Tay-Sachs disease is a genetic disorder caused by the absence of the vital protein Hexosaminidase A isoenzyme. Hex-A breaks down fatty substances called GM2 gangliosides. However, infants with Tay-Sachs possess a gene mutation that makes them unable to produce Hex-A. As a result, fatty substances, or lipids, quickly accumulate inside neurons causing severe nerve damage. The rapid deterioration of the nervous system poses a challenge to researchers, however the answer could lie with an animal that has been around since biblical times- the Jacob sheep.