case_images: PMC10538561_01
case_images: ECG. (A,B) Deep and narrow Q waves in leads I, aVL, and V5 to V6 (red arrows). Echocardiography. (C) Abundant prominent trabeculations and deep intertrabecular recesses were observed in the left ventricular walls. (D) Color flow imaging showed blood flow in intertrabecular recesses. CMR. (E,F) The non-enhanced CMR imaging (E, coronal position, F, short axis) disclosed significant cardiac enlargement, and distinct trabeculations localized to the inferior wall, lateral wall, and part of the anterior wall, as well as the apex.
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case_images: F1
case_images: Admission electrocardiography (ECG) showed sinus rhythm with a heart rate of 95 beats/min, deep and narrow Q waves in leads I, aVL, and V5 to V6 (Figures 1A,B). The two-dimensional transthoracic echocardiography (TTE) examination revealed prominent trabeculations and deep intertrabecular recesses of the left ventricular (LV) walls and apical areas (Figure 1C). Notably, color flow imaging showed blood flow in intertrabecular recesses (Figure 1D). The heart was significantly enlarged on CMR imaging, and distinct trabeculations were localized on the lateral wall, inferior wall, and part of the anterior wall, as well as at the apex (Figures 1E,F).
case_images: Clinical features in the siblings. Photographs of the proband (A,B) and his brother (C) showed the clinical features of proximal limb muscle atrophy and calf muscle pseudohypertrophy.
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case_images: F2
case_images: Significantly, the proband showed typical clinical features with progressive proximal limb muscle atrophy and calf muscles pseudohypertrophy (Figures 2A,B). Unexpectedly, as the primary caregiver during hospitalization, his younger brother showed proximal limb muscle atrophy and calf muscles pseudohypertrophy similar to the proband (Figure 2C).
case_images: Light microscopy and electron microscopy. (A,B) Light microscopy showed variation in muscle fiber size, accompanied by muscle fiber atrophy, hypertrophy of muscle fibers, partial degeneration of muscle fibers, with interstitial fibrosis, and adipose tissue infiltration. (C,D) Electron microscopy examination showed swollen mitochondria, expanded sarcoplasmic reticulum, focally dissolved myofilaments, and a few atrophied muscle fibers.
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case_images: F3
case_images: LM study with hematoxylin-eosin (HE) staining and immunohistochemical (IHC) staining demonstrated variation in muscle fiber size accompanied by atrophy of muscle fibers, hypertrophy of muscle fibers, partial degeneration of muscle fibers with interstitial fibrosis, and adipose tissue infiltration (Figures 3A,B). EM examination showed swollen mitochondria, expanded sarcoplasmic reticulum, focally dissolved myofilaments, and a few atrophied muscle fibers, without abnormal deposits (Figures 3C,D).
case_images: NGS and qPCR results of the siblings. (A) The proband (left, WHR0516) and a normal male (right, WHR0493). NGS determined the average sequencing depth and coverage of the target area in DMD gene, revealing deletion of exons 10-12 deletion (EX10_12 del) in the DMD gene of the proband. (B) WHR0534 and WHR0535 are two normal controls, while WHR0522 represented the proband's brother. The coding sequence of the DMD gene from the proband's brother was verified by qPCR, confirming the deletion of the same exons as the proband.
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case_images: F4
case_images: Results indicated a deletion of exons 10-12 (EX10_12 del) in the DMD gene (reference sequence NM_004006.2) (Figure 4A), affecting the normal expression of dystrophin. Moreover, we confirmed the deletion of the same exons in the DMD gene in his younger brother by qPCR (Figure 4B).