Tay sachs disease is a genetic disorder, which in most cases is fatal. It is most commonly found in infants whom die at a young age due to this disorder. The cause of this disorder is caused by one bad gene, which causes everything to go wrong. Other cells then develop prematurely and results in death of those particular cells. In this picture it described the probability that the baby of this couple will result with children with tay sachs. If both parents are heterozygous, then only 25% will not become affected by this disease. The survival rate for these children isnt very high as you can see.