What is Tay-Sachs disease?
Tay-Sachs disease is a rare neurological disorder. Individuals with this disorder cannot break down a normal substance in the body called GM2 ganglioside, a type of fatty material called a lipid. Because they can't break this substance down, it builds up in cells of the body, particularly nerve cells in the brain and spinal cord. When enough of this fatty material builds up, it destroys the cells and damages the surrounding tissue. The most common form of Tay-Sachs disease is the early infantile form. The first sign is often an exaggerated startle response, which means when an infant is startled the reaction is disproportionate to whatever startled him or her. Infants will eventually lose previously acquired skills like the ability to sit up or hold up their head. As they age, additional symptoms can develop including seizures, vision problems, hearing loss and intellectual disability. Eventually, children will become less aware of their surroundings and voluntary movements will decrease. Death usually occurs around four years of age. Tay-Sachs disease is caused because people have a change or alteration (mutation) in both their HEXA genes. This gene produces an enzyme that is needed to break down GM2 ganglioside. Tay Sachs is inherited in an autosomal recessive manner, which means that a child inherits one altered HEXA gene from each parent.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/tay-sachs-disease/overview/42417 • DATE UPDATED: 2016-09-23
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Tay-Sachs disease. Genetics Home Reference website. Accessed September 20, 2016. https://ghr.nlm.nih.gov/condition/tay-sachs-disease