Tay-Sachs and Sandhoff diseases
Tay-Sachs and Sandhoff diseases are rare, inherited diseases that affect a baby’s central nervous system (the brain and spinal cord). The central nervous system controls how the body works.
Sandhoff disease is a severe form of Tay-Sachs. Babies with Tay-Sachs have none or not enough of an enzyme (protein) called hexosaminidase A. Babies with Sandhoff disease have no hexosaminidase A and hexosaminidase B enzymes. Both enzymes break down fatty substances in cells, including brain cells. Without enough of these enzymes, fatty substances build up and slowly destroy brain cells, until the nervous system stops working.
Over time, Tay-Sachs and Sandhoff diseases cause nerve cells in the brain and spine to die. Some forms of each disease can affect babies and cause death. About 16 people are diagnosed with Tay-Sachs disease each year in the United States.
What causes Tay-Sachs and Sandhoff diseases?
Both diseases are passed from parent to child through genes. A gene is a part of your body’s cells that stores instructions for the way your body grows and works. Genes come in pairs—you get one of each pair from each parent.
Sometimes the instructions in genes change. This is called a gene change or a mutation. Parents can pass gene changes to their children. Sometimes a gene change can cause a gene to not work correctly. Sometimes it can cause birth defects or other health conditions.
You have to inherit a gene change from both parents to have these diseases. If you inherit the gene change from just one parent, you have the gene change but not the disease. When this happens, you’re called a carrier. A carrier has the gene change but doesn’t have the disease.
If you and your partner both carry the gene change for Tay-Sachs, your baby may get two gene changes (one from each of you) and have the disease. It works the same way for Sandhoff disease. If both you and your partner are carriers (you both have the gene change), there is:
- A 1-in-4 chance (25 percent) that your baby can have the disease
- A 1-in-4 chance (25 percent) that your baby won’t have the disease and won’t be a carrier
- A 1-in-2 chance (50 percent) that your baby won’t have the disease but will be a carrier
If a blood tests shows that you or your partner is a carrier for Tay-Sachs or Sandhoff disease, you may want to meet with a genetic counselor. This is a person who is trained to help you understand how genes, birth defects and other medical conditions run in families, and how they can affect your health and your baby’s health.
Are some babies more likely to have these diseases than others?
Yes. Tay-Sachs is more common in people from certain ethnic groups. An ethnic group is a group of people, often from the same country, who share language or culture.
Tay-Sachs is more common in these ethnic groups:
- Central and Eastern European Jewish (also called Ashkenazi Jews)
- French-Canadian groups in Quebec, Canada
- Louisiana Cajun
- Old Order Amish of Pennsylvania
Sandhoff disease isn’t as strongly linked to ethnic groups as Tay-Sachs. It’s rare among Jewish people and seems to be more common in these groups:
- Creole of northern Argentina
- Metis Indians in Saskatchewan, Canada
If you or your partner is part of these ethnic groups, or you have a family history of Tay-Sachs disease or Sandhoff disease, tell your health care provider. You and your partner can have a blood test to see if you carry the gene mutation that causes these diseases.
How do you know if your baby has Tay-Sachs or Sandhoff disease?
Your health care provider may use prenatal tests to diagnose Tay-Sachs or Sandhoff disease before birth. Prenatal tests are medical tests you get during pregnancy. They help your provider find out how you and your baby are doing. Your provider may use these prenatal tests to diagnose Tay-Sachs or Sandhoff diseases:
- Amniocentesis (also called amnio). This this test takes some amniotic fluid from around your baby in the uterus. The test checks for birth defects and genetic conditions in your baby. You can get this test at 15 to 20 weeks of pregnancy.
- Chorionic villus sampling (also called CVS). This test checks tissue from the placenta to see if a baby has a genetic condition, like Tay-Sachs or Sandhoff disease. You can get CVS at 10 to 12 weeks of pregnancy.
If your baby develops problems hearing, seeing or moving after birth, your baby’s provider may use a physical exam and blood tests to diagnose the diseases.
Are there different types of each disease?
