Human Genetic Variation Flashcards
What are the limitations to human genetics?
Small families, long generation times
What is a polymorphic locus?
Many different forms at a given region of the genome
What is a rare variant?
Variants that have a frequency of less than 1% in the population
What is the first human genetic polymorphism discovered?
ABO blood group
What two factors are blood groups defined by?
Antigens carried on the blood cell and antibodies carried in the serum of the blood
What is an universal donor and what blood group is one?
Blood group O - have no antigens carried on the blood cell and so can take their red blood cells and donate to any individual without having an immune response
What is an universal recipient and what blood group is one?
Blood group AB - have no antibodies in the serum and so can receive blood cells from any other blood group without having an immune response
What does the ABO blood group system correspond to?
Carbohydrates emanating from the surface of red blood cells
Why did Rh- women second or subsequent pregnancy lead to still birth?
Husband - Rh+
First child - Rh+
Anti-Rh in mother leading to haemolysis of next Rh+ child
What can you detect migration through starch gels with?
Protein stain
Enzyme stain
Antibody
What does RFLPs stand for and what are they?
Restriction fragment length polymorphism
Variable restriction sites due to mutations creating or destroying restriction sites
Where do RFLPs occur?
All regions - exons, introns, intergenic and pseudo regions
How do you traditionally detect RFLPs?
Restrict genomic DNA, agarose gel electrophoresis, Southern blot, hybridise with probe
How big are minisatellite arrays and repeat units?
Arrays: 0.5-30kb
Repeat units: 6-100bp
How do minisatellites mutate?
Recombination based processes - unequal crossing over and gene conversion
