Genotype-Phenotype Correlation of the Childhood-Onset Bethlem Myopathy in the Mediterranean Region of Turkey

OBJECTIVES: Collagen-VI-related myopathies are caused by both dominant and recessive mutations in the three collagen-VI-related genes (COL6A1, COL6A2, and COL6A3) and present as two different major clinical entities; Bethlem myopathy and Ullrich congenital muscular dystrophy. METHODS: In this study, we evaluated the clinical, pathologic, and genetic features of 8 patients with Bethlem myopathy from 3 families. RESULTS: We inspected disease course differences with age and mutations. Different variants in COL6A1 and COL6A2 genes were detected. Muscle MRI of the lower limbs showed a specific pattern of muscle involvement with variable severity of fatty infiltration. One family had essential hypertension. CONCLUSION: Genotype-phenotype correlation studies are critical in determining gene or mutation-targeted therapies, patient follow-up, severity and progression prediction, and genetic counselling.