Tay-Sachs disease

Also known as hexosaminidase A deficiency, Tay-Sachs disease (disorder), disease, Tay-Sachs, GM2 gangliosidosis, type 1, Hexosaminidase a Deficiency, Adult Type, Hexosaminidase alpha-subunit deficiency (variant B), Gm2-Gangliosidosis, Variant B1, Gm2-Gangliosidosis, Adult Chronic Type

Human medical condition

Key facts

Other names: GM2 gangliosidosis, hexosaminidase A deficiency
Specialty: Medical genetics
Symptoms: Initially : Decreased ability to turn over, sit, or crawl , Later : Seizures , hearing loss , inability to move
Usual onset: Three-to-six months of age
Duration: Long term
Types: Infantile, juvenile, late-onset
Causes: Genetic ( autosomal recessive )
Diagnostic method: Testing blood hexosaminidase A levels, genetic testing
Differential diagnosis: Sandhoff disease , Leigh syndrome , neuronal ceroid lipofuscinoses
Treatment: Supportive care , psychosocial support
Prognosis: Death often occurs in early childhood (3 months to 6 months)

Article

Tay–Sachs disease is an inherited fatal lysosomal storage disease that results in the destruction of nerve cells in the brain and spinal cord. The most common form is infantile Tay–Sachs disease, which becomes apparent around the age of three to six months, with the infant losing the ability to turn over, sit, or crawl. This is then followed by seizures, hearing loss, and inability to move, with death usually occurring by the age of three to five. Less commonly, the disease may occur later in childhood, adolescence, or adulthood (juvenile or late-onset). These forms tend to be less severe, but the juvenile form typically results in death by the age of 15.

Tay–Sachs disease is caused by a genetic mutation in the HEXA gene on chromosome 15, which codes a subunit of the hexosaminidase enzyme known as hexosaminidase A. It is inherited in an autosomal recessive manner. The mutation disrupts the activity of the enzyme, which results in the build-up of the molecule GM2 ganglioside within cells, leading to toxicity. Diagnosis may be supported by measuring the blood hexosaminidase A level or genetic testing. Tay–Sachs disease is a type of GM2 gangliosidosis and sphingolipidosis.