The HLA locus and multiple sclerosis in Sicily.

Area of Science:

• Immunogenetics
• Neuroimmunology

Background:

• Multiple sclerosis (MS) is a complex autoimmune disease affecting the central nervous system.
• Genetic factors, particularly those within the human leukocyte antigen (HLA) complex, play a significant role in MS susceptibility.
• Understanding HLA allelic heterogeneity in diverse populations is crucial for unraveling disease mechanisms.

Purpose of the Study:

• To investigate the HLA-class II allelic heterogeneity in a Sicilian cohort of multiple sclerosis patients.
• To identify specific HLA alleles and haplotypes associated with MS susceptibility in this population.

Main Methods:

• Family-based association analysis was employed to assess the transmission of HLA alleles from parents to affected offspring.
• Analysis included specific HLA-DRB1 and HLA-DQB1 alleles and their combined haplotypes.

Main Results:

• Evidence of excess transmission was found for HLA-DRB1*1501, HLA-DRB1*04, and HLA-DQB1*0302 alleles in Sicilian MS patients.
• The DRB1*0400-DQB1*0302 haplotype showed excess transmission, suggesting a combined genetic effect.
• The HLA-DRB1*1501 allele, a known MS susceptibility factor, is shared with continental Italian MS patients.

Conclusions:

• The study identifies specific HLA-class II alleles and a haplotype associated with multiple sclerosis in the Sicilian population.
• Findings suggest that while some susceptibility alleles are shared across Italian MS cohorts, Sicilian patients also exhibit unique allelic patterns characteristic of Mediterranean populations.
• These results contribute to the understanding of the genetic architecture of MS in Mediterranean regions.