Topic Overview
What is Tay-Sachs disease?
Tay-Sachs is a rare
disease that is passed down through some families. It harms the brain and nerve
cells. There are two forms:
- The most common form develops soon after a
baby is born. The child usually lives for 4 or 5 years.
-
Late-onset Tay-Sachs
can start between
puberty and the mid-30s. How long a person lives
depends on how severe the symptoms are. People may live as long as someone who
does not have Tay-Sachs disease.
What causes Tay-Sachs disease?
Tay-Sachs can occur
when parents pass on a changed (mutated)
gene to their child.
- If a baby gets the gene from both parents, he
or she will get the disease.
- If the baby gets the gene from only
one parent, he or she will be a
carrier. This means that the child will carry the
changed gene but will not have the disease.
The changed gene keeps your body from making an
enzyme called hexosaminidase A (hex A). Hex A breaks
down normal fatty compounds (called gangliosides) in cells. When these fatty
compounds are not broken down, they build up and damage brain and nerve cells,
causing Tay-Sachs disease.
In late-onset Tay-Sachs (LOTS), the body
makes a small amount of hex A. People with LOTS inherit the late-onset hex A
gene from both parents or inherit one late-onset gene and one inactive gene.
The Tay-Sachs gene is most common in people of Ashkenazi Jewish
descent. About 1 out of 30 people in this population is a carrier of the
disease.1 People of
French-Canadian descent from the East Saint Lawrence River Valley of Quebec and
people of Cajun descent in Louisiana are also more likely to carry the gene
than others.
What are the symptoms?
A child with Tay-Sachs
disease looks healthy at birth. But when your child is:
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3 to 6 months of age,
you may notice that your child makes less eye contact and has a hard time
focusing his or her eyes on things. A doctor may see a red spot on your child's
retina.
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6 to 10 months of age, you may notice that your child is not as alert and playful as he
or she had been. It might be hard for your child to sit up or roll over. You
also may notice that your child does not see or hear well.
-
10 months and older, the disease gets worse quickly. Your
child may have
seizures, lose his or her vision, and not be able to
move.
In late-onset Tay-Sachs (LOTS), early symptoms such as
clumsiness or mood changes may be minor or seem “normal” and go unnoticed.
Later symptoms may include muscle weakness and twitching, slurred speech, and
trouble thinking and reasoning. The symptoms depend on how much hex A the body
makes.
How is Tay-Sachs disease diagnosed?
If you or your
doctor thinks your child has Tay-Sachs disease, your doctor will do a physical
exam and a blood test to check the level of hex A. A genetic test may be needed
to be sure the disease is Tay-Sachs.
How is it treated?
The focus of treatment for
Tay-Sachs disease is to control symptoms and make your child as comfortable as
possible. There is no cure. It may be helpful to seek counseling or find
support from others who are going through the same thing you are.
If you develop late-onset Tay-Sachs disease (LOTS), treatment also
focuses on controlling symptoms. The treatment you receive, such as medicine
for
depression, depends on the symptoms you have.
It may be overwhelming to learn that your child has Tay-Sachs. It’s
important that you care for yourself as well as your child. Talk to your doctor
about:
- Your concerns and the help you'll need for
your child.
- A support group in your area.
- Family
counseling to help each member cope with the disease.
As the disease gets worse, your child will need more care.
Encourage your child to be as active as possible for as long as possible. Give
your child your love and affection.
You may not be able to care
for your child without help. Talk with your doctor about groups that can help
you.
Should you get tested?
Carriers of the Tay-Sachs
disease can pass the gene to their children even if the carriers don't have the
disease. If both you and your partner are carriers, there is a 1-in-4 chance
(25%) that any child you have will have Tay-Sachs disease.
If you
are thinking about having a child, the American College of Obstetricians and
Gynecologists (ACOG) recommends that:2
-
Both of you be
screened if you are both of Ashkenazi Jewish, French-Canadian, or Cajun descent
or have a
family history of the disease. If both of you test
positive as carriers,
genetic counseling may help you with making
choices.
- You or your partner be screened if
either of you is of Ashkenazi Jewish, French-Canadian, or Cajun descent or has
a family history of the disease. If one of you tests positive for being a
carrier, the other partner should be screened.
