What is Tay-Sachs disease?
Tay-Sachs is a rare, genetic metabolic condition which affects how the brain and nervous system work. It happens because of a build-up of fatty material in nerve cells which makes it harder for them to work as they should. It is usually diagnosed in babies causing changes in development and sensory challenges.
Sometimes Tay-Sachs won’t show symptoms until teens, or early adulthood – which is known as late onset Tay-Sachs (LOTS). This form progresses more slowly and symptoms are often milder.
There is no cure for either form of Tay-Sachs, but medicines and continued care aim to improve quality of life.
What causes Tay-Sachs disease?
Tay-Sachs is caused by a gene change affecting how the hexosaminidase A (Hex-A) enzyme is made. This enzyme is responsible for breaking down fatty material in our bodies and without it working properly, it builds up in nerve cells, particularly in the brain and spinal cord.
If the Hex-A enzyme is missing completely the condition usually develops early in life. If the enzyme is present, but doesn’t work as it should, symptoms may not develop until teens or early adulthood and will be milder.
Tay-Sachs is inherited in an autosomal recessive pattern, which means that two copies of the altered gene are needed for the condition to develop. Members of the same family may carry the gene, without showing symptoms themselves.
What are the symptoms of Tay-Sachs disease?
The symptoms of Tay-Sachs will vary depending on the stage of life they appear.
Infantile Tay-Sacs
- Exaggerated startle reflex – being unusually sensitive to loud noises
- Loss of learned skills – such as sitting or crawling
- Changes in movement – including muscle weakness, stiffness and reduced movement
- Hearing and vision problems – being less responsive to sights and sounds
- Difficulty swallowing – including problems with feeding
- Seizures – as the condition progresses
- Cherry-red spot in the eyes – a typical feature that doctors look out for during diagnosis
Late onset Tay-Sachs
- Problems with muscle control – affecting balance and co-ordination
- Slurred speech – speech may be slower or harder to understand
- Muscle cramps and weakness – including sore muscles that tire more easily
- Memory problems – difficulties with remembering or concentrating
- Low mood – feeling sad or anxious
- Difficulty swallowing – affecting eating and drinking
As symptoms of late onset Tay-Sachs progress slowly, the condition can be harder to recognise. Early signs such as clumsiness or low mood can be mistaken for other conditions, so it’s important to get these symptoms checked.
