p.Ala120Thr mutation

Question

During the 9th week of my pregnancy I was checked for 89% of the CF mutations in the CFTR gene. The results were positive for the mutation p.Ala120Thr (c.358G>A, rs201958172). After the recommendation of my gynecologist my husband was checked for the same percentage of CF mutations in the CFTR gene. My doctor insisted that there is a 25% chance for the fetus to have CF only if my husband was a carrier of the same mutation as mine. After reading the answers here I realize that any two mutations can cause CF in the fetus. The results of my husband are not ready yet. I would like to ask if my husband tests negative for 89% of the CF mutations, what are the chances to have a baby with CF? If he is a carrier of a CF mutation do we need to have an amniocentesis? Thank you!

Answer

Dear friend,
You are a carrier of the p.Ala120Thr CF mutation. If your husband is a carrier of a CF mutation, then there is a 1:4 (25%) chance for the baby to have CF. If he is positive, then you need to discuss with your doctor the possibility of an amniocentesis. If your husband is negative for the 89% of the mutations, then the chance to have a baby with CF is reduced from 1:4 (25%) to 1:964.
Yours friendly,
Dr. Stavros Doudounakis

14.12.2015