Frequently Asked Questions
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Learning about Tay-Sachs disease:
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Being diagnosed:
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Getting treatment:
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Ongoing concerns:
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Living with a child who has Tay-Sachs:
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End-of-life issues:
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Symptoms
A baby with
Tay-Sachs disease has no signs or symptoms of the
disease at birth. Symptoms usually appear 3 to 6 months after birth. The
symptoms are caused by damage to the brain and nerve cells from the buildup of
fatty compounds. An early sign of the infantile form of Tay-Sachs is a red spot
on the
retina.
Watch for the following symptoms
if you suspect your baby may have Tay-Sachs disease.
At 3 to 6 months, you may notice:
- Decreased eye contact.
- Twitchy
eyes (myoclonic jerks).
- Difficulty focusing on
objects.
- Excessive startling by sharp but not necessarily loud
noises.
At 6 to 10 months, you may notice:
- Limp and floppy muscles
(hypotonia).
- Decreased alertness and
playfulness.
- Difficulty sitting up or rolling over and a loss of
motor skills.
- Decreased hearing and
eventual deafness.
- Gradual loss of vision.
- An abnormal
increase in head size (macrocephaly).
10 months and older
As a child with Tay-Sachs
grows older, he or she may become blind, paralyzed, and
unresponsive to the environment. The child also may have
intellectual disability, seizures, difficulty swallowing, and difficulty
breathing. Children with Tay-Sachs disease rarely live beyond 4 or 5 years of
age.
Late-onset Tay-Sachs disease
Symptoms of
late-onset Tay-Sachs disease (LOTS) usually occur
between adolescence and the mid-30s. The symptoms vary
depending on the amount of hex A being produced by the body. At first symptoms
such as clumsiness or mood changes are subtle and may go unnoticed. Other
symptoms that may occur include:
- Personality changes.
- Muscle
weakness or twitching.
- Slurred speech.
- Impaired
thinking and reasoning ability, such as memory problems, difficulty with
comprehension, and short attention span.
- Inability to distinguish
between what's real and unreal (psychotic episodes) or
depression.
Exams and Tests
If your baby is suspected of having
Tay-Sachs disease, a physical exam may reveal
or confirm symptoms of the disease. A blood test (Tay-Sachs test) can show whether your baby's body is producing the
enzyme hexosaminidase A (hex A). The blood sample can
be taken from a vein or from the
umbilical cord immediately after birth.
If you are pregnant and are at risk for having a child with Tay-Sachs
disease, the Tay-Sachs test can be done. A blood sample is collected
from the
placenta during
chorionic villus sampling, or a sample of amniotic
fluid is collected during
amniocentesis. For more information, see the topics
Amniocentesis and
Chorionic Villus Sampling.
The Tay-Sachs
test is also used to confirm
late-onset Tay-Sachs disease in a teen or adult who has symptoms of the disease.
A positive Tay-Sachs test may need to be
confirmed with other genetic tests.
Screening for carriers
Knowing whether you are a
carrier of Tay-Sachs disease is important because
Tay-Sachs is an
autosomal recessive disease. If you are a carrier, you have one
gene that produces hex A and one that does not produce
this
enzyme. Your body makes enough hex A so that you don't get the disease. But you can
pass the gene on to your children. If both you and your partner are carriers,
there is a 1-in-4 chance (25%) that any child you have will have Tay-Sachs
disease.
If you are thinking about having a child, the American
College of Obstetricians and Gynecologists (ACOG) recommends that:2
-
Both prospective parents be tested if both
of you are Ashkenazi Jews or of French-Canadian or Cajun descent or have a
family history of the disease. If both of you test positive as carriers, you
should consider
genetic counseling.
- You or your partner be tested if either of you is an Ashkenazi
Jew or of French-Canadian or Cajun descent or has a family history of the
disease. If one of you tests positive for being a carrier, the other partner
should be tested.
Either hex A testing or
DNA testing can be done.
In Ashkenazi
Jews:2
- DNA testing detects 94 out of 100 carriers.
