Reviewed September 2008
What is Sandhoff disease?
Sandhoff disease is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord.
The most common and severe form of Sandhoff disease becomes apparent in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when their development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also develop an exaggerated startle reaction to loud noises. As the disease progresses, children with Sandhoff disease experience seizures, vision and hearing loss, intellectual disability, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Some affected children also have enlarged organs (organomegaly) or bone abnormalities. Children with the severe infantile form of Sandhoff disease usually live only into early childhood.
Other forms of Sandhoff disease are very rare. Signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form. 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 Sandhoff disease.
How common is Sandhoff disease?
Sandhoff disease is a rare disorder; its frequency varies among populations. This condition appears to be more common in the Creole population of northern Argentina; the Metis Indians in Saskatchewan, Canada; and people from Lebanon.
What genes are related to Sandhoff disease?
Mutations in the HEXB gene cause Sandhoff disease. The HEXB gene provides instructions for making a protein that is part of two critical enzymes in the nervous system, beta-hexosaminidase A and beta-hexosaminidase B. These enzymes are located in lysosomes, which are structures in cells that break down toxic substances and act as recycling centers. Within lysosomes, these enzymes break down fatty substances, complex sugars, and molecules that are linked to sugars. In particular, beta-hexosaminidase A helps break down a fatty substance called GM2 ganglioside.
Mutations in the HEXB gene disrupt the activity of beta-hexosaminidase A and beta-hexosaminidase B, which prevents these enzymes from breaking down GM2 ganglioside and other molecules. As a result, these compounds can accumulate to toxic levels, particularly in neurons of the brain and spinal cord. A buildup of GM2 ganglioside leads to the progressive destruction of these neurons, which causes many of the signs and symptoms of Sandhoff disease.
Because Sandhoff disease impairs the function of lysosomal enzymes and involves the buildup of GM2 ganglioside, this condition is sometimes referred to as a lysosomal storage disorder or a GM2-gangliosidosis.
How do people inherit Sandhoff disease?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about treatment for Sandhoff disease?
You may find information on treatment or management of Sandhoff disease or some of its symptoms in the links below, particularly the links for
Educational resources and Patient support.
Where can I find additional information about Sandhoff disease?
You may find the following resources about Sandhoff disease helpful. These materials are written for the general public.
- MedlinePlus - Health information
- Health Topic: Neurologic Diseases (http://www.nlm.nih.gov/medlineplus/neurologicdiseases.html)
- Health Topic: Tay-Sachs Disease (http://www.nlm.nih.gov/medlineplus/taysachsdisease.html)
- Additional NIH Resources - National Institutes of Health
- National Institute of Neurological Disorders and Stroke: Lipid Storage Diseases Fact Sheet (http://www.ninds.nih.gov/disorders/lipid_storage_diseases/detail_lipid_storage_diseases.htm)
- National Institute of Neurological Disorders and Stroke: Sandhoff Disease Information Page (http://www.ninds.nih.gov/disorders/sandhoff/sandhoff.htm)
- Educational resources - Information pages
- Ask the Geneticist: Genetic counseling and testing for Sandhoff disease (http://www.genetics.emory.edu/ask/question.php?question_id=3607)
- Madisons Foundation (http://www.madisonsfoundation.org/index.php/component/option,com_mpower/diseaseID,519/)
- Orphanet (http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=796)
- Patient support - For patients and families
- Children Living with Inherited Metabolic Diseases (CLIMB) (UK) (http://www.climb.org.uk/)
- Hide and Seek Foundation for Lysosomal Disease Research (http://www.hideandseek.org/index.php?option=com_content&task=view&id=110&Itemid=75)
- March of Dimes (http://www.marchofdimes.com/pnhec/4439_1227.asp)
- National Organization for Rare Disorders (http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Sandhoff+Disease)
- National Tay-Sachs and Allied Diseases Association (http://www.ntsad.org/)
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for Sandhoff disease?
- Beta-hexosaminidase-beta-subunit deficiency
- GM2 gangliosidosis, type 2
- GM2 Gangliosidosis, Type II
- Hexosaminidase A and B Deficiency Disease
- Sandhoff-Jatzkewitz-Pilz disease
- Total hexosaminidase deficiency
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
What if I still have specific questions about Sandhoff disease?
- See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
- Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).
- Submit your question to Ask the Geneticist (http://www.askthegen.org/).
What glossary definitions help with understanding Sandhoff disease?
ataxia ;
autosomal ;
autosomal recessive ;
cell ;
compound ;
deficiency ;
enzyme ;
gene ;
lipid ;
lysosome ;
mental illness ;
molecule ;
motor ;
motor skill ;
mutation ;
nerve cell ;
nervous system ;
neuron ;
organomegaly ;
population ;
protein ;
recessive ;
seizure ;
sign ;
subunit ;
symptom ;
toxic
You may find definitions for these and many other terms in the Genetics Home Reference
Glossary (http://ghr.nlm.nih.gov/glossary).
References
- Hendriksz CJ, Corry PC, Wraith JE, Besley GT, Cooper A, Ferrie CD. Juvenile Sandhoff disease--nine new cases and a review of the literature. J Inherit Metab Dis. 2004;27(2):241-9. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=15159655)
- Tay SK, Low PS, Ong HT, Loke KY. Sandhoff disease--a case report of 3 siblings and a review of potential therapies. Ann Acad Med Singapore. 2000 Jul;29(4):514-7. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=11056783)
- Yoshizawa T, Kohno Y, Nissato S, Shoji S. Compound heterozygosity with two novel mutations in the HEXB gene produces adult Sandhoff disease presenting as a motor neuron disease phenotype. J Neurol Sci. 2002 Mar 30;195(2):129-38. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=11897243)
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
healthcare professional.
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
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