Thursday, July 27, 2017

South Asian Social Castes

An article in the New York Times discusses how recessive genes are very common in regional groups; this is due to the founders effect.  These recessive genes are expressed when the child receives the mutated gene from both parents which is much more common in regional groups since they participate in consanguineous mating.  The Vysva population has a gene mutation which causes a bad reaction to muscle relaxants, Ashkenzai Jews are susceptible to Gaucher disease and cystic fibrosis, and congenital nephrotic syndrome is prevalent in the Finns population.  The mutations range from not harmful to terminal which creates a higher than average mortality rate.  Recording data about these diseases is important because it allows for prenatal and premarital screenings.  These screenings have been used within the Ashkenazi Jew population and has basically eliminated new cases of Tay-sachs disease in the population.  These populations provide opportunities to study how genes manifest naturally in humans.  It is important to research even the rarest diseases because these mutations can be inherited even if you do not marry your first cousin, some bloodlines simply have a higher risk for certain mutations.  


  1. It is good to find out that diseases resulting from consanguineous mating can be eventually eliminated or at least reduced. I would imagine it would be difficult to eliminate recessive genes that are found in multiple groups of people with little relation to each other, since the idea of consanguineous mating does not keep these groups from mating.

  2. I would assume that the close proximity these people are to each other contribute to the increase in recessive genes. It's a smaller gene pool therefore these genes will be expressed more. Though many of these genes are bad it is good that we have areas like this to study so we can better grasp the method of inheritance of these diseases.