DBMD and Beyond: Follow-up for babies with elevated CK-MM levels identified by expanded newborn screening


Newborn Screening

Poster Number: 120


Beth Boyea, MS, CGC, Don Bailey, MEd, PhD, Anne Wheeler, PhD, Holly Peay, MS, PhD, CGC


1. RTI International, 2. RTI International, 3. RTI International, 4. RTI International

BACKGROUND. The addition of Duchenne and Becker muscular dystrophy to the Recommended Uniform Screening Panel (RUSP) demands evidence of both the feasibility and the net benefit of population screening and follow-up. Progress toward DBMD newborn screening (NBS) remains hampered by inexperience with the creatine kinase MM isoform (CK-MM) assay and low numbers of presymptomatic infants identified, characterized, and treated. To address this evidence gap, the Early Check research study will offer voluntary expanded NBS for elevated CK-MM for all babies having standard NBS in North Carolina. Early Check will assess feasibility of population screening and follow-up while identifying and evaluating presymptomatic infants eligible for early treatment. While the sensitivity and specificity of CK-MM is improved over that of whole CK, conditions other than DBMD also associated with perinatal skeletal muscle damage could be identified. APPROACH. This presentation describes the follow-up plan for infants with elevated CK-MM to provide diagnostic testing, information, resources, support, care and referral for treatment. Screen-positive cases reflex to interrogation of the DMD gene with sequencing of a custom neuromuscular gene panel analyzed only if DMD studies are negative. Parents of babies with genetic diagnoses receive genetic counseling and developmental assessment by 3-months of age and a neuromuscular clinic research evaluation at 6 months, during which transition to clinical care is planned. For those without a genetic diagnosis, total CK will be measured. Parents of all babies with positive screening results–regardless of diagnostic outcome–are offered follow-up genetic counseling at 3 and 6 months, ongoing access to education and support materials, and invitation to the registry. CONCLUSIONS. Early Check's novel screening and follow-up approach for babies with elevated CK-MM will benefit families while contributing much-needed data to support a RUSP nomination.