Tay-Sachs is a genetic disorder, fatal in its most common variant known as Infantile Tay-Sachs disease. TSD is inherited in an autosomal recessive pattern. The disease occurs when harmful quantities of a fatty acid derivative called a ganglioside accumulate in the nerve cells of the brain. Gangliosides are present in lipids, which are components of cellular membranes, and the ganglioside GM2, implicated in Tay-Sachs disease, is especially common in the nervous tissue of the brain.

Infants with Tay-Sachs disease appear to develop normally for the first six months of life. Then, as nerve cells become distended with gangliosides, a relentless deterioration of mental and physical abilities occurs. The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. Death usually occurs before the age of 3.

Tay-Sachs is most common in Jews, although it is not an exclusively Jewish disorder.

Tay-Sachs in In the Presence of Mine Enemies[]

In 2010, Dr. Martin Dambach's diagnosis of Paul Klein's Tay-Sachs very nearly revealed the Kleins as Jews. The fact that Reichsführer-SS Lothar Prützmann had a great-nephew with Tay-Sachs saved the Kleins.

Paul Klein was euthanized before the disease fully developed.