Cystic Fibrosis is not only the most common, but the most deadly inherited disease that affects Caucasian Americans. Cystic fibrosis is a disease in which a mutated gene causes a thick and sticky mucus to be produced, resulting in mucus build up in the lungs and digestive tract. This is turn causes life threatening lung infections and serious digestive problems.
There are approximately 30,000 Americans that have CF with about 1,000 new cases per year. The disease is most common in Caucasians of Northern European descent. It has been found that Cystic Fibrosis is much more common in White Americans than African Americans, Hispanics, and Asian Americans. Millions of Americans are carriers of this mutated Cystic Fibrosis gene, but an affected person must inherit two of these genes in order to display symptoms of the disease. Studies suggest that at least one in 29 White Americans carry the cystic fibrosis gene.
This specific gene mutation is thought to have arisen during the Stone Age in Europe and spread through hunters and gatherers across the continent and eventually to the US during migration. The gene is though to be 52,000 years old. Recent studies also show that even though Cystic Fibrosis is lethal when you inherit two of these mutated genes, there may be some evolutionary benefit to the carriers of this gene because if there were no selective advantage to the gene, it would have disappeared thousands of years ago. Because this mutated gene has persisted all these years is the reason why Cystic Fibrosis is so common today. It is not entirely clear to researchers what this specific advantage is, although they have come up with theories that the cystic fibrosis gene offered Cholera resistance and protection against diarrhea and dehydration. This is thought to be because CF disrupts salt and water balance in the body, which is the cause of the thick mucus build up.
I think that for genetic factors, this gene has become so prevalent because cholera and even diarrheal diseases were considered fatal to inhabitants of Western Europe when this mutated gene evolved, so there would have been a huge selective advantage to this gene. There are not so much social determinants to account for the occurrence of Cystic Fibrosis, but an early diagnosis scan improve survival. Antibiotics, inhalers, and other therapeutic medications can help quality of life for those wealthy enough to afford them.
Race, genetics, and health are three factors that are all intertwined in determining the occurrence of diseases among populations. Certain mutated genes are definitely more prevalent in specific races than other, which can lead to health or illness, depending if the mutation is positive or negative. Like the lecture stated, biologically discrete races do not exist. So even though there may be genes that are more common to certain cultural races, this does not mean only these races experience these diseases. For example, the lecture talked about Pima Indians and the occurrence of Type II diabetes. These altered genes that allowed for the quick processing of sugar and efficient fat storage got passed through genetic drift because these populations lived very near one another and rarely married outside their culture, which is why the mutation survived. However, this is not to say this mutation would not be passed to someone outside this culture through reproduction.