Cystic Fibrosis Among White Americans

This table show the carrier frequency of cystic fibrosis in different ethnicities.

Cystic fibrosis is a common genetic disease within the white population in the United States.  It is an autosomal recessive disease that occurs in 1 in 2,500 Caucasian newborns, 1 in 17,000 African Americans, and 1 in 31,000 Asian Americans.  According to, Cystic fibrosis is caused by a mutation in the CFTR gene that disrupts the function of chloride channels and causes “cells lining the passageways in the lungs, pancreas, and other organs produce mucus that is unusually thick and sticky.”  The mucus clogs the airways and glands causing the symptoms.  The main symptoms are persistent coughing, frequent lung infections, wheezing or shortness of breath, and poor growth/weight gain in spite of a good appetite. In the end, it is usually end-stage lung disease that is the principal cause of death.

A possible reason that cystic fibrosis is common in white Americans could be similar to the situation where people who are carriers for the sickle cell anemia are resistant to malaria.  An article, Cystic fibrosis heterozygote resistance to cholera toxin in the cystic fibrosis mouse model suggests that “cystic fibrosis heterozygotes might possess a selective advantage of resistance to cholera”.  Since cholera was a problem in Western Europe in the 1800’s they could have passed on the resistance to their offspring leading to a larger number of the population being carriers for cystic fibrosis.

In lecture 2.2 it said there is no way to genetically test for race.  So I would say that there is no direct relationship between race and genetics.  There is obviously a relationship between genetics and health considering how mutations in genes can affect someone’s health, but genetics is not the only factor that determines health.  Also according to lecture 2.2 you have to self identify yourself as black to be prescribed BiDil.  The fact that you can self identify yourself as one race or another sounds like you could identify yourself as black one day and as white the next. If that is true, and then your health doesn’t change at the same moment you change your mind, then I would say there isn’t any real relationship between race and health.

1 thought on “Cystic Fibrosis Among White Americans

  1. Great post! If as you said race is not genetic, what alternative explanations might there be for variation in health problems between races? Great inclusion (in your chart) of Ashkenazi Jewish people – did you come across anything about why there is such disproportionate prevalence in this population?

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