Expanded carrier screening for monogenic disorders: where are we now?

BACKGROUND: Expanded carrier screening (ECS), which can identify carriers of a large number of recessive disorders in the general population, has grown in popularity and is now widely accessible to prospective parents. This article presents a comprehensive overview of the characteristics of currently available ECS tests.

METHODS: To identify relevant ECS providers, we employed a multi-step approach, which included online searching, review of the recent literature, and consultations with researchers familiar with the current landscape of ECS.

RESULTS: As of January 2017, there were 16 providers of ECS tests: 13 commercial companies, 2 medical hospitals, and 1 academic diagnostic laboratory. We observed drastic differences in the characteristics of ECS tests, with the number of conditions ranging from 41 to 1792. Only three conditions (cystic fibrosis, maple syrup urine disease 1b, and Niemann-Pick disease) were screened for by all providers. Where the same disease gene was included by multiple providers, substantial differences existed in the mutations screened and/or variant interpretation/reporting strategies.

CONCLUSION: Given the importance of carrier screening results in reproductive decision-making, the observed heterogeneity across ECS panels is concerning. Efforts should be made to ensure that clear and concrete criteria are in place to guide the development of ECS panels. © 2017 John Wiley & Sons, Ltd.