Title of host publicationEncyclopedia of the Neurological Sciences
PublisherElsevier Inc.
Number of pages2
ISBN (Electronic)9780123851574
ISBN (Print)9780123851581
StatePublished - Jan 1 2014



  • Activator protein
  • Ataxia
  • Cherry-red spot
  • Dystonia
  • Hexosaminidase
  • Optic atrophy
  • Sandhoff
  • Spinal muscular atrophy
  • Tay-Sachs
  • Vertical supranuclear gaze palsy

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Patterson, M. C. (2014). Hexosaminidase Deficiency. In Encyclopedia of the Neurological Sciences (pp. 564-565). Elsevier Inc.. https://doi.org/10.1016/B978-0-12-385157-4.00098-1