There are multiple forms of Tay-Sachs disease but the most common form is seen during infancy. Babies with Tay-Sachs disease appear healthy at birth. However, at three to six months of age, an affected baby will begin to lose developmental skills and experience progressive weakness, loss of motor skills, increased startle response and myoclonic jerks. A cherry red spot can appear in the eye. Gradually the child begins to lose visual attentiveness, has decreased voluntary movements and responsiveness, develop seizures and intellectual disability. The disease progresses rapidly until the child becomes completely unresponsive.
Symptoms in the juvenile form of Tay-Sachs typically appear between the ages of 2 and 5, but can occur anytime during childhood. Early symptoms include lack of coordination or clumsiness. Children may also have slurred speech, swallowing issues and muscle cramps. Over time, children will slowly decline and lose developmental and motor skills until the child becomes completely unresponsive.
Late-onset Tay-Sachs disease is caused by mutations in the same gene as classical infantile Tay-Sachs disease, but because an individual’s body retains some enzyme activity, the disease is less severe, though still difficult. Symptoms typically appear in adolescence or early adulthood, but can also appear later in life. Adults with late-onset Tay Sachs may also present with mental health symptoms such as bipolar or psychotic episodes. Over time adults with late onset Tay Sachs slowly decline and can require more mobility assistance. Many may also experience speech and swallowing difficulties.
A laboratory test checks for a lack of hex A enzymatic activity. Genetic testing can also check for relevant mutations in the hex A gene. Both are done through a simple blood test.
There is no effective treatment or cure for Tay-Sachs disease at this time. Supportive care is aimed at providing the affected child with comfort. Research is making advances toward a treatment and cure, and potential therapies are under investigation.
For individuals with classic/infantile Tay-Sachs disease, death usually occurs by two to four years of age from bronchopneumonia.
Genetic testing can reveal approximately 98% of relevant mutations in the hex A gene in the Ashkenazi Jewish population. The Center encourages prospective parents to meet with a genetic counselor and get tested before conception, in order to make the best health care decisions for their family.
DNA testing is available to those with a previously affected child or to couples found to be at risk as carriers.