Tay-sachs Disease Yi Cheng Lisa Nguyen

Symptoms of Tay-Sachs Disease Infantile Tay-Sachs Disease: Infants with Tay-Sachs disease appear to develop normally for the first few months of life. As nerve cells become filled with fatty material, deterioration of mental and physical abilities occurs. The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. Other neurological symptoms include dementia, seizures, and an increased startle reflex to noise. Juvenile Tay-Sachs Disease: Extremely rare, Juvenile Tay-Sachs disease usually presents itself in children between 2 and 10 years of age. They develop cognitive, motor, speech difficulties (dysarthria), swallowing difficulties (dysphagia), unsteadiness of gait (ataxia), and spasticity. Patients with Juvenile TSD usually die between 5–15 years.

Adult/Late Onset Tay-Sachs Disease: A rare form of the disorder, known as Adult Onset Tay-Sachs disease or Late Onset Tay-Sachs disease (LOTS), occurs in patients in their 20s and early 30s. It is characterized by unsteadiness of gait and progressive neurological deterioration. Symptoms of LOTS, which present in adolescence or early adulthood, include speech and swallowing difficulties, unsteadiness of gait, spasticity, cognitive decline, and psychiatric illness, particularly schizophrenic-like psychosis.

The Genetics Tay-Sachs is an autosomal recessive disease caused by mutations in both alleles of a gene (HEXA) on chromosome 15. The HEXA gene provides instructions for making part of an enzyme called beta-hexosaminidase A, found in lysosomes, which catalyzes the break down of acidic fatty materials called GM2 gangliosides.

In Tay-Sachs individuals, the enzyme is absent or present only in very reduced amounts, which allows excessive accumulation of the GM2 ganglioside in neurons found in the brain and spinal cord. The buildup of GM2 leads to the destruction of the neuron, which causes the signs and symptoms of Tay-Sachs disease.

The disease For people with the disease, symptoms don’t start until the child is several months old. By 3 or 4 years old, the nervous system is in bad shape, and the child almost certainly dies. Some children live a little longer than 5 years old, but the majority die under 5 years old. People with the disease have difficulty living their everyday lives like others. Not only is moving around hard, but also just swallowing and speaking. Their families have to continually bring them to the hospital for checkups, and many kids even just stay in the hospital.

Treatment and Prevention There is no current cure for Tay-Sachs. Treatment is focused on controlling the symptoms-feeding those diagnosed with Tay-Sachs, controlling seizures, etc. Doctors have been trying to cure the late on-set form of Tay-Sachs by a pharmacological chaperone (PYR). There is also stem cell research being carried on, but as of yet, there is not enough information for specific results about reversing or slowing damage to the central nervous system for people with Tay- Sachs. The only way to prevent Tay-Sachs from being inherited is by testing for Tay-Sachs and avoid marrying a spouse who is a carrier for this disease.

History Tay-Sachs is named after two physicians Warren Tay (British) first described the red spot on the retina that is indicative of the disease in 1881. Bernard Sachs (American) described the changes that occur within cells. He noticed the prevalence of Tay-Sachs in the Ashkenazi Jewish population. Up until recently, Tay-Sachs was thought to be just for infants. In the 1970s and the 1980s, adult forms of the disease was uncovered due to new information about the molecular biology of the disease. Other cultures have been found to have a higher incidence of HEXA gene mutations (Cajuns). There are no famous people who have Tay-Sachs disease, due to the fatality of the disease.

Works Cited http://www.fairfaxcryobank.com/geneticdiseasedetails.shtml http://ghr.nlm.nih.gov/condition/tay-sachs-disease http://www.ncbi.nlm.nih.gov/books/NBK22250/ http://www.biotechpark.org.in/misf/HTML/Tay-Sachs_Disease.html http://www.ninds.nih.gov/disorders/taysachs/taysachs.htm http://nervous-system.emedtv.com/tay-sachs-disease/history-of-tay-sachs-disease.html http://www.curetay-sachs.org/about.shtml