What describes the phenotype of an individual heterozygous for one ΔF508 and one wild-type CFTR allele?

The phenotype of an individual heterozygous for one ΔF508 and one wild-type CFTR allele is best described as more resistant to typhoid fever than wild-type homozygotes and does not have cystic fibrosis (CF).

The ΔF508 mutation in the CFTR gene is a common cause of cystic fibrosis, a genetic disorder that affects the respiratory and digestive systems due to the production of thick and sticky mucus. When an individual has one wild-type allele and one ΔF508 allele, they typically do not exhibit the full spectrum of symptoms associated with cystic fibrosis. This is because the presence of the wild-type allele allows for some normal CFTR protein function, which helps maintain the balance of salt and water on epithelial surfaces.

Furthermore, studies have suggested that individuals with the ΔF508 mutation may have some degree of resistance to certain infectious diseases, like typhoid fever, due to the altered immune response. This is especially true when comparing these heterozygous individuals to those who are homozygous for the ΔF508 mutation or those who possess the wild-type genotype. Hence, the presence of one functional wild-type CFTR allele allows for normal health concerning cystic fibrosis and offers an advantage in terms of disease resistance