title: Genomewide admixture study in Mexican Mestizos with multiple sclerosis.
abstract: BACKGROUND
  Multiple sclerosis (MS) is a complex immune-mediated disease. It has been suggested that genetic factors could explain differences in the prevalence among ethnic groups. To know whether genetic ancestry is a potential risk factor for MS in Mexican patients and to identify candidate genes for the susceptibility to the disease we conducted an initial trial of genome-wide analysis.
  
  
  METHODS
  29 patients with diagnosis of definitive MS and 132 unrelated healthy controls were genotyped using the Affymetrix human 6.0 array. After QC procedures, ancestry determination and a preliminary case-control association study were performed.
  
  
  RESULTS
  We identified significant differences in the European ancestry proportion between MS cases and controls (33.1 vs. 25.56, respectively; p=0.0045). Imputation analysis in the MHC region on chromosome 6 showed a signal with a significant level (p<0.00005) on the HLA-DRB region. Additionally, a preliminary association analysis highlighted the ASF1B as novel candidate gene participating in MS.
  
  
  CONCLUSIONS
  Our data suggest that European ancestry is a risk factor to develop MS in Mexican Mestizo population. Conversely, indigenous ancestry of Asian origin seems to confer protection. Further studies with more MS cases are needed to confirm these findings.
authors.affiliation: National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur #3877, Mexico City 14269, Mexico.
authors.forename: Graciela
authors.initials: G
authors.lastname: Ordoñez
authors.affiliation: National Institute of Genomic Medicine of Mexico, Periférico Sur 4809, Mexico City 14610, Mexico.
authors.forename: Sandra
authors.initials: S
authors.lastname: Romero
authors.affiliation: National Institute of Genomic Medicine of Mexico, Periférico Sur 4809, Mexico City 14610, Mexico.
authors.forename: Lorena
authors.initials: L
authors.lastname: Orozco
authors.affiliation: National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur #3877, Mexico City 14269, Mexico.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Pineda
authors.affiliation: National Institute of Genomic Medicine of Mexico, Periférico Sur 4809, Mexico City 14610, Mexico.
authors.forename: Silvia
authors.initials: S
authors.lastname: Jiménez-Morales
authors.affiliation: National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur #3877, Mexico City 14269, Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Nieto
authors.affiliation: National Institute of Genomic Medicine of Mexico, Periférico Sur 4809, Mexico City 14610, Mexico.
authors.forename: Humberto
authors.initials: H
authors.lastname: García-Ortiz
authors.affiliation: National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur #3877, Mexico City 14269, Mexico. Electronic address: jsotelo@unam.mx.
authors.forename: Julio
authors.initials: J
authors.lastname: Sotelo
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People; D005260:Female; D005787:Gene Frequency / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D044465:White People / Q000235:genetics; D055815:Young Adult
keywords: Ancestry analysis; Association study; Autoimmunity genes; Mexican population; Multiple sclerosis in mestizos