BIOL 3134 Lecture Notes - Lecture 4: 49,Xxxxy, Klinefelter Syndrome, Turner Syndrome
Document Summary
Inactivation is permanent: all descendants of a particular cells have the same x inactivated. Jacobs syndrome (47, xyy: 1/1,000 live male births, slightly taller (above 6 feet, persistent acne, xxyy syndrome (48, xxyy, 1/17,000 live male births, more severe symptoms compared to xxy. These disorders are a result of meiotic error and nondisjunction. Autosome abnormalities: karyotype may be abnormal in chromosome number or structure, polyploidy , aneuploidy abnormal number, cells with extra (trisomy) or missing (monosomy) chromosomes, out of 44 possible autosome abnormalities, only 4 types (autosomes) in newborns. Why: cells cannot survive with errors to most of the chromosomes, trisomy > monosomy, deletion, duplication, translocation. Swyer syndrome (46, xy: occurs in 1 of every 80,000 females, normal female external genitalia but all are infertile, mutation in the sry gene, or mutation in a gene controlling testicular developmental pathway with normal sry.
