title: Genetic factors and multiple sclerosis in the Moroccan population: a role for HLA class II.
abstract: OBJECTIVE
  Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system that mainly affects young adults. The association between susceptibility to MS and HLA class II genes, in particular the DRB1*15 allele, has been reported in diverse ethnic groups. The aim of our study was to investigate the distribution of HLA-DRB1* and -DQB1* alleles in Moroccan population and their implication in the susceptibility to the disease.
  
  
  METHODS
  Fifty-seven MS patients were compared to 172 healthy controls unrelated to one another and matched by age, sex and ethnic origin. HLA class II (DRB1* and DQB1*) typing was performed by PCR-SSP and/or Luminex (PCR-SSO). Allelic and haplotypic frequencies, P-values, odds ratio (OR) and 95% confidence interval (CI) were calculated using the software SPSS.
  
  
  RESULTS
  A significant increase of DRB1*15 allele frequency (17.6% vs 8.4%, OR=2.67, 95% CI=1.36-5.23, P=0.004) and HLA-DRB1*15-DQB1*06 haplotype (8.8% vs 4.08%, OR=2.78, 95% CI=1.41-5.48, P=0.002) were observed in Moroccan MS patients. No association of the DR15 allele with sex or age at onset was appreciated. Concerning HLA-DQB1* alleles, no significant difference between patients and controls was found.
  
  
  CONCLUSIONS
  Our results reveal a role for HLA-DRB1*15 allele molecules in the predisposition of Moroccan patients to MS. Although this study should be confirmed on a larger sample size, it analyzes for the first time the possible role of a genetic marker for susceptibility to MS in Moroccan population.
authors.affiliation: Unité d'immunologie, service de transfusion sanguine et d'hémovigilance, CHU Ibn-Sina, Rabat, Morocco; UPR d'immunologie, faculté de médecine et de pharmacie de Rabat, université Mohamed V, Souissi, Rabat, Morocco. Electronic address: ouadghirisanae@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Ouadghiri
authors.forename: K
authors.initials: K
authors.lastname: El Alaoui Toussi
authors.forename: C
authors.initials: C
authors.lastname: Brick
authors.forename: E H
authors.initials: EH
authors.lastname: Ait Benhaddou
authors.forename: N
authors.initials: N
authors.lastname: Benseffaj
authors.forename: A
authors.initials: A
authors.lastname: Benomar
authors.forename: M
authors.initials: M
authors.lastname: El Yahyaoui
authors.forename: M
authors.initials: M
authors.lastname: Essakalli
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D005802:Genes, MHC Class II / Q000502:physiology*; D020022:Genetic Predisposition to Disease; D059866:HLA-DQ beta-Chains / Q000235:genetics; D059811:HLA-DRB1 Chains / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009018:Morocco / Q000453:epidemiology; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000235:genetics*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains
keywords: DRB1*15; HLA class II; HLA de classe II; Luminex; Maroc; Moroccan population; Multiple sclerosis; Sclérose en plaque