Many families are affected by disease every year. Most diseases appear more in one specific culture or race. An example of one of these diseases is Tay-Sachs. Tay-Sachs disease comes in three forms, infantile, juvenile (subacute), and late on-set. Infantile is the most common followed by late on-set.
Tay-Sachs disease in general is a rare genetic disorder that has no cure. In all forms of Tay-Sachs disease the enzyme hexosaminidase A (hex A) is lacking or at a low amount. Hex A is necessary to break down normal fatty compounds in the body cells. Therefore these compounds accumulate gradually and damage the brain and nerve cells causing the cells to function improperly. Tay-Sachs is an autosomal recessive disease. Therefore in order to have this disease a person has to inherit a gene from both parents. A person with Tay-Sachs disease would have a genotype of tt, meaning that they would have two recessive genes for this disease.
Infantile Tay-Sachs disease appears in approximately one in every 2,500 Ashkenazi Jewish newborns along with some newborns out of the French Canadians and Louisiana Cajun cultures. Infantile Tay-Sachs disease has many symptoms. Symptoms come along more as the infant gets older. In the first three to six months the symptoms start to become noticeable. During the first eight months one may be able to characterize this disease by the onset of severe mental and developmental retardation. Another early sign may be a cherry-red spot in the retina of the eye. Symptoms may also progress from a difficulty in focusing and a lack of eye contact to difficulty sitting up and rolling over. The infant may lose their vision and have uncontrollable seizures. Tay-Sachs disease often results in death by the age of five. The death my be a result of pneumonia or other infections.
Juvenile Tay-Sachs is much less common than the other two forms of this disease. Again Juvenile Tay-Sachs is most common in the Ashkenazi Jewish culture.