DNA Unit 2 Lecture 2

DNA Unit 2 Lecture 2 Schizophrenia: spectrum trait from alleles of abnormal behavior that can’t tell what’s real ● 1% of population affected, but 40% chance if monozygotic twin is affected ● Biological makeup but also socially unfit, syndrome genetically based ● Study (Manhattan Plot) saw that a large fraction of genome is involved with one significant correlation. Increase sample size to find more detected loci ○ Not specific gene, but a broad genetic variation that influences complex health outcomes in our society, even with a larger sample size so still not statistically significant based on cutoff, repeat it ○ Take an arbitrary value to see cutoff, repeat again to see chances of it ○ VRCA: good gene but is gene for breast cancer if have certain genotypes ● Study: ignored GWAS and zoomed into 1 section SNPs to locate the affecting genes. Saw that only some people have rare gene that increases high risk for schizophrenia showing a cluster of SNPs ○ combined identified rare variants that have small effect on the population (heritability) but can have large effect on individuals ○ Common variants tend to have small effects on phenotypes ○ Rare variants have large effects on phenotypes (natural selection) ○ Claso Variants: influencing trait of influence that finds genetic variation that can’t be studied by GWAS studies as its too rare ● Both studies: overlap in some places show a cluster of SNPs gene associated with schizophrenia. Then locate protein mutations in that region for schizophrenia. Thus, the combination of both studies helps get closer to identifying causal genes. In this case, there was several genes that dealt with regulation of synapses in brain Take home Messages: ● More detailed GWAS studies = finding genetic pathways affecting complex traits ● Focusing on center GWAS genes “hits” = look for variants as even if rare, it can still have large effects ● Rare variants connect GWAS important areas of genome to specific genes that cause phenotype variation ● Helps understand and treat complex traits/diseases, but much more to be done Genetic Determinism in Social Space: GWAS increasingly used for personality attributes ● Any phenotype related to sociological data can be correlated to genome variation ● Study: sexual behaviors, Manhattan plot: less variation and higher threshold/cutoff ● Genetic Architecture: ~5 loci significantly correlated with behavior. Genetic variation explains 8-25% of phenotypic variance in M/F behaviors. ● Biological Processes: major genes involved in olfactory senses and sex hormones ○ If doubled sample, the genetic basis of straight will be more statistical genes ○ News “No gay gene” is a myth, being gay is natural, but says there's 5 genes ○ News article predicting happy marriage, naps, veggie taste, romance, etc. ■ Causes genetic/social inequality, controversial, race, education, $$ ● “The Genetic Lottery” book by Kathryne Harden: can’t deny genetic variation for traits, but not confine these traits socially, anti-racist. Can change IQ from genetics ○ Genes do not solely determine traits, but there is equal opportunity ● “The Bell Curve” book by Richard Herrnstein: high IQ have high income ○ social intervention must bridge those IQ gaps not genetics/race ● Charles Murray: studying of IQ that has a genetic basis, heritability of IQ is no longer pretentious, but is a description of how genetic variation is in our complex lives ○ Discredits previous beliefs, IQ scores are heritable so has genetic variation so it can be modified/improved ○ Gaps can be fixed not strictly by genetic reasons, IQ has increased over time ○ inequalities of $$ and race has decreased, countering genetic essentialism Take Home Messages ● A more detailed follow up from GWAS studies offers promise for finding the genetic pathways affecting complex traits ● Genes = center of GWAS “hits” scientists to look for variants w/rare & large effects ● These rare variants connect the dots between GWAS which points to important areas of the genome, to specific genes that cause variation in phenotypes ● These propel our understanding/treating complex traits/disease, but much to do