Experiences of parents who receive a false-positive CK-MM screening for their newborn.

Duchenne muscular dystrophy (DMD) is a rare inherited, X-linked neuromuscular disorder that leads to a progressive decline in physical mobility, muscle atrophy, and premature death. Newborn screening (NBS) offers the potential for earlier diagnosis and earlier intervention, although NBS using the creatine kinase isoenzyme (CK-MM) assay may detect conditions other than DMD and lead to initial false-positive results. Early Check, a voluntary supplemental newborn screening study in North Carolina, screened 16,566 newborns for DMD over nearly 3 years. Parents and legal guardians of infants who received an initial false-positive screen result for DMD (n = 20) were interviewed about their experiences. Data were coded in NVivo using directed content analysis. Participants described feelings of stress, shock, and concern associated with receiving the initial positive screening result, and varying levels of stress and anxiety while waiting for confirmatory genomic panel testing during the follow-up period. The study genetic counselor played a critical role in sharing the initial false-positive results, answering parents'/guardians' questions, and informing them of factors other than DMD that can cause elevated CK-MM levels. Despite the stressful experience of receiving a false-positive result, parents/guardians found value in participating in Early Check, as it provided knowledge about their child's health and the opportunity for earlier intervention, if needed.