《医学遗传学》课程PPT教学课件（留学生 Medical Genetics）03 Chapter Monogenic Disease

The Third Chapter The Monogenic Disease

The Third Chapter The Monogenic Disease

Contents > Basic concepts and research methods of monogenic The basic genetics style of monogenic disease Influence factors of monogenic disease analysis Recurrence risk assessment of monogenic disease

Contents ➢ Basic concepts and research methods of monogenic ➢ The basic genetics style of monogenic disease ➢ Influence factors of monogenic disease analysis ➢ Recurrence risk assessment of monogenic disease

OMIM Statistics for Sept.13,2005 X Autosomal 15212 X-linked 906 Y-linked 56 Mitochondrial 62 16236 http://www.ncbi.nlm.nih.gov/Omim/mimstats.html

OMIM Statistics for Sept. 13, 2005  Autosomal 15212  X-linked 906  Y-linked 56  Mitochondrial 62 16236 http://www.ncbi.nlm.nih.gov/Omim/mimstats.html

Basic concepts of monogenic Alleles:alternate versions of the same gene Contributes to genetic variation GOOD. Homozygous:same allele from mom and dad ■Ex:AA,aa Heterozygous:different allele from mom and dad ■Ex:Aa,Bb Hemizygous:sex chromosomes are different Homomorphic (XX female),heteromorphic (XY male)

Basic concepts of monogenic ◆ Alleles: alternate versions of the same gene ◼ Contributes to genetic variation = GOOD. ◆ Homozygous: same allele from mom and dad ◼ Ex: AA, aa ◆ Heterozygous: different allele from mom and dad ◼ Ex: Aa, Bb ◆ Hemizygous: sex chromosomes are different ◼ Homomorphic (XX female), heteromorphic (XY male)

Allele for purple flowers Locus for Homologous flower-color pair of gene chromosomes Allele for white flowers CopyrightPearson Education,Incpublishing as Benjamin Cummings

纯合子 纯合子 杂合子 图32纯合子与杂合子

Basic concepts of monogenic Genotype>genetic makeup or allelic constitution of an individual ■AA,Aa,aa,etc. Phenotype>the expression or appearance of an individual AA and Aa would have the same phenotype, although their genotype is different

◆ Genotype→ genetic makeup or allelic constitution of an individual ◼ AA, Aa, aa, etc. ◆ Phenotype→ the expression or appearance of an individual ◼ AA and Aa would have the same phenotype, although their genotype is different Basic concepts of monogenic

Basic concepts of monogenic Character:A term for a heritable feature (i.e,flower color,wing types,hair type,etc.) Trait:Each variant for a character (i.e,red and white for flower color;wild and vestigial for wing types; straight and curly hair for hair types,etc.)

◆ Character: A term for a heritable feature (i.e, flower color, wing types, hair type, etc.) ◆ Trait: Each variant for a character (i.e, red and white for flower color; wild and vestigial for wing types; straight and curly hair for hair types, etc.) Basic concepts of monogenic

Basic concepts of monogenic Dominant -A Recessive—a Homozygote -AA or aa Heterozygote -Aa Genotype Phenotype

Basic concepts of monogenic Dominant —— A Homozygote —— AA or aa Heterozygote —— Aa Genotype & Phenotype Recessive —— a

Basic concepts of monogenic ◆Nild type vs.mutant ■Nild type is“normal''expression of trait Mutant is not normal,or mutated Ratios:proportion of offspring that have a given genotype or phenotype Show modes of inheritance AA,Aa,aa 1:2:1 genotypic,3:1 phenotypic

◆ Wild type vs. mutant ◼ Wild type is “normal” expression of trait ◼ Mutant is not normal, or mutated ◆ Ratios: proportion of offspring that have a given genotype or phenotype ◼ Show modes of inheritance ◼ AA, Aa, aa = 1:2:1 genotypic, 3:1 phenotypic Basic concepts of monogenic