Learning Objectives

• Appreciate Falconer’s threshold model, a hypothetical scale of disease liability
• Apply Falconer’s liability model to determine a patient’s risk of disease
• Understand the varied factors influencing complex qualitative traits
• Explain the concept of liability in complex qualitative traits

Genetic Traits

• what is a complex genetic trait?
• what is a qualitative complex trait? examples?
• do qualitative traits follow Mendel's laws? explain?
• what is meant by discontinuous phenotypic variation?
• what is concordance vs disconcordance?
• what terms are used for 'similarity' and 'measure' in quantitative vs qualitative traits?
• what is heritability?

Threshold Model

• what is susceptibility?
• what is liability?
• how does liability relate to threshold?
• what is a threshold trait?
• what is Falconer's threshold model?