An autosomal recessive neurodegenerative disorder characterized by the onset in infancy of an exaggerated startle response, followed by paralysis, dementia, and blindness. It is caused by mutation in the alpha subunit of the HEXOSAMINIDASE A resulting in lipid-laden ganglion cells. It is also known as the B variant (with increased HEXOSAMINIDASE B but absence of hexosaminidase A) and is strongly associated with Ashkenazic Jewish ancestry.

An outdated term for Tay-Sachs disease.

Synonyms: HexA Deficiency, Deficiency Disease Hexosaminidase A, Gangliosidosis GM2 , Type 1, Sphingolipidosis, Tay-Sachs, Gangliosidosis G(M2), Type I, Gangliosidosis GM2, Type I, Deficiency, Hexosaminidase A, Amaurotic Familial Idiocy, G(M2) Gangliosidosis, Type I, Tay Sachs Disease, B Variant GM2-Gangliosidosis, B Variant GM2 Gangliosidosis, B Variant GM2-Gangliosidoses, GM2 Gangliosidosis, Type 1, Hexosaminidase alpha Subunit Deficiency (Variant B), Type I GM2-Gangliosidosis, GM2 Gangliosidosis, B Variant, Sphingolipidosis, Tay Sachs, Familial Amaurotic Idiocy, GM2-Gangliosidosis, Type I, Deficiency, Hexosaminidase alpha-Subunit (Variant B), GM2 Gangliosidosis, Type I, Hexosaminidase alpha-Subunit Deficiency (Variant B), Amaurotic Idiocy, Familial, Hexosaminidase A Deficiency, Gangliosidosis GM2, B Variant, Tay Sachs Disease, B Variant, GM2-Gangliosidosis, B Variant, Tay-Sachs Disease, Hexosaminidase A Deficiency Disease, Tay-Sachs Sphingolipidosis, Tay-Sachs Disease, B Variant