Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.

Diseases

Genetic and Rare Diseases Information Center (GARD)

Print friendly version

Tay Sachs disease


Other Names for this Disease

  • B variant GM2 gangliosidosis
  • Gangliosidosis GM2 , type 1
  • GM2 gangliosidosis, type 1
  • HexA deficiency
  • Hexosaminidase A deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have a friend whose 8 month-old baby was recently diagnosed with Tay-Sach disease. Very few other children in the my country have been diagnosed with this disease and I’m desperate to learn more about it such its treatment and the availability of clinical trials.


Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is Tay-Sachs disease?

Gangliosidosis (GM2) type 1, also known as Tay-Sachs disease, is a rare inherited disorder that causes progressive destruction of nerve cells in the brain and spinal cord. 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. This ongoing accumulation causes progressive damage to the cells.[1]
Last updated: 8/14/2012

How is Tay-Sachs disease inherited?

This condition is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder. [2]
Last updated: 3/3/2010

What are the symptoms of Tay-Sachs disease?

The most common form of Tay-Sachs disease begins in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. As the disease progresses, infants develop seizures, vision and hearing loss, mental retardation, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Children with this severe form of Tay-Sachs disease usually live only into early childhood.[2]

Other forms of Tay-Sachs disease are much rarer. Signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form of Tay-Sachs disease. As in the infantile form, mental abilities and coordination are affected. Characteristic features include muscle weakness, loss of muscle coordination (ataxia) and other problems with movement, speech problems, and mental illness. These signs and symptoms vary widely among people with late-onset forms of Tay-Sachs disease.[2]
Last updated: 8/14/2012

How common is Tay-Sachs disease?

Tay-Sachs disease is very rare in the general population. The genetic mutations that cause this disease are more common in people of Ashkenazi (eastern and central European) Jewish heritage than in those with other backgrounds. The genetic mutations that cause Tay-Sachs disease are also more common in certain French-Canadian communities of Quebec, some Amish groups, and the Cajun community of Louisiana.[2]
Last updated: 8/14/2012

How might children with Tay-Sachs disease be treated?

Although several attempts have been made at purified enzyme replacement therapy for children with Tay-Sachs disease, none has been successful. Cellular infusions and even bone marrow transplantation have been attempted with no evidence of benefit. Because no specific treatment is available for Tay-Sachs disease, treatment is directed at the symptoms and major associated conditions.[3]

Treatment is supportive and aimed at providing adequate nutrition and hydration. The airway must be protected. Seizures can be controlled initially with conventional anticonvulsant medications such as benzodiazepines, phenytoins, and/or barbiturates, but the progressive nature of the disease may require alteration of dosage or medication. Infectious diseases should be managed. In advanced disease, good bowel movement should be maintained and severe constipation should be avoided. Good hydration, food additives, stool softeners, laxatives, and other measures should be employed to avoid severe constipation.[3]
Last updated: 8/14/2012

Are there other therapies under investigation for treatment of Tay-Sachs disease?

Central nervous system enzyme replacement or neuronal-corrective gene therapy are experimental considerations for treatment of Tay -Sachs disease at present, but are only at the theoretical stage clinically. A genetically engineered mouse model of infantile Tay -Sachs disease has been constructed and is now being used to evaluate innovative treatment modalities. Most recently, clinical trials have been initiated, utilizing enzymatic inhibitors which block (reduce) the biosynthesis of glycoshingolipids such as GM2 ganglioside . One such agent, N- deoxynigiromycin , has shown some efficacy with the non-CNS neuronal storage disorder, type I Gaucher disease.[3][4]
Last updated: 8/14/2012

References
Other Names for this Disease
  • B variant GM2 gangliosidosis
  • Gangliosidosis GM2 , type 1
  • GM2 gangliosidosis, type 1
  • HexA deficiency
  • Hexosaminidase A deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.