Late onset Tay-Sachs disease is a neurodegenerative condition that runs in families. This form of Tay-Sachs disease progresses slower than other forms and doesn’t typically shorten your life expectancy.
Tay-Sachs disease is a rare genetic condition that affects the body’s nerves. There are three main forms of the condition:
- the infantile form
- the juvenile form
- the late onset form
Each form has its own age of onset and rate of progression.
Here’s what you should know about late onset Tay-Sachs (LOTS) disease, including when symptoms may start and what the outlook is in the long term.
LOTS is a form of Tay-Sachs disease that starts when a person is in their late teenage years or older. Some people may have disease onset in their 20s, while others may not have symptoms until their 60s or 70s.
The condition is due to a mutation in the HEXA gene. HEXA is responsible for producing an enzyme called hexosaminidase A.
People with LOTS have some enzyme activity, but, over time, hexosaminidase A deficiency causes fats to build up in the brain and nerve cells. It’s this buildup of fats that causes progressive issues in the nervous system and, therefore, symptoms.
You may walk unsteadily (balance and gait issues) and have symptoms of progressive neurological deterioration, which may include:
- psychiatric issues
- muscle twitching
- muscle cramps
- slurred speech
- trouble swallowing
- memory issues
Since people with LOTS have some enzyme activity, symptoms tend to be less severe and slower to progress than in the more common infantile form. That form is due to a total lack of enzyme activity.
If you have a known family history of Tay-Sachs disease, genetic testing is another possibility. To do this, a doctor will take blood and look for mutations in the HEXA gene.
There’s currently no cure for LOTS. Treatment aims to reduce your symptoms and improve your quality of life. As a result, there’s no standard treatment that works for everyone.
Treatment may include:
With LOTS, you may have trouble walking and have other motor movement issues that get worse over time. You may need assistive devices like a walker or wheelchair to get around.
Other complications include trouble speaking, which may lead to communication issues, and trouble swallowing, which may lead to aspiration and infection.
Family history is the
- people of Ashkenazi Jewish descent
- Old Older Amish individuals in Pennsylvania
- French-Canadian people who live near the St. Lawrence River
- Cajun people in Louisiana
Tay-Sachs disease is heritable in an autosomal recessive manner. This means that you need to inherit two genes, one from each parent, to develop the condition.
According to the National Health Service (NHS) of the United Kingdom, if two carriers of the affected gene have a child, the risk is:
- 25% that the child won’t have the condition or be a carrier
- 50% that the child won’t have the condition but will be a carrier of the affected gene
- 25% that the child will have the condition
While rates of Tay-Sachs disease are higher in certain populations, the carrier rate in the general population is around 1 in 250–300 people.
While LOTS can interfere with your movement, feeding and swallowing, and mental health, it doesn’t typically shorten your life expectancy.
People with LOTS will need to work with a team of healthcare professionals (HCPs) in different specialties to treat their individual needs as the condition progresses. These HCPs may include:
Here are some frequently asked questions about LOTS.
How rare is late onset Tay-Sachs disease?
When do symptoms of Tay-Sachs disease usually start?
The onset of symptoms depends on the form of Tay-Sachs disease a person has. According to the National Organization for Rare Disorders, it’s as follows:
- 3–6 months old for individuals with the infantile form
- 2–10 years old for individuals with the juvenile form
- anytime after the late teenage years for individuals with the late onset form
What other conditions may be confused with LOTS?
People with LOTS may not know they have it until later on in life. Even people within the same family don’t always develop LOTS symptoms at similar ages. Onset, symptom severity, and progression are individual and depend on the amount of enzyme activity in the body.
If you have a family history of Tay-Sachs disease, consider making an appointment with your doctor for genetic testing. While you may not have the condition itself, you could be a carrier and pass it on to your children.