What is CFTR variant?

CF is caused by the presence of variants in both copies of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene, each inherited from one parent. CFTR pathogenic variants affect CFTR protein at different levels: synthesis (mRNA and protein), maturation, traffi cking, and channel activity.

What is F508del mutation?

The most common CF mutation, F508del, is primarily considered to be a processing mutation. The F508del mutation removes a single amino acid from the CFTR protein. Without this building block, the CFTR protein cannot stay in the correct 3-D shape.

How do you know if you are a carrier of cystic fibrosis?

How do I know if I am a carrier of cystic fibrosis? Carrier testing is available through a simple blood test. There are over 1,000 mutations that have been found to cause CF. Carrier screening can be done for the most common of these, and will identify about 85 to 90 percent of carriers in the Caucasian population.

How many types of cystic fibrosis are there?

Are there different types of cystic fibrosis? There are over 2,000 identified mutations of the cystic fibrosis gene. Cystic fibrosis is a very complex condition that affects people in different ways. Some suffer more with their digestive system than the lungs.

What are the most common types of mutations that cause cystic fibrosis?

The deletion of the phenylalanine 508 (ΔF508-CFTR) is the most common mutation among cystic fibrosis (CF) patients. The mutant channels present a severe trafficking defect, and the few channels that reach the plasma membrane are functionally impaired.

What are the odds of being a CF carrier?

People who have only one copy of a CFTR gene mutation do not have CF. They are called “CF carriers.” Each time two CF carriers have a child, the chances are: 25 percent (1 in 4) the child will have CF.

Which is milder F508del or G551D mutation?

This study suggests that patients with the G551D mutation and a second severe mutation have a milder clinical phenotype than F508del homozygous patients, but the phenotype is not as mild as patients with the R117H mutation.

How does G551D mutation affect the CFTR protein?

G551D is a class 3 mutation. The CFTR protein reaches the cell surface but chloride transport through the channel is defective. The CFTR channel is normal but the amount of protein at the cell surface is decreased. The CFTR channel is not stable at the cell surface so the amount of protein at the cell surface is decreased.

Which is better cystic fibrosis G551D or R117H?

Higher FEV 1 and body mass index and less impaired glucose tolerance was demonstrated in the patients with G551D and R117H compared to F508del homozygotes. There was a reduced yearly rate of decline of FEV 1 ( P < 0.05), infection with Pseudomonas aeruginosa along with reduced burden of care.