I respectfully disagree with my colleague’s assessment of cystic fibrosis. While they correctly stated that cystic fibrosis is an autosomal recessive disease that affects chromosome 7, their explanation of the physiological mechanisms involved in the disease is limited.
Cystic fibrosis is indeed caused by a mutation in the cystic fibrosis transmembrane regulator (CFTR) gene, which codes for the CFTR protein. The CFTR protein is responsible for regulating the flow of salt and fluids in and out of the cell. However, my colleague’s explanation of the role of chloride ions and mucus production is oversimplified.
The CFTR protein serves as a chloride channel, allowing for the movement of chloride ions in and out of cells. This channel is particularly important in cells that line the airways, sweat glands, and pancreas. In individuals with cystic fibrosis, the mutated CFTR protein is either absent or dysfunctional, leading to impaired chloride transport and abnormal mucus production.
The abnormal mucus in individuals with cystic fibrosis is not solely thick and sticky because of the lack of chloride. It is also accompanied by a decreased volume of water in the mucus, leading to a dehydrated and viscous consistency. This abnormal mucus obstructs the airways, making individuals with cystic fibrosis more susceptible to recurring lung infections and the development of cysts in the lungs.
In addition to the lungs, cystic fibrosis also affects other organs such as the pancreas and digestive system. The lack of functional CFTR protein in the pancreas leads to the obstruction of pancreatic ducts, preventing the secretion of digestive enzymes. This results in a decreased absorption of nutrients and malnutrition. The thick mucus can also affect the production and release of insulin, which can lead to the development of diabetes in some individuals with cystic fibrosis.
My colleague correctly mentioned that males with cystic fibrosis are infertile due to the mucus blocking the vas deferens, but they did not elaborate on the reproductive issues that females with cystic fibrosis may face. Women with cystic fibrosis may experience difficulties during pregnancy due to the impact of the disease on their overall health and lung function. Pregnancy can exacerbate respiratory symptoms in individuals with cystic fibrosis and requires careful management.
Furthermore, my colleague did not provide any discussion on the genetics and inheritance pattern of cystic fibrosis. Cystic fibrosis is inherited in an autosomal recessive manner, meaning that both parents must be carriers of the mutated CFTR gene for their child to have cystic fibrosis. The chances of two carriers having a child with cystic fibrosis are 25%, while their child has a 50% chance of being a carrier and a 25% chance of neither being a carrier nor having the disease.
The frequency rates mentioned by my colleague are accurate, with cystic fibrosis being more common in the Caucasian population compared to other ethnicities. However, it is important to note that genetic variation can exist within populations, and these rates can vary.
In conclusion, while my colleague provided a basic overview of cystic fibrosis, their explanation lacked a comprehensive understanding of the physiological mechanisms involved. It is crucial to consider the complex interplay of chloride ion transport, mucus production, and organ-specific effects in understanding the pathophysiology of cystic fibrosis.