BIOLOGY 2C03 Study Guide - Final Guide: Trinucleotide Repeat Disorder, Linkage Disequilibrium, Nancy Wexler
30 Nov 2017
School
Department
Course
Professor
Document Summary
Clinical description of disease wide range of onset (age 2-90), but typically appears in late 40"s or 50"s degenerative disorder that takes about 15 years before eventually leading to death. Transitional phase - loss of ne motor control, slurring of speech, constant involuntary movements (chorea) Advanced phase - loss of ability to walk, speech becomes incomprehensible, patients can no longer swallow, memory becomes impaired. Complete penetrance - if an individual carries the mutation, they will eventually show the symptoms average age of death is 60 due to infection of pneumonia. 1978: nancy wexler attempts to identify the a ected gene in collaboration with james gisela as massachusetts. 8th probe tested showed linkage! disease allele mapped to the short arm of chromosome 4 (4p16. 3) The more repeats, the earlier the onset and increased rate of progression, but the number of repeats does not correlate with increased overall severity.
