lecture 20- mapping disease through mendelian approaches Flashcards
human genome project
launched in 1990 to sequence the first complete human genome
massive parallel methods (next gen sequencing)
revolutionizing sequencing providing faster and cheaper genomes
genome centers
operate highly automated production lines, increasing genomic output
snp (single nucleotide polymorphisms)
places where 1 base pair is different (changes amino acids, changes protein)
ex: glutamic acid to valine causes sickle cell
short tandem repeats (genetic markers)
regions in the genome where there are many repeats
ex: over 30 CAG repeats- huntington (repeats are likely to make mutations because there are so many similar things)
copy number variants
long region of the genome where you may have different numbers of copies
ex: alpha thalassemia
cystic fibrosis
Cystic fibrosis (CF) is a genetic disorder that causes problems with breathing and digestion. CF affects about 35,000 people in the United States. People with CF have mucus that is too thick and sticky, which. blocks airways and leads to lung damage; traps germs and makes infections more likely
each person has a gene called
CFTR. That gene encodes a protein that functions as a channel that
allows chloride ions to travel across cell membranes. When a mutation
occurs that inactivates the CFTR gene, the protein no longer performs its
function, causing improper ion concentrations inside and outside their
cells. Thus, a person with CF does not properly produce sweat, digestive
juices, and mucus.
breakthroughs in diagnosis and etiology of cf
cftr (cystic fibrosis gene)
How many genes do we have
20,000
mendelian genetics approach to disease mapping
uses small datasets to investigate single gene/simple traits
population genetic approach to disease mapping
uses large datasets to investigate complex traits
why cant qtl mapping be done in humans
cant ethically do a backcross or intercross unlike fruit flies
steps of a linkage analysis study
STR (short tandem repeats)
useful for linkage analysis as they are highly polymorphic