Cystic fibrosis

Definition

Cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene, leading to the production of thick and sticky mucus that can obstruct the airways and cause severe respiratory and digestive problems. This condition is inherited in an autosomal recessive pattern, meaning both parents must carry a copy of the mutated gene for a child to be affected. Understanding cystic fibrosis helps to illustrate the principles of Mendelian genetics and inheritance, particularly in relation to gene mutations and their phenotypic expressions.

5 Must Know Facts For Your Next Test

1. Cystic fibrosis affects approximately 1 in 3,500 live births in the United States, making it one of the most common genetic disorders among Caucasians.
2. Individuals with cystic fibrosis often suffer from chronic lung infections due to mucus build-up in the lungs, which creates an environment conducive to bacterial growth.
3. Cystic fibrosis can also affect the digestive system by obstructing pancreatic ducts, leading to difficulty in nutrient absorption and poor growth.
4. Carrier screening is available for cystic fibrosis, allowing individuals to determine if they are carriers of the CFTR gene mutation, which can inform reproductive choices.
5. Treatment for cystic fibrosis includes medications to thin mucus, antibiotics for infections, and in some cases, lung transplants to improve respiratory function.

Review Questions

• How does cystic fibrosis illustrate the principles of Mendelian genetics, particularly regarding inheritance patterns?
  • Cystic fibrosis demonstrates Mendelian genetics through its autosomal recessive inheritance pattern. This means that both parents must carry at least one copy of the mutated CFTR gene for their child to have cystic fibrosis. If both parents are carriers, there is a 25% chance with each pregnancy that their child will inherit two copies of the mutated gene and express the disorder. This clear example showcases how specific genetic traits can be inherited and expressed based on parental genotypes.
• Discuss the implications of carrier screening for cystic fibrosis in terms of genetic counseling and family planning.
  • Carrier screening for cystic fibrosis allows individuals or couples to understand their risk of having a child affected by this genetic disorder. If both partners are found to be carriers of the CFTR mutation, genetic counseling can provide them with information about their reproductive options, including IVF with preimplantation genetic diagnosis or using donor gametes. This proactive approach empowers families to make informed decisions regarding family planning and manage potential health issues associated with cystic fibrosis.
• Evaluate the impact of cystic fibrosis on patient quality of life and the importance of ongoing research in this field.
  • Cystic fibrosis significantly impacts patient quality of life due to its chronic respiratory issues, nutritional challenges, and frequent medical treatments. As patients often require daily therapies and may face a reduced life expectancy, their physical, emotional, and social well-being can be affected. Ongoing research is vital as it leads to advancements in treatment options such as targeted therapies that address specific mutations within the CFTR gene. These innovations have the potential to improve outcomes and quality of life for those living with cystic fibrosis, highlighting the importance of continued investment in genetic research.

Related terms

CFTR gene: The gene responsible for producing the cystic fibrosis transmembrane conductance regulator protein, which helps control the movement of salt and water in and out of cells.

autosomal recessive inheritance: A type of genetic inheritance where two copies of a mutated gene must be present for the trait or disorder to manifest in an individual.

phenotype:

The observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences.