Genotüübi

A genotype is the genetic constitution of an individual, represented by the specific alleles inherited at one or more loci. It refers to the particular genetic makeup that can influence heritable traits, though not all traits are determined solely by genotype, as environments can interact with genes.

Genotype is distinct from phenotype, the observable characteristics of an organism. A genotype is often described at specific gene loci with alleles such as A and a; organisms can be homozygous (AA or aa) or heterozygous (Aa). When describing a population, genotype frequencies for a given locus are considered, and models such as Hardy-Weinberg equilibrium are used to relate allele frequencies to genotype frequencies.

In medicine, agriculture, and research, genotype data are used to predict disease risk, drug response (pharmacogenomics), and to guide breeding programs. In studies, genome-wide genotyping helps identify associations between genetic variants and traits, contributing to our understanding of evolution, health, and biology.

Genotyping methods include DNA sequencing to determine base pairs, PCR-based assays for known variants, and SNP arrays that assay thousands to millions of variants. Newer approaches such as genotyping-by-sequencing and whole-genome sequencing provide broader or deeper views of genetic variation, depending on the research question, cost, and required resolution.

Genotype information complements phenotype and ancestry data and is central to genetics research, personalized medicine, and evolutionary biology. It also raises ethical considerations regarding privacy, consent, data sharing, and the potential for genetic discrimination.