Monofactorial

Monofactorial refers to a characteristic, trait, or condition that is determined by a single gene. In genetics, the term describes a situation where a particular phenotype is the result of the inheritance of alleles at just one locus. This contrasts with polygenic traits, which are influenced by multiple genes. Understanding whether a trait is monofactorial is crucial for predicting inheritance patterns and diagnosing genetic disorders. For example, conditions like cystic fibrosis and Huntington's disease are considered monofactorial because they are caused by mutations in a single specific gene. Pedigree analysis is often used to determine if a trait is inherited in a simple, monofactorial manner, looking for clear patterns of transmission through generations. While many traits are indeed monofactorial, it is important to note that environmental factors can sometimes interact with even single-gene determinants, leading to variations in expression. However, the primary underlying cause remains the single gene in a strictly monofactorial scenario.