ECON 1 Lecture Notes - Lecture 14: Heritability, Genetic Testing, Coronary Artery Disease
Document Summary
Mendelian inheritance: caused by mutation in 1/both copies of single nuclear gene, classic inheritance patterns dominant/recessive or autosomal/x-linked. Non-mendelian inheritance: multifactorial, maternal (mitochondrial, polygenic. Majority of people w/ common disorder due to multifactorial inheritance. Common conditions genetic component suggested by clustering of cases in fam but no obvious inheritance pattern: coronary artery disease, diabetes mellitus, hypertension, cerebrovascular disease, schizophrenia, breast/bowel cancer, congenital abnormalities. Mendelian conditions genetic component highlighted by pedigree pattern & recurrent risk: hypercholesterolaemia, marfan syndrome, cf, sickle cell, duchenne muscular dystrophy, some types of diabetes. Family history/genetic testing help decide aetiology in person/fam. Completely genetic rare, unifactorial & high recurrence rate. Completely environmental common, multifactorial & low recurrence rate. Need to know relative contribution of genetic/environmental factors: for target treatment, alter environment for people w/ genetic susceptibility. Use observational studies of incidence of diseases in diff groups of people. Familial clustering is incidence in relatives different from that of general public. Twin studies incidence in monozygotic vs dizygotic.
