There are a number of distinct strategies for dealing with genetic disease. Foetuses may be genetically screened and abortion of affected foetuses offered. This approach causes problems as abortion is unacceptable to many persons. An altemative fertilize eggs in vitro, screen them for genetic abnormalities and then slant only fertilized eggs which are genetically normal. A fourth possibility is the emerging technology of gene therapy, which will be discussed later.
Cystic fibrosis is a devastating genetic disease common in people of north- European descent.
This disease is due to the defect in a gene called rR. This gene is not located on the X chromosome, but is on an autosome. The mutant gene is recessive and so to be affected, a child must receive a copy of the mutant gene from both parents. Five percent of people of them European descent are carriers of the mutant gene. If a man ws that he has one mutant gene, he has to consider if it is wise to be with a woman who is a carrier, and vice versa. Nowadays it is easy to check if a person has a mutant CFTR gene.