Healthy infants tend to achieve their growth and development milestones in a timely manner. They also develop their vision, hearing, movement, and other types of vital functions because certain enzymes clear out fatty protein as well as other unwanted elements that can hinder normal growth.
However, an infant with Tay-Sachs disease lack those needed enzymes, so fatty proteins accumulate in the nerve cells and affect the infant’s mental development, sense of sight, hearing, and movements.
What is Tay-Sachs disease?
Tay Sachs disease is a rare inherited disorder that affects the central nervous system (CNS) of an individual. It is a neurodegenerative disorder that is commonly seen in infants or small children. It is known to be a progressive disease that can lead to death. Aside from infants, Tay Sachs disease can also affect adults or teens but with less severe symptoms. However, such occurrences are quite rare.
Most infants with this medical condition tend to have nerve damage, which usually starts in utero or prior to birth. The symptoms would start to appear from the age of 3-6 months. Most of the time, the progression of the disease is quite fast and children would typically pass away when they reach the age of 4-5 years old. Below are some of the symptoms that can be seen in an infant with Tay-Sachs disease:
- Reduced muscle strength
- Unable to hear or deafness
- Seizure attacks or epilepsy
- Progressive blindness
- Loss of muscle functioning or paralysis attack
- Slow growth when compared to other infants
- Has a high startle response
- Cherry-red spot on the macula
- Stiffness in the muscles or spasticity
- Poor social and mental development
A baby born with this medical condition would normally develop during the first 3-6 months of life. However, during the next few months or even years, babies would progressively start to lose their ability to hear, move, and see anything.
There would also be a presence of a red spot that would develop in the back of their eyes. Children would slowly change their behavior, wherein they would stop smiling, crawling, reaching out for something, or turning over. By the time they reach the age of 2, they may start having seizure attacks and would become completely disabled. In such scenarios, death mostly occurs by the time they reach the age of 5.
It is important to seek immediate medical help in case the child experiences a seizure attack or when having breathing difficulties.
Some may have other forms of the disorder, which include late-onset juvenile, adult, and chronic. However, they tend to be rarer, milder, and less severe.
- Late-onset Juvenile - Individuals who have the juvenile form are most likely to show symptoms between the ages 2-10 years old and usually pass away by the time they reach 15.
- Chronic - Those who have the chronic form of the disease tend to develop symptoms by the time they reach the age of 10. However, the disease tends to progress very slowly. Few of its symptoms may include muscle cramps, tremors, and speech problems. Some individuals may even live a normal lifespan.
- Adult - Symptoms usually show during teenage years to adulthood. Individuals who have the adult form of the disease usually experience symptoms of speech and memory problems, muscle weakness, tremors, and walking abnormalities.
The cause of this medical condition is a defective gene on chromosome 15 (HEX-A). This defective gene is known to cause the body not to make enough of a protein called hexosaminidase A. Without this particular protein, complex glycolipids called gangliosides tend to build up in the nerve cells and destroy them.
This disease is genetically inherited. An individual has to receive two copies of defective genes, which would be one from each parent. If only one parent passed down a defective gene, then the child would become a carrier. In such cases, they would not get affected but may pass down the medical condition to their children.
The disorder is seen to be quite common among the Ashkenazi Jews, whose families descended from the Jewish communities based in the Central or Eastern European regions. According to research, it has been reported that an estimated 1 in 30 people who are American Ashkenazi Jews are carriers of the disorder.
Since the disease is hereditary, there is no way to prevent the disease from occurring. However, there are various screenings available or genetic testing being carried out to see if you are a potential carrier or if the fetus has this disease. In case if you or your partner is said to be a carrier, then genetic testing would help in making the decision whether you would need to have children or not.
Every year in the United States, there are about 16-20 Tay-Sachs disease cases being reported. In certain cases, few of the individuals do carry this type of genetic mutation, but they do not in any way develop a full blown disease. In case if both carrier parents have a child together, their child would have:
- 50 percent chance of becoming a carrier but not develop the disease.
- 25 percent chance of not becoming a carrier and not develop the disease.
- 25 percent chance that the child would develop the disease.
Prenatal testings are available, which would include amniocentesis and chorionic villus sampling (CVS). These tests can help in the correct diagnosis of the disease before the baby is born. Genetic testing is mostly carried out when one or both parents are carriers of the disease.
The CVS prenatal testing is said to be performed when a pregnant woman is in her 10th to 12th week of pregnancy. This test involves taking a sample of cells from the placenta. This can be done via the abdomen or vagina.
Amniocentesis can be carried out when a pregnant woman is in her 15th to 20th week of pregnancy. It would involve extracting a sample of fluid that surrounds the fetus using a needle through the abdomen of the mother.
If the child is showing or displaying any symptoms of the disease, then the doctor would first perform a physical examination of the child, and at the same time, would try to collect information and understand the family's medical history. The doctor can also order an enzyme analysis by taking tissue or blood samples of the child. An eye examination can also be performed to check the presence of a red spot on the child's macula.
There is still no cure for Tay-Sachs disease. Usually, treatment consists of trying to keep the child as comfortable as possible. This is known as palliative care. Treatment also includes medications for pain, anticonvulsants to control seizure attacks, feeding tubes, physical therapy, and respiratory care to reduce the buildup of mucus present in the lungs.
A lot of emotional support is required from the family. It would also be useful to seek out support groups. It is a very challenging process to look after a sick child, which at times can be quite draining. Talking and sharing your family's experiences with other families who are also going through the same situation can be comforting.
Support and Care
As previously mentioned, this disease has no cure. However, doctors are able to help the child cope with the symptoms by prescribing medications for pain relief, better management of seizure attacks, and muscle spasticity.
There are still ongoing research studies to find ways of improving the treatment and screening of Tay-Sachs disease. If you are planning to start a family and suspect that you or your partner might be carriers of the disease, talk to a genetic counselor.