GNE-Myopathy in a Greek Romani Family with Unusual Calf Phenotype and Protein Aggregation Pathology

GNE-myopathy is increasingly diagnosed in different ethnicities worldwide. No clear genotype-phenotype correlation has been established to date.

We describe two affected members of the same family from Balkan population carrying an already known homozygous pathogenic mutation in the kinase domain of the UDP-N-acetylglucosamine 2 epimerase/N-acetylmannosamime kinase (GNE) gene. The patients presented with severe distal weakness of lower legs combined with rimmed vacuoles in muscle biopsy. However, in contrast to the typical pattern of muscle involvement, one of them showed severe involvement of posterior calf muscles with spared anterior compartment of the lower leg muscles.

These patients provide evidence for a larger variability and further extend the phenotypic spectrum of GNE-myopathy to include preferential calf involvement.