Yes. They’re named depending on when the disease affects a person. The classic (also called infantile) type affects babies and is the most common type of each disease. The juvenile type starts during childhood. Other types of these diseases are less common, but may affect older children, teens or adults.
Classic Tay-Sachs and classic Sandhoff diseases. These diseases affect a baby when he’s young. Babies with classic Tay-Sachs disease usually die by the time they’re 4 years old. Babies with classic Sandhoff disease usually die by the time they’re 3 years old.
A baby with classic Tay-Sachs or classic Sandhoff disease starts to develop normally in the first few months of life. Signs and symptoms of the disease usually appear by about 6 months, when the baby slowly stops smiling, crawling, turning over and reaching out. Your baby’s health care provider may see cherry-red spots in your baby’s eye during an eye exam.
Over time, a baby continues to lose skills and develops other health problems, including:
- Breathing problems
- Hearing loss
- Intellectual disabilities. These are problems with how the brain works that can cause a person to have trouble or delays in physical development, learning, communicating, taking care of himself or getting along with others.
- Paralysis. This is when you can’t feel or move one or more parts of your body.
- Seizures. This is when the whole body or parts of the body move without control.
- Swallowing problems
- Vision loss, leading to blindness
Juvenile Tay-Sachs and juvenile Sandhoff diseases. These diseases can begin anytime during childhood. Children with these conditions usually die by the time they’re 15 years old. They usually show signs or symptoms when they’re 2 to 5 years old, including:
- Being clumsy
- Having slurred speech
- Having weak muscles or muscle cramps
Over time, these children have more health problems. They eventually can’t walk, eat by themselves or communicate. They may have seizures and may be more likely than other children to get lung infections, like pneumonia.
Are there any treatments for Tay-Sachs and Sandhoff diseases?
There is no cure for these diseases, but medicines and healthy eating can help manage them. Medicines can treat pain, seizures and twitching muscles. Some children need a feeding tube, a small, soft, plastic tube placed through the nose or mouth into the stomach. You can give food and medicine to your baby through the tube when she can’t take them by mouth.
National Tay-Sachs and Allied Disease Association
Last reviewed May 2014
See also: Genetic counseling
Frequently Asked Questions
Can dad's exposure to chemicals harm his future kids?
Dad's exposure to harmful chemicals and substances before conception or during his partner's pregnancy can affect his children. Harmful exposures can include drugs (prescription, over-the-counter and illegal drugs), alcohol, cigarettes, cigarette smoke, chemotherapy and radiation. They also include exposure to lead, mercury and pesticides.
Unlike mom's exposures, dad's exposures do not appear to cause birth defects. They can, however, damage a man's sperm quality, causing fertility problems and miscarriage. Some exposures may cause genetic changes in sperm that may increase the risk of childhood cancer. Cancer treatments, like chemotherapy and radiation, can seriously alter sperm, at least for a few months post treatment. Some men choose to bank their sperm to preserve its integrity before they receive treatment. If you have a question about a specific exposure, contact the Organization of Teratology Information Specialists at www.otispregnancy.org.
Can Rh factor affect my baby?
The Rh factor may be a problem if mom is Rh-negative but dad is Rh-positive. If dad is Rh-negative, there is no risk.
If your baby gets her Rh-positive factor from dad, your body may believe that your baby's red blood cells are foreign elements attacking you. Your body may make antibodies to fight them. This is called sensitization.
If you're Rh-negative, you can get shots of Rh immune globulin (RhIg) to stop your body from attacking your baby. It's best to get these shots at 28 weeks of pregnancy and again within 72 hours of giving birth if a blood test shows that your baby is Rh-positive. You won't need anymore shots after giving birth if your baby is Rh-negative. You should also get a shot after certain pregnancy exams like an amniocentesis, a chorionic villus sampling or an external cephalic version (when your provider tries to turn a breech-position baby head down before labor). You'll also want to get the shot if you have a miscarriage, an ectopic pregnancy or suffer abdominal trauma.
Does cleft lip or cleft palate cause dental problems?