- Hex A
testing detects 98 out of 100 carriers.
Treatment Overview
Treatment is aimed at controlling
symptoms. For example, your child may take medicine for
seizures. There is no cure for
Tay-Sachs disease.
Treatment for classical or infantile Tay-Sachs disease
If your baby has Tay-Sachs disease, other support measures may be needed
as the disease progresses, such as:
- Family counseling to help family members cope
with the disease and prepare for the loss of the child. For more information,
see the topic
Grief and Grieving.
- Help with the child's
care (respite care or home health care) as the child's condition gets
worse.
- A support group to share experiences with other families who
are dealing with Tay-Sachs disease.
Treatment for late-onset Tay-Sachs disease
Treatment for
late-onset Tay-Sachs disease (LOTS) also focuses on
controlling symptoms. This form of the disease was recognized only recently, so
not much is known about its course. But it is known that the nervous system
effects get progressively worse over time. The treatment you receive, such as
medicine for
depression, depends on the symptoms you have.
You may need individual counseling to help control any behavioral or
mental disorders that develop. Your family may need family counseling to cope
with the disease and its effects. Although you may live as long as other people
who do not have Tay-Sachs disease, you still need to have a
living will and
durable power of attorney. For more information, see
the topics Writing an Advance Directive and Care at the End of Life.
What To Think About
An animal study has used gene
transfer to try to correct the gene defect. When hex A enzyme is put in the brain, it moves to the rest of the
body where it is needed.3 Although early, this
study and future studies may offer hope for Tay-Sachs disease treatment.
Talk to your doctor for information about
clinical trials and other research that is taking
place.
Home Treatment
Home treatment for
Tay-Sachs disease consists of providing comfort and
preparing for the course the disease will take.
If your child has
Tay-Sachs disease, talk with your doctor about:
- Your concerns and the guidance you need to deal
with your child.
- Whether there is a support group in your area.
Talking with other families dealing with Tay-Sachs disease may be very helpful.
- The chances that a child you have in the future will have the
disease. You and your partner may need
genetic counseling.
- Family counseling to
help each member deal with the effects of the disease.
As your child with Tay-Sachs disease becomes more ill, he or she will need more care. Encourage your child to be as
active as possible for as long as possible. Give your child the love and
affection you would give to any child. Your child will be as responsive and
active as his or her mental and physical ability allows.
Some
families find that they cannot care for their child at home without help. Talk
with your doctor about options in your community, such as respite care and
other home health services that help families care for their loved ones at
home.
As the disease progresses, it is important that you allow
yourself to grieve. For more information, see the topic
Grief and Grieving.
Late-onset Tay-Sachs disease
If you have
late-onset Tay-Sachs disease (LOTS), you may need
individual counseling to control any behavioral or mental disorders that you
develop. You and your family may need family counseling to deal with the
effects of the disease. Talk with your doctor about support groups, agencies, and
Internet resources that may be helpful for you and your family.
Although you may live as long as other people who do not have Tay-Sachs
disease, you still need to have a
living will and
durable power of attorney. For more information, see
the topics Writing an Advance Directive and
Care at the End of Life.
Other Places To Get Help
Organizations
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National Institute of Neurological Disorders and
Stroke
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| P.O. Box 5801 |
| Bethesda, MD 20824 |
| Phone: |
1-800-352-9424
(301) 496-5751 |
| TDD: |
(301) 468-5981 |
| Web Address: |
www.ninds.nih.gov |
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The National Institute of Neurological Disorders and
Stroke (NINDS), a part of the National Institutes of Health, is the leading
U.S. federal government agency supporting research on brain and nervous system
disorders. It provides the public with educational materials and information
about these disorders.
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Chicago Center for Jewish Genetic
Disorders
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| Ben Gurion Way, 30 South Wells Street |
| Chicago, IL 60606 |
| United States |
| Phone: |
312-357-4718 |
| Email: |
jewishgeneticsctr@juf.org |
| Web Address: |
www.jewishgeneticscenter.org |
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This organization provides public and professional
education about Jewish genetic disorders. It also promotes screening and
prevention programs, information, and referrals.
