Population-based surveillance and prevalence of Duchenne/Becker muscular dystrophies (DBMD) in the United States (U.S.)

Additional author list: S Puzhankara, G Zamba, Y Zhu, K James, J Andrews, C Cunniff, E Ciafaloni, K Conway, C Druschel, K Mathews, D Matthews, F Meaney, L Miller, S Pandya, S Au, S Scollon, M Adams, N Street, and the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet)

INTRODUCTION: DBMD have an estimated prevalence of 1/3500 male births. Worldwide, estimates of DBMD vary, likely due to differences in diagnostic criteria, ascertainment, and survival. To date, no U.S., population-based prevalence data for DBMD by race/ethnicity have been published, leaving potential health disparities in diagnosis and treatment of these disorders undetected.

METHODS: In 2002, the Centers for Disease Control and Prevention established the MD STARnetto conduct longitudinal, population-based surveillance of diagnosis and life course of DBMD in the U.S. Six sites conducted active case finding and record abstraction to identify males with DBMD born from January 1, 1982 through December 31, 2011. Using these data, we calculated prevalence of DBMD by race/ethnicity and birth quinquennium (1986-1990; 1991-1995; 1996-2000; 2001-2005). Prevalence was calculated as (number of affected males age 5-9 years / number of male residents age 5–9 years); the lower bound of this age range corresponded to the average age at diagnosis. As such, census data used to identify male residents per birth quinquennium were those available in a subsequent data release (e.g., 2010 estimates used for 2001-2005 births).

RESULTS: Overall, 667 males with DBMD resided in an MD STARnetsite during one or more quinquennia from 1991-2010, producing a prevalence of 1.8/10,000 males. For this time period, racial/ethnic-specific prevalence was higher for Hispanics than non-Hispanic Whites or non-Hispanic Blacks. A similar pattern for prevalence was found for each quinquennium examined.

CONCLUSIONS: We present the first U.S., population-based report of racial/ethnic-specific prevalence of DBMD. Prevalence estimates differed by race/ethnicity and persisted across quinquennia, suggesting potential, persistent cultural and socioeconomic influences in diagnosis of DBMD that require more detailed examination. Use of our longitudinal, population-based surveillance approach permits comprehensive ascertainment and follow-up of individuals with DBMD to examine racial/ethnic differences in prevalence, treatment, and outcomes for these individuals.