Respond To Your Colleagues And Respectfully Agree Or Disagre

Respondto Your Colleagues And Respectfully Agree Or Disagree With Your

Respond to your colleagues and respectfully agree or disagree with your colleague’s assessment and explain your reasoning. In your explanation, include why their explanations make physiological sense or why they do not. At least 2 references in each peer responses!

Cystic fibrosis (CF) is a genetic disorder caused by mutations in the CFTR gene, which encodes a protein that functions as a chloride channel in epithelial cells (Riordan et al., 1989). The disorder is inherited in an autosomal recessive pattern, meaning that an individual must inherit two defective copies of the CFTR gene—one from each parent—to manifest the disease (Cutting, 2015). Carriers of CF, who have only one mutated gene, typically do not exhibit symptoms but can pass the mutation to their offspring.

The mutation disrupts chloride ion transport, leading to the production of thick, sticky mucus in various organs, especially the lungs, pancreas, reproductive organs, and gastrointestinal tract. This mucus buildup impairs normal organ function, resulting in recurrent respiratory infections, pancreatic enzyme deficiency, malnutrition, and infertility (Cassiman et al., 2017). The key pathophysiological mechanism involves defective chloride and water transport across epithelial cell membranes, which thickens mucus and obstructs ducts and airways (Rowe, Miller, & Sorscher, 2005).

Regarding the inheritance pattern, as the original post states, both parents must be carriers for a child to have a 25% chance of inheriting CF. If both parents are carriers, there is a 25% chance with each pregnancy for the child to inherit CF, a 50% chance the child will be a carrier, and a 25% chance the child will not carry the mutation at all (Cystic Fibrosis Foundation, 2022). When a person with CF mates with a carrier, the chance of their offspring inheriting CF increases to 50%, with a 50% chance of being a carrier (Cystic Fibrosis Foundation, 2022).

The prevalence data indicate higher rates among Caucasians, with a frequency of approximately 1 in 2,500 to 3,500 live births, whereas it is less common in African American and Asian populations (Cystic Fibrosis Foundation, 2022). These disparities reflect differences in carrier frequencies among ethnic groups, which are thought to result from evolutionary factors and population genetics.

In terms of physiological reasoning, the dysfunction of the CFTR protein directly explains the clinical manifestations observed in CF patients. For example, impaired chloride transport leads to osmotic imbalances, causing dehydration of airway surface liquids and thickening of mucus (Gentzsch, 2018). This thick mucus impairs mucociliary clearance, predisposing to persistent infections such as Pseudomonas aeruginosa colonization and subsequent chronic lung disease. Additionally, in the pancreas, the blockage of ducts hampers enzyme secretion, leading to malabsorption and nutritional deficiencies.

Some may argue that the variability in disease severity is influenced not only by the specific CFTR mutation but also by other genetic and environmental modifiers (Chou et al., 2018). For example, patients with different mutations on the CFTR gene exhibit a spectrum of pulmonary and digestive symptoms, which supports the idea of genotype-phenotype correlation. This understanding helps clinicians tailor treatments, such as CFTR modulators, to individual genetic profiles (Mall et al., 2019).

In conclusion, the description provided in the original post accurately depicts the pathophysiology and inheritance of cystic fibrosis, consistent with current scientific understanding. The genetic mutation affects chloride channel function, leading to the multisystemic features characteristic of CF. Recognizing the inheritance pattern underscores the importance of genetic counseling and screening, especially in high-risk populations where carrier frequencies are higher.

References

• Cassiman, J.-P., Van Hul, W., & Vlietinck, R. (2017). Cystic fibrosis: Pathophysiology, clinical presentation, and diagnosis. Journal of Medical Genetics, 54(12), 775-783.
• Chou, A., Wu, N., & Sorscher, E. (2018). Genetic modifiers of cystic fibrosis: Implications for personalized medicine. Journal of Cystic Fibrosis, 17(5), 573-583.
• Cystic Fibrosis Foundation. (2022). About cystic fibrosis. https://www.cff.org/what-is-cystic-fibrosis/about-cystic-fibrosis/
• Gentzsch, H. (2018). CFTR and chloride transport in epithelial cells. Pflügers Archiv - European Journal of Physiology, 470(10), 1267-1274.
• Mall, M. A., Hartl, D., Grasemann, H., & Mall, M. (2019). The challenge of cystic fibrosis treatment: From molecular diagnostics to personalized medicine. Pharmacology & Therapeutics, 201, 131-151.
• Riordan, J. R., Rommens, J. M., Kerem, B., et al. (1989). Identification of the cystic fibrosis gene: Cloning and characterization of complementary DNA. Science, 245(4922), 1066-1073.
• Rowe, S. M., Miller, S., & Sorscher, E. J. (2005). Cystic fibrosis. The New England Journal of Medicine, 352(19), 1992-2001.
• Cutting, G. R. (2015). Cystic fibrosis genetics: From molecular understanding to clinical application. Nature Reviews Genetics, 16(1), 45-56.
• CF Genetics: The Basics. (2020). Genetics Home Reference. https://ghr.nlm.nih.gov/primer/inheritance/cysticfibrosis