Tay-Sachs Disease

Tay-Sachs disease isa rare inherited disorder that results in slow destruction of tbe central nervous system (brain and spinal cord).

What Is Tay-Sachs Disease?

Tay-Sachs disease is a rare metabolic disorder with severe neurologic (nervous system) symptoms. The term "metabolic" refers to the body's chemical processes that produce protein and other substances and break down nutrients to release energy. Tay-Sachs disease is a metabolic disorder because it is caused by the absence of the enzyme (a type of protein) hexosaminidase A (Hex-A). Hex-A is necessary for breaking down fatty substances called lipids. Without Hex-A, these lipids build up in, and eventually destroy, the nerve cells in the brain. Ultimately, the nervous system stops functioning properly.

How Does Tay-Sachs Disease Affect the Body?

Classical Tay-Sachs:

The most common form of Tay-Sachs disease (classical Tay-Sachs) affects children and usually is fatal. It is caused by a complete lack of Hex-A. Destruction of nerve cells begins before birth, but affected babies do not begin to lose nerve function until they are about six months old. By age two, the child may have seizures and begins to lose skills such as crawling, sitting, turning over, and reaching for objects. Eventually, the child will be blind, paralyzed, and mentally retarded. Children with this form of Tay-Sachs disease do not live past five years of age.

A variation of this scenario occurs when children develop symptoms between the ages of two and five years of age rather than as an infant. The same symptoms emerge, but the disease progresses more slowly. Children with this form usually die by age 15.

Late onset Tay-Sachs (LOTS): 

Late onset Tay-Sachs disease (LOTS) is less common than the infantile form. It affects teenagers and adults in their twenties and thirties by causing a gradual loss of nerve function. People with LOTS have low levels of Hex-A rather than a complete lack of it. As LOTS develops, people affected by it may grow clumsy, uncoordinated, and moody. They may experience muscle weakness, twitching, slurred speech, and intellectual impairment. The symptoms vary in type and severity from person to person. Because this form develops so gradually, life expectancy of affected people seems to be similar to that of unaffected people.