Inherited myopathies in patients from Sub-Saharan Africa: Results from a retrospective cohort

The clinical epidemiology of inherited myopathies in sub-Saharan Africa (SSA) is unknown but likely underdiagnosed due to problems of scientific research and social issues. We report a case series of patients born in SSA, evacuated to Portugal through an international health protocol and seen at a single neuromuscular disorders centre, between January/2004 and August/2021. We identified 9 patients (5 males), 35.6 ± 19.3 years-old (10-64), from Cape Verde (n = 4), Angola (n = 2), Sao Tome and Principe (n = 2) and Guinea-Bissau (n = 1), with a delay in diagnosis of 19.7 ± 14.3 years. Seven patients (77.8 %) had positive family history. Most patients had significant morbidity, requiring wheelchair (55.6 %), and nocturnal non-invasive ventilation (55.6 %). The diagnosis included Bethlem myopathy (n = 2), Duchenne muscular dystrophy (n = 2), Emery-Dreifuss muscular dystrophy (n = 1), LGMDR1 (n = 2), LGMDR2 (n = 1), and type-1 myotonic dystrophy (n = 1). Genetic testing was remarkable for 3 mutations previously not described. Despite the small sample, the spectrum of hereditary myopathies in our cohort is like western studies. Further studies are needed to better understand the epidemiology of muscle diseases in SSA.