ZASP/LDB3-related atypical myopathy with subtle cardiac impairment unveiled by COVID-19 infection: a short report.

Case presentation. A 34-year-old male with congenital clubfoot, post-exertional rhabdomyolysis, and a family history of sudden cardiac death in mid-life was evaluated for a severe rhabdomyolysis. Although muscle biopsy revealed desmin-dystrophin-positive cytosolic protein aggregates, no other signs were noted aside from persistently elevated CK levels (10x normal). After a mild SARS-CoV-2 infection at age 55, a mild cardiomyopathy was observed via cardiac MRI, without specific patterns indicative of myocarditis. Subsequently, NGS analysis identified a heterozygous likely damaging variant in the LDB3 gene, thus broadening the phenotypic spectrum of LDB3-related myopathies to potentially include congenital clubfoot and recurrent exertional rhabdomyolysis. Additionally, a possible link was suggested between the viral infection and the exacerbation of the otherwise subtle, undetected cardiomyopathy. In the context of hyperCKemia and a positive family history for unexplained cardiac abnormalities, broad-spectrum NGS testing, and cardiac MRI in selected cases, should be considered for timely diagnosis and interventions.