The Heart of the Matter: DMD Carriers in The Duchenne Registry


Clinical Management

Poster Number: T321


Niki Armstrong, MS, CGC, Parent Project Muscular Dystrophy, Kayla Banks, MS, CGC, PPMD, Ann Martin, MS, CGC, Parent Project Muscular Dystrophy

Background: The Duchenne Registry (TDR) is a US-based international patient-report registry that collects data on individuals with Duchenne or Becker muscular dystrophy (DBMD) and female carriers. DBMD carriers have an increased risk for cardiomyopathy, with muscular symptoms ranging from asymptomatic to DBMD-like.
Methods: Carrier data collected through TDR from November 2007 through December 2023 was analyzed (N=650), including reported cardiac screening, cardiac medications (CM), and correlations with mobility aid (MA) use. Surveys are updated over time, and participants may choose which questions to answer. Consequently, participant numbers vary with each question.
Results: Cardiac screening is recommended for all DBMD carriers. In TDR, 73% (307/420) reported having an echocardiogram. The percent of carriers who had an echocardiogram increased with age, with at least 85% of carriers >50 having an echocardiogram. Carriers using MA were more likely to have an echocardiogram (89-90% versus 72%). 25% of participants (54/214) reported having a cardiac MRI, with 39% of those individuals reporting fibrosis. 12% (53/429) reported cardiac dysfunction.
Of carriers who provided CM data (N=372), 27% reported taking >1 CM. Beta-blockers were the most commonly reported CM, followed by ACE-inhibitors and diuretics. The mean and median ages of CM initiation were 37-40 years. Carriers who sometimes or always used a MA were more likely to report CM use than those who never use a MA. Carriers who self-reported as manifesting were more likely to use CM, 41% versus 16% in the asymptomatic carriers. CM use increased with age.
Discussion: While guidelines for carriers exist, there is very little real-world data on carrier experience. TDR provides valuable information on carriers’ reported CM use and cardiac imaging, demonstrating that carriers with neuromuscular involvement are more likely to have cardiac imaging and use CM. Because TDR is a self-selected population, there may be bias in which individuals choose to provide data.