Tay Sachs Disease

Tay Sachs Disease is a fatal autosomal recessive genetic disorder caused by an enzyme deficiency which results in fatty material being deposited in the nerve cells of the baby’s brain. Babies with the disease appear normal at birth but by six months have started to develop progressive motor weakness and mental disability which leads to blindness, deafness, the inability to swallow and severe fits. This relentless deterioration of mental and physical abilities results in the death of the infant at around three to five years of age.

There is still no cure for Tay Sachs Disease

The genetic defect is found in a single gene with one defective copy of the gene being inherited from each parent. There is no known cure or treatment for the disease but thankfully it is extremely rare. Carriers of the disease, mainly in people from Eastern Europe of Jewish descent and French Canadians, can be identified by a simple blood test before or during pregnancy. If both parents are carriers, there is a 25 per cent chance in each pregnancy of their having an affected baby.

Blood tests can be used to identify the presence of enzyme deficiency (normally carried out during your first antenatal screening) and Amniocentesis or chorionic villus sampling can be used for diagnosis of the condition. A child born unknowingly with the disease can usually be diagnosed by an eye examination, a small red dot in the retina of the eye is prevalent in all cases of Tay Sachs. The disease was named after Warren Tay who first noticed the red spot back in 1881.

There are currently many forms of research and study that are being undertaken in an effort to cure Tay Sachs but none, as yet, have passed the experimental stage. Among some of the treatments that have been investigated so far are:

    • Enzyme Replacement Therapy – This process would be similar to insulin injections for diabetics however the junctions in the blood vessels of the brain prove to be too small to enable large molecules to pass through.
    • Gene Therapy – Theoretically, if the defective gene cells could be replaced throughout the brain then Tay Sachs Disease would be cured, however, the transporting of the genes proves to be as difficult as that of the enzyme.
    • Substrate Reduction Therapy – This involves attempting to manipulate the brain’s metabolism in order to bypass the defective gene in order to metabolize it to become inconsequential.