HLA-DRB1 and myasthenia gravis: DRB1*13 allele was found to be negatively associated with MG in our patients, similar to two studies: one performed on a myasthenic population of Norwegian descent, which pointed DRB1*13:01 as a protective factor for both EOMG and LOMG [17], and another on patients of Serbian descent, which pointed DRB1*13:01 as a protective factor for MuSK+MG [23].