title: Population-based differences in frequency of the transcobalamin II Pro259Arg polymorphism.
abstract: OBJECTIVE
  A common polymorphism of the transcobalamin II (TC-II) gene, Pro250Arg, has been implicated as a possible genetic factor in population-based differences in vitamin B(12) metabolism. Our objective was to determine whether the prevalence of TC-II Pro259Arg polymorphism differs significantly between Caucasian, Asian and African-American groups.
  
  
  METHODS
  Genomic DNA was available on 187 Caucasians and 43 Asians from the Toronto area, and 51 African-Americans from Northeastern United States. A mutagenically separated PCR method was employed to genotype these groups for the TC-II Pro259Arg polymorphism (776C-->G).
  
  
  RESULTS
  The frequency of the Arg 259 allele varied significantly among the three groups studied (0.439 in Caucasian, 0.558 in Asian and 0.363 in African; P = 0.022). The Asian group had a significantly higher frequency of the Arg 259 allele compared to the Caucasian (P = 0.030) and the African-American group (P = 0.006). The frequency of the Arg 259 allele in the Caucasian and African-American groups was not significantly different (P = 0.103).
  
  
  CONCLUSIONS
  Population-based differences in TC-II Pro259Arg frequency are significant and could be a contributor to ethnic variation in susceptibility to vitamin B(12) deficiency, a common and persistent problem.
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1L5.
authors.forename: Raffick A R
authors.initials: RA
authors.lastname: Bowen
authors.forename: Betty Y L
authors.initials: BY
authors.lastname: Wong
authors.forename: David E C
authors.initials: DE
authors.lastname: Cole
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D044466:Asian People; D044383:Black People; D002170:Canada; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D011110:Polymorphism, Genetic; D014155:Transcobalamins / Q000235:genetics*; D044465:White People; D001741:Black or African American
chemical_list: D014155:Transcobalamins