Tay-Sachs disease may give partial resistance to tuberculosis

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Tay-Sachs disease is a recessive genetic disorder that is more common in certain ethnic groups, including Ashkenazi Jews. It is caused by a deficiency in an enzyme called hexosaminidase A, leading to the accumulation of gangliosides in the brain and nervous system, causing severe neurological damage. However, it has been suggested that Tay-Sachs carriers (heterozygous individuals) may have some partial resistance to tuberculosis. This could be an example of a balanced polymorphism, where the same allele that causes a disease in its homozygous form also confers an advantage when present in its heterozygous form. However, this resistance is only partial, and having two copies of the Tay-Sachs mutation would still cause Tay-Sachs disease, with all its debilitating effects. There is no evidence to suggest that Tay-Sachs increases susceptibility to malaria, and it is not absent in Jews of Eastern European ancestry - in fact, it is more common in that population.

Tay-Sachs Disease May Give Partial Resistance to Tuberculosis