as Risk Allele and as Protective Allele for Both Early- and Adult-Onset Multiple Sclerosis in a Hellenic Cohort.

: Human Leucocyte Antigens (HLA) represent the genetic loci most strongly linked to Multiple Sclerosis (MS). Apart from and , alleles have been previously studied regarding their role in MS pathogenesis, but to a much lesser extent. Our objective was to investigate the risk/resistance influence of alleles in Hellenic patients with early- and adult-onset MS (EOMS/AOMS), and possible associations with the risk allele. : One hundred MS-patients (28 EOMS, 72 AOMS) fulfilling the McDonald-2010 criteria were enrolled. HLA genotyping was performed with standard low-resolution Sequence-Specific Oligonucleotide techniques. Demographics, clinical and laboratory data were statistically processed using well-defined parametric and nonparametric methods and the SPSSv22.0 software. : No significant differences were found between EOMS and AOMS patients for 23 distinct and 12 alleles. The allele frequency was found to be significantly increased, and the allele frequency significantly decreased, in AOMS patients compared to controls. The allele was to be found significantly decreased in AOMS and EOMS patients compared to controls. : Our study supports the previously reported risk susceptibility role of the allele in AOMS among Caucasians. Additionally, we report for the first time a protective role of the allele among Hellenic patients with both EOMS and AOMS.