Approximately 50% of study participants will be female. According to the ethnic and racial categories used by NIH, all of the study population would be classified as "Hispanic or Latino" (Mestizo). None of these participants live within a tribal indigenous culture; all speak Spanish while some also speak the indigenous (Quechua) language of their birthplace in Peru. At least 75% of this population has some "Amerindian" heritage. Less than 1% of individuals are either Asian-Peruvian or Afro-Peruvian in descent.