《医学遗传学 Medical Genetics》课程授课教案（PPT课件讲稿）第六讲 疾病的多基因遗传 Monogenic Inheritance

Medical Genetics 06疾病的多基因遗传 Monogenic Inheritance

Medical Genetics 06疾病的多基因遗传 Monogenic Inheritance

Medical Genetics Multifactorial inheritance is responsible for the greatest number of individuals that will need special care or hospitalization because of genetic diseases

Medical Genetics Multifactorial inheritance is responsible for the greatest number of individuals that will need special care or hospitalization because of genetic diseases

Medical Genetics Up to 10% of newborn children will express a multifactorial disease at some time in their life. Atopic reactions, diabetes, cancer, spina bifida/anencephaly, pyloric stenosis, cleft lip, cleft palate, congenital hi dysplasia club foot, and a host of other diseases all result from multifactorial inheritance

Medical Genetics Up to 10% of newborn children will express a multifactorial disease at some time in their life. Atopic reactions, diabetes, cancer, spina bifida/anencephaly, pyloric stenosis, cleft lip, cleft palate, congenital hip dysplasia, club foot, and a host of other diseases all result from multifactorial inheritance

Medical Genetics Some of these diseases occur more frequently in males. Others occur more frequently in females Environmental factors as well as genetic factors are involved

Medical Genetics Some of these diseases occur more frequently in males. Others occur more frequently in females. Environmental factors as well as genetic factors are involved

Medical Genetics 1. REGRESSION TO THE MEAN Multifactorial inheritance was first studied by Galton a close relative of darwin and a contemporary of Mendel. Galton established the principle of what he termed regression to mediocrity

Medical Genetics 1. REGRESSION TO THE MEAN Multifactorial inheritance was first studied by Galton, a close relative of Darwin and a contemporary of Mendel. Galton established the principle of what he termed "regression to mediocrity

Medical Genetics Galton studied the inheritance of continuous characters height in humans, intelligence in humans etc

Medical Genetics Galton studied the inheritance of continuous characters, height in humans, intelligence in humans, etc

Medical Genetics Galton noticed that extremely tall fathers tended to have sons shorter than themselves, and extremely short fathers tended to have sons taller than themselves, Tallness or shortness didn't breed true like they did in Mendel's regress to the median, or "mediocrity cO pea experiments. The offspring seemed to

Medical Genetics Galton noticed that extremely tall fathers tended to have sons shorter than themselves, and extremely short fathers tended to have sons taller than themselves. "Tallness" or "shortness" didn't breed true like they did in Mendel's pea experiments. The offspring seemed to regress to the median, or "mediocrity

Medical Genetics 80° Height 68 S on 60 60 68 80 Height of father

Medical Genetics

Medical Genetics When comparing height differences between men and women women are, on average, 3 inches shorter. a woman with a certain number of" genes will be, on average 3 inches shorter than a man with the same number. when that difference is taken into account there is no selective bias in matings for tallness in human populations

Medical Genetics When comparing height differences between men and women, women are, on average, 3 inches shorter. A woman with a certain number of "tall" genes will be, on average, 3 inches shorter than a man with the same number. When that difference is taken into account, there is no selective bias in matings for tallness in human populations

Medical Genetics It is true than men tend to marry women who are shorter than themselves but that is a phenotypic difference, not a genotypic difference. Since the wives of taller than average men tend to represent the general population of women, they wi not have on the average, as many"tall genes to pass on to their offspring as their husbands

Medical Genetics It is true than men tend to marry women who are shorter than themselves, but that is a phenotypic difference, not a genotypic difference. Since the wives of taller than average men tend to represent the general population of women, they will not have, on the average, as many "tall" genes to pass on to their offspring as their husbands