Expanded carrier screening in an infertile population: how often is clinical decision making affected?

PURPOSE: Options for preconception genetic screening have grown dramatically. Expanded carrier screening (ECS) now allows for determining carrier status for hundreds of genetic mutations by using a single sample, and some recommend ECS prior to in vitro fertilization. This study seeks to evaluate how often ECS alters clinical management when patients present for infertility care.

METHODS: All patients tested with ECS at a single infertility care center from 2011 to 2014 were evaluated. The overall rate of positive ECS results and the number of couples who were carriers of the same genetic disorder were evaluated.

RESULTS: A total of 6,643 individuals were tested, representing 3,738 couples; 1,666 (25.1%) of the individuals had a positive test result for at least one disorder. In 8 of the 3,738 couples, both members of the couple were positive for the same genetic disorder or had a test result that placed them at risk of having an affected child. Three of eight cases were cystic fibrosis. In this cohort, ECS affected clinical care eight times after 6,643 tests (0.12%, confidence interval: 0.05-0.24%) in 3,738 couples (0.21%, confidence interval: 0.09-0.42%).

CONCLUSIONS: ECS is becoming more widespread. In a large case series, ECS affected clinical decision making for patients presenting for infertility care in 0.21% of cases. This information must be weighed when utilizing these tests and may be a helpful part of patient counseling.Genet Med 18 11, 1097-1101.