HMB265H1 Lecture 4: Mendelian Traits in Humans & Human Pedigree Analysis (Sept. 23, 2016)

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Lecture notes: mendelian traits in humans & human pedigree analysis. Albinism follows the same 3:1 phenotypic rule, for example. Albinism, for example, is caused by lack of melanin. Tyrosine is converted by an enzyme into melanin. With only one wild type, it is haplosufficient. Those who have two recessive mutations cause albinism. Autosomal traits are located on non-sex chromosomes (1-22 out of 23) Inherited as either dominant or recessive, akin to mendelian traits. Affected gene is dominant - note that affected does not necessarily mean bad Males and females are equally affected and may transmit the trait. Males & females are equally affected and may transmit the trait. Model organisms and pedigrees used to investigate traits of interest. Pedigrees are an orderly diagram of family"s genetic features through multiple gens. Helps us infer if trait is from single gene and if trait is recessive or dominant. Propositus - person of interest that started the construction of pedigree.