Potential Impact of Expanded Carrier Screening on the Incidence of Duchenne Muscular Dystrophy in Neonates

Background: Duchenne Muscular Dystrophy (DMD), the most common form of muscular dystrophy is associated with a 25 year life expectancy and occurs in 1 in 5,000 male births. At Brigham and Women’s Hospital over 18,000 infants have undergone newborn screening (NBS) for DMD without a positive result. We identified a case where a DMD carrier mother (detected through pre-pregnancy expanded carrier screening (ECS), underwent assisted reproductive technology that led to implantation of an embryo confirmed to be DMD negative. To test the hypothesis that ECS that included DMD might decrease the incidence of DMD through reproductive planning, we sought to determine the extent of ECS in our birth cohort. Methods: We performed a retrospective maternal chart review of DMD screened infants born in the first seven days of each month from January 2022 – May 2024. and documented ECS screening (with or without DMD), at pre-conception or post-conception [n= 2,614] Results: Of the screened participants 49.7% received ECS with DMD and 93.9% of the sample received some form of genetic screening. There was an increase in ECS with DMD from 2022 (46.6%) to 2024 (56.2%). Conclusion: Uptake of ECS may vary widely by geographic location, local practice norms and parental uptake but is prevalent in our cohort. Increasing ECS inclusive of DMD, along with intervention through ART, could explain why our DMD NBS has not identified an affected newborn.