HEREDITY
MUTATIONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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destroys nerve cells in the brain.
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destroys nerve cells in the spinal cord.
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that causes red blood cells to become misshapen and break down.
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Detailed explanation-1: -The genetic change that causes Tay-Sachs disease results in a deficiency of the enzyme beta-hexosaminidase A. This enzyme is required to break down the fatty substance GM2 ganglioside. The buildup of fatty substances damages nerve cells in the brain and spinal cord.
Detailed explanation-2: -Tay-Sachs disease is part of a group of genetic disorders called the GM2 gangliosidoses. Affected children appear to develop without a problem until about 6 months of age and then begin to show neurological symptoms, including: Slowing of development. Progressive loss of mental ability.
Detailed explanation-3: -Infants with this condition develop an exaggerated startle reaction to loud noises. As the disease progresses, children with Tay-Sachs disease experience involuntary muscle twitches (myoclonic jerks), seizures, difficulty swallowing (dysphagia), vision and hearing loss, and intellectual disability.
Detailed explanation-4: -The disease is named after British ophthalmologist Waren Tay, who in 1881 first described a symptomatic red spot on the retina of the eye; and American neurologist Bernard Sachs, who described in 1887 the cellular changes and noted an increased rate of disease in Ashkenazi Jews.