Unifactorial

Unifactorial is a term used in genetics and evolutionary biology to describe a trait or characteristic that is determined by a single gene. This is in contrast to multifactorial traits, which are influenced by multiple genes and environmental factors. When a trait is unifactorial, variations in that trait within a population can be directly attributed to different alleles of a single gene. Examples of unifactorial traits in humans include certain genetic disorders like cystic fibrosis or Huntington's disease, where a mutation in a specific gene leads to the manifestation of the condition. Similarly, simple Mendelian traits such as widow's peak or the ability to taste PTC are often considered unifactorial, though this can sometimes be an oversimplification as environmental influences or other genes might play minor roles. Understanding whether a trait is unifactorial or multifactorial is crucial for genetic counseling, predicting inheritance patterns, and researching the genetic basis of diseases and variations. The study of unifactorial traits has been fundamental to the development of classical genetics and continues to be important for identifying specific gene functions and their impact on phenotype.