Myofibrillar myopathy with congenital cataract and skeletal anomalies without mutations in the desmin, αB-crystallin, myotilin, LMNA or SEPN1 genes

Myofibrillar myopathies are genetically heterogeneous. We present a sporadic case of an 8-year-old boy with unusual combination of congenital skeletal muscle myopathy, cataract and poly/syndactyly. Muscle pathology revealed a mild myopathic picture with hyaline plaques, showing dark green staining in modified trichrome reaction, and strong immunoreactivity for αB-crystallin, desmin and dystrophin. Analysis of the coding sequences of the desmin, αB-crystallin, SEPN1, lamin A/C genes and of exon 2 of the myotilin gene showed no abnormalities in the patient. Presented case expands the wide clinical spectrum of myofibrillar myopathies, reinforcing the need for further exploration of genetic causes for this group of disorders.