A cleft lip or cleft palate that extends into the upper gums (where top teeth develop) can cause your baby to have certain dental problems, including:
- Missing teeth
- Too many teeth
- Oddly shaped teeth
- Teeth that are out of position around the cleft
Every baby with a cleft lip or palate should get regular dental checkups by a dentist with experience taking care of children with oral clefts. Dental problems caused by cleft lip or palate usually can be fixed. If needed, your baby can get ongoing care by a team of experts, including:
- A dentist
- An orthodontist to move teeth using braces
- An oral surgeon to reposition parts of the upper jaw, if needed, and to fix the cleft
See also: Cleft lip and cleft palate
Does cleft lip or cleft palate cause ear problems?
Cleft lip does not cause ear problems.
Babies with cleft palate, however, are more likely than other babies to have ear infections and, in some cases, hearing loss. This is because cleft palate can cause fluid to build up in your baby’s middle ear. The fluid can become infected and cause fever and earache. If fluid keeps building up with or without infection, it can cause mild to moderate hearing loss.
Without treatment , hearing loss can affect your baby’s language development and may become permanent.
With the right care, this kind of hearing loss is usually temporary. Your baby’s provider may recommend:
- Having your baby’s ears checked regularly for fluid buildup
- Medicines for treating fluid buildup and ear infections
- Ear tubes if your baby has fluid in his ears over and over again. Ear tubes are tiny tubes that are inserted into the eardrum to drain the fluid and help prevent infections.
See also: Cleft lip and cleft palate
Does cleft lip or cleft palate cause problems with breastfeeding?
Babies with only a cleft lip usually don’t have trouble breastfeeding. Most of the time, they can breastfeed just fine. But they may need some extra time to get started.
Babies with cleft lip and palate or with isolated cleft palate can have:
- Trouble sucking strong enough to draw milk through a nipple
- Problems with gagging or choking
- Problems with milk coming through the nose while feeding
Most babies with cleft palate can’t feed from the breast. If your baby has cleft palate, he can still get the health benefits of breastfeeding if you feed him breast milk from a bottle. Your provider can show you how to express (pump) milk from your breasts and store breast milk.
Your baby’s provider can help you start good breastfeeding habits right after your baby is born. She may recommend:
- Special nipples and bottles that can make feeding breast milk from a bottle easier
- An obturator. This is a small plastic plate that fits into the roof of your baby’s mouth and covers the cleft opening during feeding.
See also: Cleft lip and cleft palate, Breastfeeding
Does cleft lip or cleft palate cause speech problems?
Children with cleft lip generally have normal speech. Children with cleft lip and palate or isolated cleft palate may:
- Develop speech more slowly
- Have a nasal sound when speaking
- Have trouble making certain sounds
Most children can develop normal speech after having cleft palate repair. However, some children may need speech therapy to help develop normal speech.
See also: Cleft lip and cleft palate
What are choroid plexus cysts?
The choroid plexus is the area of the brain that produces the fluid that surrounds the brain and spinal cord. This is not an area of the brain that involves learning or thinking. Occasionally, one or more cysts can form in the choroid plexus. These cysts are made of blood vessels and tissue. They do not cause intellectual disabilities or learning problems. Using ultrasound, a health care provider can see these cysts in about 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several months after birth and are no risk to the baby. They aren't a problem by themselves. But if screening tests show other signs of risk, they may indicate a possible genetic defect. In this case, testing with higher-level ultrasound and/or amniocentesis may be recommended to confirm or rule out serious problems.
What if I didn't take folic acid before pregnancy?
If you didn’t take folic acid before getting pregnant, it doesn't necessarily mean that your baby will be born with birth defects. If women of childbearing age take 400 micrograms of folic acid every day before and during early pregnancy, it may help reduce their baby’s risk for birth defects of the brain and spin called neural tube defects (NTDs). But it only works if you take it before getting pregnant and during the first few weeks of pregnancy, often before you may even know you’re pregnant.
Because nearly half of all pregnancies in the United States are unplanned, it's important that all women of childbearing age (even if they're not trying to get pregnant) get at least 400 micrograms of folic acid every day. Take a multivitamin with folic acid before pregnancy. During pregnancy, switch to a prenatal vitamin, which should have 600 micrograms of folic acid.
Last reviewed November 2012