Tay-Sachs Disease Life Expectancy

Tay-Sachs disease (also sometimes referred to as infantile Tay-Sachs disease) is a condition characterized by the slow degeneration of nerve cells. In turn, this leads to decreased mental, physical and cognitive abilities over time.

It is thought that this condition is the result of an excess production of gangliosides (components of cellular membranes) that subsequently migrate to the neuron cells within the brain. Tay-Sachs disease is also caused by a lack of the HEXA enzyme and newer mutations are still being discovered as research advances. Although there is no currently known treatment or cure, the life expectancy will vary depending upon when the illness first presents itself.

Classic (Infantile) Tay-Sachs Disease

It should first be noted that infantile Tay-Sachs disease is normally present when the fetus is developing. However, it is difficult to detect any symptoms until after birth. In regards to this variant, infants will appear to develop normally during their first six months. This is then followed by the slow and yet noticeable deterioration of physical and mental capabilities. In some cases, a condition known as the "startle response" will occur as a result of hypersensitivity to sudden touches or sounds.

As the neurons become distended from their gangliosides, the condition of the infant will continue to worsen. He or she may suffer from other conditions such as blindness, paralysis, muscular atrophy and the inability to swallow. As the brain is still in its earliest forms of development, prognosis is generally poor. The infant will usually die before four years of age.

Juvenile Onset

This is the rarest form of Tay-Sachs disease. Initial symptoms will normally present themselves between the ages of two and ten. It is thought that a slight production of the aforementioned HEXA enzyme slows the overall progression of the illness. This is why the symptoms tend to develop a bit later in life and the progression is somewhat slower. A steady decline in cognitive skills, poor motor coordination, speech problems and ataxia are a handful of conditions that will result from this rare variant.

However, it should still be noted that life expectancy is limited. Those who are diagnosed with juvenile Tay-Sachs disease can (normally) expect a lifespan of no more than 15 years.

Late Onset

Also referred to as adult-onset Tay-Sachs disease, overt symptoms will normally begin between the ages of 30 and 40. Some circles refer to this variant as "chronic" Tay-Sachs disease. It is interesting to note that while a positive diagnosis may occur between 30 and 40 years of age, some believe that the initial symptoms will begin as far back as early adolescence.

Some of the conditions associated with late-onset Tay-Sachs include memory and comprehension problems, slurred speech, muscle atrophy, an unsteady gait and even mental illness. However, we should note here that blindness and deafness will normally not occur (as opposed to the two other forms). It is still not uncommon for sufferers to be confined to a wheelchair for the remainder of their adult lives.

One of the issues with the prior diagnosis of this form was that in the past, its molecular genetics were not fully understood. It is for this reason that late-onset Tay-Sachs was often confused with outwardly similar conditions such as Freidrich's ataxia and Sandhoff disease.

The life expectancy of those suffering from late-onset Tay-Sachs disease can vary. In fact, the majority of cases are not fatal in and of themselves and their lifeline seems to be relatively unaffected. This arises from the fact that the disease will stop progressing.

Comorbidity Issues

Finally, we must take into account concurrent conditions which may impact the life expectancy of those with Tay-Sachs disease; particularly the late-onset variety. A lack of mobility, a decreased immune system and poor diet can all be factors which will limit one's lifespan.

As there are no known treatments, such issues need to be taken into account to make certain that the patient will not suffer from secondary illnesses which may lead to a premature death. It is hoped that future genetic research will shed light on potential treatment options from both genetic and pharmacological perspectives.