American Native Continental Ancestry Group: Individuals whose ancestral origins are in the continents of the Americas.European Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Europe.African Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Africa.Asian Continental Ancestry Group: Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.Oceanic Ancestry Group: Individuals whose ancestral origins are in the islands of the central and South Pacific, including Micronesia, Melanesia, Polynesia, and traditionally Australasia.EuropeEuropean Union: The collective designation of three organizations with common membership: the European Economic Community (Common Market), the European Coal and Steel Community, and the European Atomic Energy Community (Euratom). It was known as the European Community until 1994. It is primarily an economic union with the principal objectives of free movement of goods, capital, and labor. Professional services, social, medical and paramedical, are subsumed under labor. The constituent countries are Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden, and the United Kingdom. (The World Almanac and Book of Facts 1997, p842)Genealogy and HeraldryPolymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Genetics, Population: The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.Genome-Wide Association Study: An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.Genetic Variation: Genotypic differences observed among individuals in a population.Gene Pool: The total genetic information possessed by the reproductive members of a POPULATION of sexually reproducing organisms.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.African Americans: Persons living in the United States having origins in any of the black groups of Africa.Indians, South American: Individual members of South American ethnic groups with historic ancestral origins in Asia.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Genetic Loci: Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.Linkage Disequilibrium: Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.Ethnic Groups: A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Trinidad and Tobago: An independent state in the Lesser Antilles in the West Indies, north of Venezuela, comprising the islands of Trinidad and Tobago. Its capital is Port of Spain. Both islands were discovered by Columbus in 1498. The Spanish, English, Dutch, and French figure in their history over four centuries. Trinidad and Tobago united in 1898 and were made part of the British colony of Trinidad and Tobago in 1899. The colony became an independent state in 1962. Trinidad was so named by Columbus either because he arrived on Trinity Sunday or because three mountain peaks suggested the Holy Trinity. Tobago was given the name by Columbus from the Haitian tambaku, pipe, from the natives' habit of smoking tobacco leaves. (Webster's New Geographical Dictionary, 1988, p1228, 1216 & Room, Brewer's Dictionary of Names, 1992, p555, 547)Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.