Question

Cystic fibrosis is a genetic disease in humans caused by a recessive mutation in the CFTR gene, which encodes a protein that regulates the transport of ions across the membrane of cells in the lungs. Based on your understanding of mutations and alleles, how would you describe this mutant allele of CFTR?

A) it is likely a haplosufficient allele
B) it is likely a haploinsufficient allele
C) it is likely a dominant allele
D) it is likely a gain of function allele
E) it is likely a loss of function allele

Answer 1

The mutant allele of the CFTR gene in cystic fibrosis is best characterized as a loss of function allele because it results in a defective protein that cannot regulate ion transport effectively.

Step-by-step explanation:

The mutant allele of the CFTR gene responsible for cystic fibrosis would most accurately be described as E) it is likely a loss of function allele. This allele leads to the production of a defective CFTR protein that cannot regulate ion transport effectively, resulting in the characteristic thick and sticky mucus found in individuals with cystic fibrosis. As the CFTR gene mutation is autosomal recessive, two copies of the mutant gene must be inherited for an individual to exhibit the disease, while carriers with only one copy of the mutation typically do not show symptoms.