Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD). Cardiac magnetic resonance imaging (CMR) has become an emerging tool for cardiac disease stratification. We recently showed that 50% of maternal carriers have myocardial fibrosis demonstrated by late gadolinium enhancement (LGE); however, beyond a case report in 2010 of a mother and son dyad (MSD) suggesting a potential genetic influence on the presence and pattern of myocardial disease, there is a paucity of data of cardiomyopathy in MSDs. We sought to compare LGE presence and association with left ventricular ejection fraction (LVEF) in the development of cardiomyopathy within DMD MSDs.
Retrospective study of CMR studies in DMD MSDs from 2016 to 2021. Presence (+) or absence (-) of LGE and LVEF were determined. MSDs were divided into 4 groups represented as LGE (mother/son): A -/-, B +/-, C -/+, and D +/+.
A total of 18 MSDs with 36 CMR studies were compared. LGE was identified in 12 (67%) mothers and 9 (50%) sons. Group A had 4/18 (22%) MSDs that consisted of LGE- mothers and sons with normal LVEF respectively (LVEF 58.6±1.7% and 63.4±2.1%; ages of 49±6 and 16±2 years). Group B had 5/18 (28%) MSD that consisted of LGE+ mothers and LGE- sons with normal LVEF (LVEF 57.9±5.1% and 56±4.9%; age 48±10 and 14±3 years respectively). Group C had 2/18 (11%) MSDs that consisted of LGE+ sons and LGE- moms with normal LVEF (LVEF 57.7±5.2% and 56.9±1.1%, age 41±12 and 15±5 years). Group D had 7/18 (39%) LGE+ MSDs with abnormal LVEF seen in the sons but preserved LVEF in the mothers (LVEF 56.5±3.2% and 52.6±7.5%; age 53±7 and 17±5 years respectively). LGE concordance was observed in 11/18 (61%) MSDs (Groups A and D) with discordance seen in 7/18 MSDs (Groups B and C). LVEF was abnormal in the LGE+ sons in group D but preserved in LGE+ mothers regardless of son LGE status.
The high concordance of LGE within DMD MSDs suggests a potential genetic link in the development of myocardial fibrosis. Larger longitudinal studies with genotyping are needed to determine the development of cardiomyopathy in both maternal carriers of DMD and their sons as well as offer treatment insights.