Tay-Sachs+Disease

= Tay-Sachs Disease =

Genetic Mutationtoc
Tay-Sachs Disease, also known as TSD, is caused by a genetic mutation in the //HEXA// gene on chromosome 15. TSD is an autosomal recessive disorder. Any number of types of mutations is possible and range from insertions, deletions, and other point mutations. Regardless of the type of mutation, almost all changes in the gene sequence result in the production of a faulty amino acid sequence. This causes an incorrect structure and reduced function in the gene product. = =

Phenotypic Expression
A mutation in the HEXA gene results in the production of faulty beta-N-acetylhexosaminidase, a lysosomal enzyme. HEXA gene plays a role in the production of a lysosomal enzyme, beta-N-acetylhexosaminidase. The lysosome is the organelle responsible for the breakdown and recycling of materials in the cell. The lysosome is a like a large vesicle filled with hydrolytic enzymes that break down the various substance in the cell. Each enzyme is responsible for the breakdown of a specific type of molecule and beta-N-acetylhexosaminidase is one of these enzymes. As a result of the mutation in the beta-N-acetylhexosaminidase structure, the body is unable to breakdown a class of lipids known as gangliosides. This results in a build up of these lipids in the brain and impairs functioning of the brain. The picture below shows a build up of ganglioside in a neuron affected by Tay-Sachs. Due to the reduced brain function, TSD is classified as a neurological disease. ==

Symptoms of the Disease
TSD is an autosomal recessive disorder which means that both parents of any child born with the disease had to be carriers. The disease is most prevalent in people of eastern Europe or Ashkenazi Jewish decent. The disease is especially cruel in that a child with the disease is born and appears normal for the first 4-6 months of life. Neurological symptoms soon arise and become apparent. These symptoms include: Death always follows these symptoms and there is no known cure.
 * blind, deaf, and unable to swallow
 * atrophy and paralysis

For more information about the effort to find a cure go to http://www.curetay-sachs.org/

Tay-Sachs Disease. Accessed at http://en.wikipedia.org/wiki/Tay-Sachs_disease on February 7, 2011.
 * References**