| Subject | Contents |
| Definition | A familial disorder found predominantly in Ashkenazi Jewish families, which results in early death. |
| Alternative Names | |
| Causes, incidence, and risk factors | Tay-Sachs disease is caused by a deficiency of hexosaminidase, an enzyme that is important in the metabolism of gangliosides (a type of chemical substance found in nerve tissue). These gangliosides, particularly ganglioside GM2, then accumulate in the brain, causing neurological deterioration. Tay-Sachs disease is inherited as a recessive gene, and 1 out of every 25 members of the Ashkenazi Jewish population carries the gene. The incidence is 1 out of 2,500 people in this population.
Depending on the age of onset and clinical features, Tay-Sachs has been classified into infantile-, juvenile-, and adult-onset forms. The majority of people with Tay-Sachs, however, have infantile forms. Symptoms begin to appear at 3 to 6 months old. The disease unfortunately tends to progress rapidly, and the child usually dies by the age of 4 or 5 years. |
| Symptoms | Loss of motor skills Increased startle reaction Decreased eye contact ( blindness ) DeafnessDementia Listlessness Irritability SeizuresParalysisDecreased muscle tone (loss of muscle strength) Muscle function loss Delayed mental and social skills Slow growth |
| Signs and tests | Family history Physical examinationEnzyme analysis of blood/body tissue for hexosaminidase levels Eye exam reveals a cherry-red spot in the macula |
| Treatment | Only supportive treatment is available. |
| Support Groups | The stress of illness can often be helped by joining support groups where members share common experiences and problems. See Tay-Sachs - support group . |
| Expectations (prognosis) | Children affected with this disease have progressive symptoms and usually die by 4 to 5 years old. |
| Complications | Note: Symptoms appear during the first 3 to 10 months of life and progress to loss of all voluntary movements, spasticity and seizures , and eventually death by 4 to 5 years old. |
| Calling your health care provider | Go to the emergency room or call the local emergency number (such as 911) if this is the child's first seizure , if the seizure is different than other previous seizures , if the child has difficulty breathing , or if the seizure lasts longer than 2-3 minutes. Call for an appointment with your health care provider if your child experiences a seizure lasting less than 2-3 minutes or has other noticeable behavioral changes. |
| Prevention | There is no known way to prevent this disorder. However, genetic testing can detect carriers of the gene for this disorder and is recommended prior to conception for couples from at risk populations. Prenatal diagnosis is possible from amniotic fluid studies. |
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