Tay-Sachs
Tay-sachs disease is a rare, fatal disease. It is caused from a mutation on chromosome 15. This occurs due to the absence of an enzyme called called 'hexosaminidase A.' Without the enzyme, hex A, chemicals called gangliosides build up in the nerve cells especially in the brain. Due to this buildup, this causes the nervous system to function abnormally. Tay-sachs is an autosomal recessive disease which means that in order to have the disease, a person needs to inherit both recessive alleles. This also means that the parent of the affected child either has to be a carrier or actually have the disease.
Forms
Tay-Sachs appear in three different forms. The forms are based on the age in which the symptoms begin to appear. The forms are Classic Infantile, Juvenile, and Late Onset.
Classical Infantile
Classical Infantile is the most common form that is diagnosed. During Classical Infantile, the symptoms appear during infancy. The nerve destruction begins while the baby is still in the womb. At first when the baby is born, the infant would appear healthy. "However at three to six months of age, an affected baby will begin to lost developmental skills and experience progressive weakness, loss of motor skills, increases startle response and myoclonic jerks" (Center for Jewish Genetics, 2014).
Juvenile
The form Juvenile have symptoms appear during childhood. Usually the symptoms appear between the ages 2-5. The symptoms that occur in children include clumsiness, slurred speech, swallowing issues, muscle cramps, and the child would slowly lose developmental skills until they become unresponsive.
Late Onset
Late Onset has symptoms that usually appear during adolescence or in adulthood. This form of Tay-sachs is less severe because some of the enzyme functions. However it is still difficult to cope with. Adults who has this for of Tay-Sachs usually has mental heath symptoms such as psychotic and bipolar. They would also experience trouble swallowing and slurred speech. They would also gradually decline to having more assistance for mobility,
Characteristics/Symptoms
People who has Tay-Sachs has unique characteristics. Some of these characteristics are having a cherry red spot in the center of the macula. According to A.D.A.M., Inc. (2013), the symptoms include "deafness, decreased eye contact, blindness, decreased muscle tone (loss of muscle strength), delayed mental and social skills, dementia, increased startle reaction, irritability, listlessness, loss of motor skills, paralysis or loss of muscle function, seizures, and slow growth."
Who it affects?
Tay-Sachs disease is commonly found in Ashkenazi Jewish population. It can also be found in people who were a descendant of French-Canadian from Louisiana and also from the Cajun population. The statistics for Tay-sachs is the same for people who are descents from Ashkenazi Jewish, French-Canadian, and Cajun population. The disease could also appear in Irish Americans and also in the general population.