ECON 1 Lecture Notes - Lecture 14: Sex Linkage, Genomic Imprinting, Probability Distribution
Document Summary
Most psychological traits show patterns of inheritance that are much more complex than those of huntington disease or pku. Schizophrenia: 1 out of 100. (100 times more than huntington or pku, shows no simple pattern of inheritance. A special incidence figure used in genetic studies is called a morbidity risk estimate (lifetime expectancy), which is the chance of being affected during an entire lifetime. If several family members are affected greater risk: first degree relative (parent or sibling) 9, fraternal twins schizophrenic 17% Identical twins 48% the risk of developing schizophrenia increases systematically as a function of the degree of genetic similarity that an individual has to another who is affected. Heredity appears to be implicated, but the pattern of affected individuals does not conform to mendelian proportions. Many psychological traits are quantitative dimensions, as are physical traits such as height and biomedical traits such as blood pressure.