Abstract
Professional practice guidelines for cystic fibrosis (CF) carrier screening recommend the use of a 23 mutation panel that identifies couples at risk of having a child with classic CF while minimizing ambiguous test results. This study evaluated specific genetic counseling challenges that can arise from the use of expanded mutation panels and sequencing for CF carrier screening, and the strategies genetic counselors use to manage these challenges. We surveyed 129 genetic counselors to evaluate current practices. Of those surveyed, six counselors also participated in semi-structured telephone interviews during which they described a challenging case involving CF. The majority of counselors surveyed offer an expanded panel for routine CF carrier testing and order sequencing for at least one clinical \r indication. Study participants identified cost-effectiveness, high detection rate, and utility in specific clinical situations as benefits of these tests. However, counselors also felt that expanded panels and sequencing increase the genetic counseling challenges associated with CF carrier testing. Factors described as contributing to counseling challenges included the practices of referring providers, availability of many testing options, complex case management, and ambiguity related to the identification of mild mutations, complex alleles and variants of uncertain significance. Management strategies that counselors found helpful for complicated CF carrier cases included consultation with colleagues, review of the literature, use of professional and laboratory resources, and having specific approaches to counseling. Overall, genetic counselors acknowledge a role for expanded panels and sequencing in CF carrier screening, but would like to see more education for non-genetics professionals, guidelines to create more consistency in test offerings, professional resources for continuing genetic counselor education, and additional research on genotype-phenotype correlation. Especially with regard to genotype-phenotype correlation, future work should focus on clinically useful and realistic goals, including further educating genetic counselors about the ambiguity inherent in CF counseling.