Bio Agents

Title of Research: Heterozygote Advantage in Tay-Sachs

 

Hypothesis: The heterozygotes of the Tay-Sachs allele have greater advantages in certain characteristics compared to homozygous dominants, maintaining the recessive allele in the population despite its lethality in the homozygous recessive state.

 

Research proposal: Tay-Sachs is a devastating genetic disorder that is invariably lethal in children who are homozygous recessive for the deleterious allele. However, its prevalence among a specific ethnic group, the Ashkenazi Jews, poses a biological mystery. In other cases of harmful recessive genetic diseases, we learned that the heterozygous state may be advantageous, conferring higher fitness to those who possess one dominant and one recessive allele, thus explaining the prevalence of the deleterious allele in the population. We postulate that the high frequency of Tay-Sachs disease among the Ashkenazi is also caused by heterozygote advantage. As such, we are tasked with finding advantageous traits among individuals who are heterozygous for the Tay-Sachs allele that potentially confer higher fitness on these individuals. There are two methods for locating these individuals: 1) Look for the parents of children with Tay-Sachs disease, and 2) Look for individuals who tested positive for one Tay-Sachs allele in DNA tests such as those provided by 23andMe. After we locate these individuals heterozygous for the Tay-Sachs allele, we will seek their consent to participate in the study. The study entails the filling out of an anonymous questionnaire that contains questions designed to determine the possession of certain advantageous traits that are postulated to lead to higher fitness over the general population.

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Reference:

The Troubled Dream of Genetic Medicine, by Wailoo, 2006

Human Evolutionary Genetics, 2nd edition, by Jobling, 2013