Preimplantation check

Question

A friend of mine is a carrier of the F1052V mutation and her husband is a carrier of the 621+3A>G mutation. Do they have to do a preimplantation check? They will proceed with an IVF due to azoospermia.

Answer

Dear friend,
Your friend is a carrier of the F1052V gene, which is a mild CF mutation, while her husband is a carrier of a typical CF mutation. Both parents are carriers of CF mutations, which means that there is a 25% possibility for the baby to suffer from CF (mild type), a 50% possibility for the baby to be a carrier of one of the above mutations (healthy) and a 25% possibility for the baby to carry none of the above mutations.
The parents, if they do not wish to have a baby with CF, must proceed with the preimplantation check.
However, mutation analysis only gives a rough direction as "mild" mutations are usually associated with pancreatic sufficiency and a less severe course of lung disease compared to "typical" CF mutations, which are usually associated with pancreatic insufficiency. But it has clearly to be stated, that the individual clinical course and especially the degree of lung involvement cannot be predicted according to the genotype, as many other genetic (modifier genes etc.) and environmental factors play a role and severity of disease differs substantially even between patients with the exact same mutations.
Yours friendly,
Dr. Stavros Doudounakis

30.07.2012