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Genetics Home Reference, U.S. National Library of
Medicine
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| 8600 Rockville Pike |
| Bethesda, MD 20894 |
| Phone: |
1-888-FIND-NLM (1-888-346-3656) |
| Fax: |
(301) 402-1384 |
| TDD: |
1-800-735-2258 |
| Email: |
custserv@nlm.nih.gov |
| Web Address: |
www.ghr.nlm.nih.gov |
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The Genetics Home Reference provides information on hundreds of genetic conditions. The Web site has many tools for learning about human genetics and the way genetic changes can cause
disease. It also has links to additional resources for people who
have genetic conditions and for their families.
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KidsHealth for Parents, Children, and
Teens
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| 10140 Centurion Parkway North |
| Jacksonville, FL 32256 |
| Phone: |
(904) 697-4100 |
| Fax: |
(904) 697-4220 |
| Web Address: |
www.kidshealth.org |
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This Web site is sponsored by the Nemours Foundation. It
has a wide range of information about children's health, from allergies and
diseases to normal growth and development (birth to adolescence). This Web site
offers separate areas for kids, teens, and parents, each providing
age-appropriate information that the child or parent can understand. You can
sign up to get weekly e-mails about your area of interest.
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March of Dimes
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| 1275 Mamaroneck Avenue |
| White Plains, NY 10605 |
| Phone: |
(914) 997-4488 |
| Web Address: |
www.marchofdimes.com |
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The March of Dimes tries to improve the health of babies by
preventing birth defects, premature birth, and early death. March of Dimes
supports research, community services, education, and advocacy to save babies'
lives. The organization's Web site has information on premature birth, birth
defects, birth defects testing, pregnancy, and prenatal care. You can sign up
to get a free newsletter and also explore Understanding Your Newborn: An
Interactive Program for New Parents.
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National Tay-Sachs and Allied Diseases Association, Inc.
(NTSAD)
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| 2001 Beacon Street |
| Suite 204 |
| Boston, MA 02135 |
| Phone: |
1-800-906-8723 |
| Fax: |
(617) 277-0134 |
| Email: |
info@ntsad.org |
| Web Address: |
www.ntsad.org |
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NTSAD is a nonprofit, volunteer health agency devoted to
the treatment and prevention of Tay-Sachs and other genetic conditions. Its Web
site has information about genetic diseases, carrier testing, genetic
counseling, and more. NTSAD has a support group for families and individuals
affected by genetic diseases.
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References
Citations
-
Vallance H, Ford J (2003). Carrier testing for
autosomal-recessive disorders. Clinical Laboratory Sciences, 40(4): 473–497.
-
Committee on Genetics, American College of
Obstetricians and Gynecologists (2005, reaffirmed 2007). Screening for
Tay-Sachs disease. Obstetrics and Gynecology, 106(4):
893–894.
-
Martino S, et al. (2005). A direct gene transfer
strategy via brain internal capsule reverses the biochemical defect in
Tay-Sachs disease. Human Molecular Genetics, 14(15):
2113–2123.
Other Works Consulted
- Committee on Genetics, American College of Obstetricians and Gynecologists (2009). Preconception and prenatal carrier screening for genetic diseases in individuals of Eastern European Jewish descent. Obstetrics and Gynecology, 114(4): 950–953.
- Haslam RHA (2006). Degenerative diseases of the
central nervous system. In FD Burg et al., eds., Current Pediatric Therapy, 18th ed., pp. 388–392. Philadelphia: Saunders
Elsevier.
- Neudorfer O, Kolodny EH (2004). Late-onset Tay-Sachs
disease. Israel Medical Association Journal, 6:
107–111.
- Ropper AH, Samuels MA (2009). Inherited metabolic diseases of early childhood section of Inherited metabolic diseases of the nervous system. In Adams and Victor's Principles of Neurology, 9th ed., pp. 922–926. New York: McGraw-Hill.
Credits
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By
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Healthwise Staff |
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Primary Medical Reviewer
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John Pope, MD - Pediatrics |
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Specialist Medical Reviewer
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Siobhan M. Dolan, MD, MPH - Reproductive Genetics |
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Last Revised
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March 25, 2010 |