Question:
Solution:
The gene that encodes the CFTR protein is located on chromosome 7.
The most common disease-causing mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is the out-of-frame deletion of 3 nucleotides (CTT). This mutation leads to the loss of phenylalanine-508 and a silent codon change for isoleucine-507.
Then, the correct answer is:
Three nucleotides in the CFTR gene are delated on chromosome 7.
