Lucy and Tom's Story

Genetic Testing Based on Ethnic Background

When Lucy and Tom were ready to start a family they talked to Lucy's doctor about their plans. Was there anything they could do to maximize the chance of a successful pregnancy and a healthy baby? The doctor asked questions about their personal and family histories and then raised the option of genetic testing to see if they were carriers for an inherited condition known as cystic fibrosis (CF). She explained that this condition was more common in people with European ancestry, like Lucy and Tom, and that it was still relevant for them despite the fact that neither of them had a family history of CF. Lucy and Tom had a lot of questions and the doctor suggested that they talk with a genetic counselor prior to making their decision about carrier testing.

During genetic counseling Lucy and Tom learned about the symptoms of CF, how it is inherited, and about the information that genetic carrier testing could give them. They understood that their chances of having a child with CF would be as high as 1 in 4 if they were both carriers, or much lower than that if neither, or only one of them was a carrier. They agreed that they were interested in understanding their chances of having a child with CF, even though they were not sure about whether they would want to manage a future pregnancy any differently based on the results.

Lucy pursued CF carrier testing first and her results showed that she had inherited the most common CF gene mutation. Tom pursued testing next and the couple was relieved to learn that the results were negative: Tom was not a CF carrier. This meant that their chances of having a child with CF was only about 1 in 800. Both felt that the counseling and testing process had been useful in allowing them to make the most informed choice possible before planning their pregnancy.