Time to diagnosis of Duchenne muscular dystrophy remains unchanged: Findings from the Muscular Dystrophy Surveillance, Tracking, and Research Network, 2000‐2015

Abstract

Introduction/Aims: With current and anticipated disease-modifying treatments, including gene therapy, an early diagnosis for Duchenne muscular dystrophy (DMD) is crucial to assure maximum benefit. In 2009, a study from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) showed an average diagnosis age of 5 years among males with DMD born from January 1, 1982 to December 31, 2000. Initiatives were implemented by the US Centers for Disease Control and Prevention (CDC) and patient organizations to reduce time to diagnosis. We conducted a follow-up study in a surveillance cohort born after January 1, 2000 to determine whether there has been an improvement in time to diagnosis. Methods: We assessed the age of diagnosis among males with DMD born from January 1, 2000 to December 31, 2015 using data collected by six US MD STARnet surveillance sites (Colorado, Iowa, western New York State, the Piedmont region of North Carolina, South Carolina, and Utah). The analytic cohort included 221 males with definite or probable DMD diagnosis without a documented family history. We computed frequency count and percentage for categorical variables, and mean, median, and standard deviation (SD) for continuous variables. Results: The mean [median] ages in years of diagnostic milestones were: first signs, 2.7 [2.0]; first creatine kinase (CK), 4.6 [4.6]; DNA/muscle biopsy testing, 4.9 [4.8]; and time from first signs to diagnostic confirmation, 2.2 [1.4]. Discussion: The time interval between first signs of DMD and diagnosis remains unchanged at 2.2 years. This results in lost opportunities for timely genetic counseling, implementation of standards of care, initiation of glucocorticoids, and participation in clinical trials.

Age at diagnosis for Duchenne muscular dystrophy: Why we must do better

“…The results presented by Thomas et al are particularly disappointing given the number of publications in the literature over the years that showed delayed diagnosis in DMD. 1 van Ruiten et al reported similar diagnostic delays in a large cohort of DMD patients seen in the UK. 9 Health-care professionals involved in routine developmental screening programs need to be aware of the presenting features of DMD and should initiate CK testing.…”

“…The results presented by Thomas et al are particularly disappointing given the number of publications in the literature over the years that showed delayed diagnosis in DMD 1 . van Ruiten et al reported similar diagnostic delays in a large cohort of DMD patients seen in the UK 9 .…”

“…Thomas et al 1 show that there is still a long way to go to improve the age at diagnosis for DMD. Given that there are published standards of care and that disease‐modifying treatments are now available that have the potential to significantly improve outcomes, it is crucial that relevant health‐care professionals are familiar with DMD and know how best to screen for the condition.…”

“…This issue of the Journal includes an article by Thomas et al on behalf of the Muscular Dystrophy Surveillance, Tracking and Research Network (MD STARnet) 1 . The authors retrospectively review the age at diagnosis for males born with Duchenne muscular dystrophy (DMD) between 2000 and 2015.…”

What Is in the Myopathy Literature?

“…Although more study is required to determine whether earlier intervention improves outcomes in children with DMD, it seems unfortunate that this diagnostic delay remains and opportunities for genetic counseling, management, and participation in clinical trials are thereby delayed. Although educating primary care specialists may be helpful in reducing the diagnostic delay, it would seem that newborn screening would optimize early diagnosis and, as the authors state, “help to mitigate racial disparities that currently exist.” 10…”