Disease Information for Tay-Sachs disease: Definition

An autosomal recessive inherited gangliosidosis characterized by the onset in the first 6 months of life of an exaggerated startle response, delay in psychomotor development, hypotonia (followed by spasticity), visual loss, and a macular cherry red spot; Hexosaminidase A (see BETA-N-ACETYLHEXOSAMINIDASE) is deficient, leading to the accumulation of GM2 ganglioside in neurons of the central nervous system and retina; This condition is strongly associated with Askenazic Jewish ancestory;----------- (Menkes, Textbook of Pediatric Neurology, 5th ed)---Tay Sachs Disease; amaurotic Familial Idiocy ; Amaurotic Familial Infantile Idiocy; Cerebromacular Degeneration; GM2 Gangliosidosis, Type 1; Hexoaminidase Alpha-Subunit Deficiency (Variant B); Infantile Cerebral Ganglioside; Infantile Sipoidosis GM-2 Gangliosideosis (Type S); Lipidosis, ganglioside, infantile; Sphingolipidosis, Tay-Sachs; Tay-Sachs disease is a rare, neurodegenerative disorder in which deficiency of an enzyme (hexosaminidase A) results in excessive accumulation of certain fats (lipids) known as gangliosides in the brain and nerve cells; This abnormal accumulation of gangliosides leads to progressive dysfunction of the central nervous system; This disorder is categorized as a lysosomal storage disease; Lysosomes are the major digestive units in cells; Enzymes within lysosomes break down or "digest" nutrients, including certain complex carbohydrates and fats;

Symptoms associated with Tay-Sachs disease may include an exaggerated startle response to sudden noises, listlessness, loss of previously acquired skills (ie, psychomotor regression), and severely diminished muscle tone (hypotonia); With disease progression, affected infants and children may develop cherry-red spots within the middle layer of the eyes, gradual loss of vision, and deafness, increasing muscle stiffness and restricted movements (spasticity), eventual paralysis, uncontrolled electrical disturbances in the brain (seizures), and deterioration of cognitive processes (dementia); The classical form of Tay-Sachs disease occurs during infancy; an adult form (late-onset Tay-Sachs disease) may occur anytime from adolescence to the mid 30s; Tay-Sachs disease is inherited as an autosomal recessive trait; The disorder results from changes (mutations) of a gene known as the HEXA gene, which regulates production of the hexosaminidase A enzyme; The HEXA gene has been mapped to the long arm (q) of chromosome 15 (15q23-q24)

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