title: Natural fertility in northeastern Mexico: genetic structure by year of birth and birthplace.
abstract: BACKGROUND
  The aims of this population genetics study were 1) to ascertain whether 417 Mexican women with natural fertility (45 years of age, married, not using any family planning methods, residing in the state of Nuevo León) were genetically homogeneous, and 2) to compare the genetic structure of this selected population with the previously reported data of random populations of northeastern Mexico.
  
  
  METHODS
  A sample of 417 women was interviewed and selected in seven medical units of the Mexican Social Security Institute. They were grouped by their year of birth (1896-1925 and 1926-1955) and birthplace [persons whose four grandparents were born in the northeastern states (NE) and outside the northeastern states (Not-NE) of Mexico]. Eight genetic marker systems were analyzed.
  
  
  RESULTS
  Gene diversity analysis suggests that more than 99.1% of the total gene diversity can be attributed to variation between individuals within the population. Genetic admixture analysis suggests that this selected population, stratified by year of birth and birthplace, have received a predominantly Spanish contribution followed by a lesser Mexican Indian contribution.
  
  
  CONCLUSIONS
  The genetic structure of this selected population was homogeneous and similar to the random populations of northeastern Mexico. This finding corroborates the utility of this selected population for genetic and epidemiological studies.
authors.affiliation: Departamento de Genética de Poblaciones, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, Mexico. ricardocerda@hotmail.com
authors.forename: R M
authors.initials: RM
authors.lastname: Cerda-Flores
authors.forename: M I
authors.initials: MI
authors.lastname: Dávila-Rodríguez
mesh_terms: D000483:Alleles; D005260:Female; D005298:Fertility / Q000235:genetics*; D005787:Gene Frequency; D014644:Genetic Variation; D006801:Humans; D008800:Mexico; D008875:Middle Aged; D012111:Residence Characteristics