Biology – Genetic technology applied to medicine | e-Consult

Genetic screening can significantly help this couple by determining the probability of their offspring inheriting cystic fibrosis. Carrier screening can be performed on both parents to identify if they are carriers of the recessive allele. This is typically done using DNA analysis.

There are two main types of screening available: carrier screening and pre-implantation genetic diagnosis (PGD).

Carrier screening provides the couple with information about their own genotypes. If both parents are carriers (heterozygous), there is a 25% chance with each pregnancy that their child will inherit two copies of the recessive allele and develop cystic fibrosis. There is a 50% chance the child will be a carrier like themselves, and a 25% chance the child will be unaffected and not a carrier.

PGD involves performing a biopsy on embryos created through in vitro fertilization (IVF) and testing them for the cystic fibrosis allele before implantation. If an embryo is found to be affected, it is not implanted. This guarantees that only unaffected embryos are implanted, preventing the birth of a child with cystic fibrosis. However, PGD is a more invasive and expensive procedure than carrier screening.

The implications of each screening method are different. Carrier screening provides information for family planning decisions, while PGD offers a way to avoid the birth of a child with cystic fibrosis. Both methods empower the couple to make informed choices about their reproductive future, considering the potential risks and benefits of each option.