TABLE 1.
Tay-Sachs disease | Canavan disease | |
---|---|---|
Mode of Inheritance | Autosomal Recessive (Each offspring has a one in four chance of receiving the mutated gene from both parents, and thus being affected by the condition.)1 | Autosomal Recessive3 |
Cause | Hexosaminidase A deficiency, leading to buildup of Gm2 gangliosides in neuronal cells1 | Aspartoacylase deficiency leading to buildup of N-acetylaspartic acid, leading to demyelination and spongy degeneration of the brain16 |
Symptoms | Weakness, loss of motor skills, decreased attentiveness, increased startle response, death usually before age four1 | Macrocephaly (large head), lack of head control, hypotonia (lack of muscle tone), seizures, spasticity, failure to achieve independent sitting, ambulation, or speech, death usually before teenage years3 |
Treatment | Supportive | Supportive |
Carrier Rate (Ashkenazim)4 | 1:31 | 1:41 |
Natural Incidence (Based on a carrier rate of 1:30 and 1:4033) | 1:3000 | 1:6400 |