Definition
Tay-Sachs disease is an inherited metabolic disease caused by the harmful buildup of lipids (fatty materials such as oils and acids) in various cells and tissues in the body. Â It is part of a group of genetic disorders called the GM2Â gangliosidoses.
Tay-Sachs and its variant form are caused by a deficiency in the enzyme hexosaminidase A. Affected children appear to develop normally until about age 6 months and then begin to show symptoms, including:
- progressive loss of mental ability,
- dementia,
- blindness,
- increased startle reflex to noise,
- progressive loss of hearing leading to deafness,
- difficulty with swallowing,
- seizures that may begin in the child’s second year, and
- “cherry-red” spots in their eyes.
A much rarer form of the disorder, called late-onset Tay-Sachs disease, occurs in individuals in their twenties and early thirties and is characterized by an unsteady gait and progressive neurological deterioration.
The incidence of Tay-Sachs has been particularly high among people of Eastern European and Askhenazi Jewish descent., as well as in certain French Canadians and Louisiana Cajuns. Affected individuals and carriers of Tay-Sachs disease can be identified by a blood test that measures hexosaminidase A activity. Both parents must carry the mutated gene in order to have an affected child.
In these instances, there is a 25 percent chance with each pregnancy that the child will be affected with Tay-Sachs disease. Prenatal diagnosis is available if desired. Â A very severe form of Tay-Sachs disease is known as Sandhoff disease, which is not limited to any ethnic group.
Even with the best of care, children with Tay-Sachs disease usually die by age 4, from recurring infection.
Presently there is no specific treatment for Tay-Sachs disease. Anticonvulsant medicine may initially control seizures. Other supportive treatment includes proper nutrition and hydration and techniques to keep the airway open. Children may eventually need a feeding tube.
Source: https://www.ninds.nih.gov/