- Autosomal dominant - the disease carries in one of the 22 chromosomes that's not a sex chromosome, and because it's dominant having one copy is sufficient to produce the disease phenotype.
- In this type of inheritance pattern, half the offspring would get the disease.
- Variable penetrance - not every person who has the genetic abnormality will get the disease.
- Autosomal recessive -
- With diseases carried on recessive genes, both parents have to carry the gene with disease and both have to pass it on, so this would affect about 25% of offspring.
- This mostly happens when parents are related, or when the gene that carries disease is common in the entire population.
- Why children's DNA varies from parents:
- To start, you get one chromosome from each parent
- Then, each of us has about 100 De Novo mutations (usually 1 in coding regions).
- Over generations, the DNA looks less and less like ancestors.
Genome Wide Association
- 30 million base pairs - lots to cover. But now you can get it done for a couple hundred dollars.
- This is a way to study genetic variance with large population rather than family history - you find the phenotype first and then check their genes.
- He gave examples of different phenotypes located on different chromosomes, and one of the examples was that variations on the 4th chromosome are 3 times more likely to cause atrial fibrillation. (But it's still unusual.)
- Uses for Genome wide association studies:
- Analyze heritability
- Identify new drug targets
- Predict risk (single or multiple variants)
- Subclassify disease
- Understand and maybe prevent adverse drug reactions
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