Genetics & Genetic Diseases :Genetics & Genetic Diseases


Origins of Modern Genetics :Origins of Modern Genetics Gregor Mendel Studied inheritance of characteristics in garden peas


Mendel’s First Experiment :Mendel’s First Experiment


Mendel’s Conclusions :Mendel’s Conclusions Hereditary characters are determined by discrete factors (genes) Genes appear in pairs, one from each parent Genes can occur in different forms (alleles) If members of gene pair are different (heterozygous), one allele will express itself (dominant allele) and the other will not (recessive allele)


Chromosomes :Chromosomes


Mitosis :Mitosis


Meiosis :Meiosis


Chromosomes: Carriers of Genes :Chromosomes: Carriers of Genes


Deoxyribonucleic Acid (DNA) :Deoxyribonucleic Acid (DNA)


DNA Structure :DNA Structure


DNA Replication :DNA Replication


Genes and DNA :Genes and DNA


Ribonucleic Acid :Ribonucleic Acid


Protein Synthesis :Protein Synthesis


Protein Synthesis :Protein Synthesis


Protein StructuredeterminesProtein Function :Protein StructuredeterminesProtein Function


Molecular Biology’s Central Dogma :Molecular Biology’s Central Dogma DNA RNA PROTEIN FUNCTION STRUCTURE


Mendelian Inheritance :Mendelian Inheritance Autosomal Recessive Autosomal Dominant X-linked Recessive X-linked Dominant Y-linked


Autosomal Recessive :Autosomal Recessive Either sex gets disease Siblings are usually affected, but not parents Heterozygotes of both sexes normal Heterozygote parents have diseased kids in ratio of 1:3 If defect involves a rare gene parents may be related


Autosomal Recessive :Autosomal Recessive Galactosemia Tay-Sachs Disease Cystic Fibrosis Albinism Phenylketonuria (PKU) Sickle Cell Anemia


Autosomal Dominant :Autosomal Dominant Affects males, females equally If you have the gene, you have the disease Every affected individual has an affected parent Normal siblings of affected individuals do not transmit disease (no unaffected “carriers”)


Autosomal Dominant :Autosomal Dominant Polydactyly Achoo Syndrome Huntington’s Disease Achondroplastic Dwarfism


X-linked Recessive :X-linked Recessive XA XA Xa Y Father’s Gametes Mother’s Gametes


X-linked Recessive :X-linked Recessive XA Xa XA Y Father’s Gametes Mother’s Gametes


X-linked Recessive :X-linked Recessive XA Xa Xa Y Father’s Gametes Mother’s Gametes


X-linked Recessive :X-linked Recessive More frequent in males Passed from affected males through their daughters No transmission directly from father to son Female carriers can express phenotype at variable levels


X-linked Recessive :X-linked Recessive Hemophilia Duchene Muscular Dystrophy Red/Green Colorblindness


X-linked Dominant :X-linked Dominant Xa XA Xa Y Father’s Gametes Mother’s Gametes


X-linked Dominant :X-linked Dominant XA Xa Xa Y Father’s Gametes Mother’s Gametes


X-linked Dominant :X-linked Dominant Affected males with normal spouses have normal sons and all affected daughters All offspring have 50% chance of being affected


X-linked Dominant :X-linked Dominant Faulty enamel trait


Y-linked :Y-linked X X X Y Father’s Gametes Mother’s Gametes


Y-linked :Y-linked Hairy ears


Non-Mendelian Inheritance :Non-Mendelian Inheritance Mitochondrial Traits Mitochondria contain multiple copies of a single DNA strand All mitochondria transmit through ova Mitochondrial traits pass from mother to child Disorders involve combinations of CNS, eye, and muscle tissue abnormalities


Non-Mendelian Inheritance :Non-Mendelian Inheritance Multifactorial Inheritance Do not involve single genes Pedigrees do not exhibit Mendelian patterns Frequently involve interaction between host, environmental factors


Multifactorial Disorders :Multifactorial Disorders Congential Neural tube disorders Cleft lip, palette Congenital heart disease


Multifactorial Disorders :Multifactorial Disorders Adult Coronary artery disease Type I diabetes Type II diabetes Breast cancer Colon cancer Lung cancer Rheumatic heart disease Alcoholism Multiple sclerosis Asthma, allergies Autoimmune disorders Bipolar disorder Schizophrenia Kidney stones Gallstones Obesity Peptic ulcer disease Gout


Coronary Artery Disease :Coronary Artery Disease Blood pressure Cholesterol Triglycerides HDL Weight Glucose Hypercholesterolemia Diabetes mellitus Smoking Stress Inactivity Diet Oral Contraceptives


Chromosomal Abnormalities :Chromosomal Abnormalities


Euploidy :Euploidy Addition, loss of complete chromosome sets Monoploidy (N) Polyploidy Triploidy (3N) Tetraploidy (4N) Fatal to Embryo


Aneuploidy :Aneuploidy Chromosome abnormalities not involving whole sets


Trisomy-21 :Trisomy-21


Down’s Syndrome :Down’s Syndrome 1 in 600 births Short, broad nose Epicanthal fold Small oral cavity Large, furrowed tongue Large, irregular teeth IQs from 20 to 50


Trisomy 13 :Trisomy 13


Patau’s Syndrome :Patau’s Syndrome 1 in 20,000 births Sloping forehead Small head, eyes Cleft lip, palate Heart defects 75% die in first year 100% by age 6


Trisomy 18 :Trisomy 18


Edwards’ Syndrome :Edwards’ Syndrome 1 in 11,000 births Small mouth, jaw Low-set, malformed ears Clinched fist, index finger overlapping 3rd, 4th fingers Rocker-bottom feet Heart defects Hearing loss 90% die by age 1


Kleinfelter’s Syndrome :Kleinfelter’s Syndrome


Kleinfelter’s Syndrome :Kleinfelter’s Syndrome 1 in 500 males Taller than average Partial breast development Small testicles, high-pitched voice, female hair distribution Altered body proportions, hips slightly larger than normal IQ about 90


Turner’s Syndrome :Turner’s Syndrome


Turner’s Syndrome :Turner’s Syndrome 1 in 2500 females Grow slowly Shield chest when young Low hair line Widely spaced nipples Fail to menstruate, no ova Normal IQ; weakness in math, spatial perception


Jacob’s Syndrome (XYY) :Jacob’s Syndrome (XYY) “Super Male” 1 in 1000 males 1 in 50 in prison populations Excessively tall (2/3s > 6 feet) IQs around 80 Low threshold for control of aggression


X-Polysomy (XXX, XXXX) :X-Polysomy (XXX, XXXX) XXX, 1 in 1400 females Cannot be distinguished from XX females Problems with spontaneous abortions XXX have normal IQs, increasing numbers cause mental deficiency