- A 31-year-old Caucasian female at 11 weeks gestation requires her primary-care provider for prenatal care cystic fibrosis (CF) carrier screening.
- The screening reveals that she carries the common delta F508 CF mutation.
- After genetic counselling, the patient’s partner is tested and is found to carry a different CF mutation.
- The carriership does not affect their individual health, but determines a risk for siblings.
- Any of the parents has 50% chance to transmit the mutation, and overall, the couple has 25% chance of having a child affected with cystic fibrosis.
- The couple is therefore offered genetic counselling and amniocentesis for prenatal diagnosis.