28th February 2024

Multifactorial inheritance

Multifactorial inheritance is a catch-all term whereby a condition appears to be influenced by multiple genetic loci. This is commonly associated with many common conditions with multiple predisposing factors like cancer, cardiac conditions, asthma, and mental illness.

The liability threshold theory has been proposed to explain multifactorial inheritance. Genetic and environmental factors must be combined before the phenotype is expressed.

Large Scale population studies can be used to study and estimate the risk of recurrence within a family, but environmental factors prevent the generalisation of such results. Studies between monozygotic and dizygotic twins have been utilised to study various traits and allow the heritability of various conditions to be estimated.