diagnosis and prognosis
- The two main indicators for diagnoses of Tay-Sachs are the absense or near-absense of Hexosaminidase A and a cherry-red spot. If suspected of having Tay-Sachs, people are given a blood test to test the levels of Hexosaminidase A, which may be followed by a back-up DNA test. People with noticeable eye problems will be taken to an opthalmologist, where a cherry-red spot can be found. As you can see in the picture below, a cherry-red spot occurs in the fovea, which is the area in the center of the retina.
"Cherry-red Spot" (Hackel, 2009)
- According to the University of Michigan Kellogg Eye Center, "The center of the fovea appears bright red because it is surrounded by a milky halo. This halo represents loss of retinal transparency which comes from a pile up of ganglioside in ganglion cells. The ganglioside accumulates because its catabolic enzyme (hexosaminidase A) is missing. Remember that there are no ganglion cells in the center of the fovea, so that the underlying choroid transmits its red color" (Trobe Md) (Basically the milky area represents the build-up of the fatty acid, which contrasts with the red of the unaffected fovea). These usually only appear in children though, and are not seen in adults. For many adults, the process of diagnosis is a long and difficult one. Most cases are dismissed as just symptoms of old age, and some people are even misdiagnosed with ALS and MS. Patients with mental health issues usually have the longest wait.
- The prognosis for the Infantile and Juvenile forms is that most children will die before the age of 4, even if provided with advanced medical care.