Psych 350 1st Edition Lecture 6 Outline of Last Lecture I Meiosis II Genotype III Autosomal recessive disorder IV Autosomal dominant disorder V Sex linked disease Outline of Current Lecture I Down syndrome II Norm of Reactions III Simple Genetic a PKU b Fragile X syndrome c Williams syndrome IV Genotype variance Current Lecture down syndrome associated with risk of mothers age after the age of 35 norm of reactions genes don t specific a particular outcome but a range of outcomes three genetic disordered simple genetic don t need to know details of these disorders PKU autosomal recessive 12th chromosome400 different mutations of this gene that is known fragile x syndrome codes for FMRP insertion of egg repeat 5 to 40 repeats normal but if you have over 200 you have the syndrome lots of people have 55 to 200 pre mutation Williams syndrome deletion on 7th chromosome involves 20 to 25 genes different kids have different disabilities These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute variability of whats going onPKU single disease but there are 400 typesfragile x over 200 but there is a lot of variability could have 200 or 400 can have different expression of protein William s deletion occurring at different points have different characteristics A LOT OF VARIANCE IN A SINGLE DISEASE just consider genetics there is a lot of variance and have a lot of variance in outcome doesn t have down syndrome but trisomy 18 Edward syndrome range of outcomes is extreme three quarters of fetuses don t survive until birth half the kids die within the first week 1 percent of the kids survive mental retardation delayed motor control genotype genes involve in disorders are heterogeneous phenotype is heterogeneous genotype other inherited genes family and resources community phenotypetake home message inherit gene you get disorder no all the things above effect outcome make huge range of outcomes possible gene isn t going to cause a specific outcome cause a range of outcomes what that range is is dependent on that gene as well as other factors sickle cell anemia autosomal recessive disorder that involve an impairment of the blood to transport oxygen to the tissue risk of sickle cell is much higher if african or Mediterranean because it has a beneficial effect on individuals where there is a lot of malaria much les likely to get malaria or get as bad as systems graphically live in africa have normal genotype without sickle cell have a range of illness and get sick with malaria get sick blue bar live in africa and have sickle cell trait be protected from malaria and be healthier than the person without sick celllive in USA have normal no sickle cell systems healthierlive in USA and have sickle cell sicker range of outcomes if you have sickle cell trait live in africavs USA interaction of genetic trait with environment in africa it is good but usa it is bad interaction between genotype and the environment depending where you live GENES ARE NOT SPECIFIC OUCOME RANGE OF OUTCOMES bad gene depends on genotype environment family genetics of mental disorders genetic base of phycological disorders had a model ten years ago saying it is a single gene disorder but it is not true transcript of all human genes and known that there is no single gene that causes these psychological disorders there are some rare autistic like disorders that are single gene but that is less than 1 percent of people with ASD found that there is 100 of different genes involved ASD 200 genes involved in autism there are probably 500 1000 genes involved in the increased risk of autism no single gene that is involves in a large fraction of the disorder two cases rare genetic variance if inherit that variant then it is highly like to show symptoms more common genetic variance but they don t increase the risk a lot could have inherited mutation in DNA when egg was fertilized and increased changes a lotcould have had a common mutation floating in our DNA and each of the mutations have a small chance of increase risk of autism genetic variance are associated with increase in risk for a variety of different disorders ex autism and schizophrenia they doesn t specifically one disease data list of much of genes associated with Autism phenotype not in terms of disease but the behaviorexact pattern they will show depends on the genes they inherit environment prenatal things inherent one of the genes not going to cause the disorder but going to drop your levels like drop iq from being average to being below average but the rest of the developments would be averageall kids who inherent these genes will have different expectations but it depends on family can show clinical systems but sometimes it wont reach the clinical range traditional behavior genetics stuff above is not in this classification relating families and twin studies to diseases like autism and iq go back to the late 1900s to Galtonh noticed a lot of variance in traits genetic differences between people like iq height and weight study twins identical twins came from same egg have same genes fraternal twins two different eggs are fertilized difference between siblings and them is that they are born at the same time monozygotic identical if compare twin types id twins are more similar height hair is very similar f twins are different compare rate of correlation between twins id twin you have 48 chance f twin you have 17 chance of havinghave some genetic basis develop model to estimate how strong the genetic basis was for the disorder