What body system does Tay-Sachs affect?

What body system does Tay-Sachs affect?

Tay-Sachs disease affects the nerve cells in the brain and spinal cord.

What gene is affected by the mutation Tay-Sachs disease?

Tay-Sachs disease is caused by a change (mutation) in the hexosaminidase subunit alpha (HEXA) gene.

Why is Tay-Sachs caused by a recessive allele?

Tay-Sachs disease is inherited in an autosomal recessive manner. This means that to have the disease, a person must have a mutation in both copies of the responsible gene in each cell. There is nothing either parent can do, before or during a pregnancy, to cause a child to have Tay-Sachs disease.

What are the genes that cause Tay Sachs disease?

Tay-Sachs disease. Tay-Sachs is an autosomal recessive disease caused by mutations in both alleles of a gene ( HEXA) on chromosome 15. HEXA codes for the alpha subunit of the enzyme β-hexosaminidase A. This enzyme is found in lysosomes, organelles that break down large molecules for recycling by the cell.

Can a person with Tay Sachs disease be healthy?

If either or both Hex-A genes are active, the body produces enough of the enzyme to prevent the abnormal build-up of the GM2 ganglioside lipid. Carriers of Tay-Sachs – people who have one copy of the inactive gene along with one copy of the active gene – are healthy.

What causes the lack of hexosaminidase in Tay Sachs?

Tay-Sachs is caused by the absence of a vital enzyme called hexosaminidase-A (Hex-A). Without Hex-A, a fatty substance, or lipid, called GM2 ganglioside accumulates abnormally in cells, especially in the nerve cells of the brain.

How does GM2 ganglioside cause Tay Sachs disease?

As a result, this substance accumulates to toxic levels, particularly in neurons in the brain and spinal cord. Progressive damage caused by the buildup of GM2 ganglioside leads to the destruction of these neurons, which causes the signs and symptoms of Tay-Sachs disease.

What is the cause of Tay Sachs disease?

Tay-Sachs disease (TSD) is a fatal genetic disorder, most commonly occurring in children, that results in progressive destruction of the nervous system. Tay-Sachs is caused by the absence of a vital enzyme called hexosaminidase-A (Hex-A). Without Hex-A, a fatty substance, or lipid,…

What happens to the HEXA gene in Tay Sachs?

The HEXA gene provides instructions for making a type of enzyme known as hexosaminidase A. This enzyme is responsible for breaking down a fatty substance known as GM2 ganglioside. In persons with Tay-Sachs disease, hexosaminidase A no longer functions as it should.

How old do you have to be to die from Tay Sachs?

By the time a child with Tay-Sachs is three or four years old, the nervous system is so badly affected that death usually results by age five. A much rarer form of Tay-Sachs, Late-Onset Tay-Sachs disease, affects adults and causes neurological and intellectual impairment. Only recently identified, the disease has not been extensively described.

When do you test for Tay Sachs disease?

Today most cases of Tay-Sachs disease occur in populations thought not to be at high risk. Prenatal testing for Tay-Sachs can be performed around the 11th week of pregnancy using chorionic villi sampling (CVS). This involves removing a tiny piece of the placenta.