BSCI 10001 Lecture Notes - Lecture 17: Nondisjunction, Retinitis Pigmentosa, Hypertrichosis
28 Apr 2019
School
Department
Course
Professor
Document Summary
The human x chromosome contains some 1,400 genes. Over 59 diseases are due to mutant alleles of some of these genes, including duchenne muscular dystrophy, a form of retinitis pigmentosa, agammaglobulinemia, fragile-x syndrome, several forms of color blindness, and a form of hemophilia. The only known y-linked trait: hairy ear rims. Hemophilia is a good example of the heredity patterns in humans of a recessive x-linked disease. The wild type allele codes for an enzyme used in blood clotting; blood in boys with the defective allele fails to properly clot. A particularly well-documented example of the genetics of this genetic disease is the high frequency of x-linked hemophilia that plagued the intermarrying royal families of europe in the last century. The recessive allele for hemophilia seems to have arisen in an x-chromosome of one of queen victoria"s parents, making victoria a heterozygote carrier of the deadly allele.
