title: European ancestry predominates in neuromyelitis optica and multiple sclerosis patients from Brazil.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) is considered relatively more common in non-Whites, whereas multiple sclerosis (MS) presents a high prevalence rate, particularly in Whites from Western countries populations. However, no study has used ancestry informative markers (AIMs) to estimate the genetic ancestry contribution to NMO patients.
  
  
  METHODS
  Twelve AIMs were selected based on the large allele frequency differences among European, African, and Amerindian populations, in order to investigate the genetic contribution of each ancestral group in 236 patients with MS and NMO, diagnosed using the McDonald and Wingerchuck criteria, respectively. All 128 MS patients were recruited at the Faculty of Medicine of Ribeirão Preto (MS-RP), Southeastern Brazil, as well as 108 healthy bone marrow donors considered as healthy controls. A total of 108 NMO patients were recruited from five Neurology centers from different Brazilian regions, including Ribeirão Preto (NMO-RP).
  
  
  RESULTS
  European ancestry contribution was higher in MS-RP than in NMO-RP (78.5% vs. 68.7%) patients. In contrast, African ancestry estimates were higher in NMO-RP than in MS-RP (20.5% vs. 12.5%) patients. Moreover, principal component analyses showed that groups of NMO patients from different Brazilian regions were clustered close to the European ancestral population.
  
  
  CONCLUSIONS
  Our findings demonstrate that European genetic contribution predominates in NMO and MS patients from Brazil.
authors.affiliation: Departamento de Neurociências e Ciências do Comportamento da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Doralina Guimarães
authors.initials: DG
authors.lastname: Brum
authors.forename: Marcelo Rizzatti
authors.initials: MR
authors.lastname: Luizon
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Santos
authors.forename: Marco Aurélio
authors.initials: MA
authors.lastname: Lana-Peixoto
authors.forename: Cristiane Franklin
authors.initials: CF
authors.lastname: Rocha
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Brito
authors.forename: Enedina Maria Lobato
authors.initials: EM
authors.lastname: de Oliveira
authors.forename: Denis Bernardi
authors.initials: DB
authors.lastname: Bichuetti
authors.forename: Alberto Alan
authors.initials: AA
authors.lastname: Gabbai
authors.forename: Denise Sisterolli
authors.initials: DS
authors.lastname: Diniz
authors.forename: Damacio Ramon
authors.initials: DR
authors.lastname: Kaimen-Maciel
authors.forename: Elizabeth Regina
authors.initials: ER
authors.lastname: Comini-Frota
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Vieira Wiezel
authors.forename: Yara Costa Netto
authors.initials: YC
authors.lastname: Muniz
authors.forename: Roberta Martins
authors.initials: RM
authors.lastname: da Silva Costa
authors.forename: Celso Teixeira
authors.initials: CT
authors.lastname: Mendes-Junior
authors.forename: Eduardo Antônio
authors.initials: EA
authors.lastname: Donadi
authors.forename: Amilton Antunes
authors.initials: AA
authors.lastname: Barreira
authors.forename: Aguinaldo Luiz
authors.initials: AL
authors.lastname: Simões
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics; D009471:Neuromyelitis Optica / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics; D055815:Young Adult
chemical_list: D005819:Genetic Markers