| Georgette Kollmorgens Web Page On Tay Sachs Disease Definition Causation Developments and Symptoms Who is a risk for the disease? ... References Definition Tay Sachs disease is an inherited autosomal recessive disorder (inherited in the same manner that hair and eye color are passed on to offspring) that result in a progressive destruction of the Central Nervous System, leading to death before the age of five. It is Lysosomal Storage Disorder or Mucopolysaccaridoses, which are progressive disorders involving multiple organs in which there is an excessive buildup of carbohydrates. Causation Tay Sachs is caused by an accumulation of GM gangliosides, due to a deficiency or lack of lysosomal Hexosaminidase A. Lysosoaml Hex A is an enzyme needed for neurological development to occur normally. In the absence of Hex-A, the lipid GM ganglioside builds up in cells, mostly the nerve cells of the brain. In time, this excessive accumulation causes the neurons of the Central Nervous System, and other Neurons throughout the body to swell and become distorted. As the disease progresses, the neurons are lost and the total number of neurons in the body increasingly diminishes. The Tay Sachs Chromosome mutation is located at 15q22-q25 on a gene map. It was found that there was a mRNA mutation that was a 4-nucleotide insertion in exon 11. Development and Symptoms: Who is at risk for the disease Tay Sachs Disease occurs when both parents are carries of the disorder. When both parents are carriers there is a 25% chance that their child will have the disease, any a 50% chance that the child will be a carrier. The disease occurs mainly in the Ashkenazi Jewish population of Eastern European origin. The reason why Tay Sachs is mainly found in Ashkenazi Jew is thought to be because of polygamy, small effected population size, and inbreeding. This would have produced a large amount of offspring that could have ultimately elevated the frequency of the TSD allele in the descendants of the populations. | |
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