Review and Alterations Genetics Review and Alterations
Terminology Chromosome: types, number Haploid, Diploid Gene, Allele, Loci Homozygous, Heterozygous Karyotype, Phenotype, Genotype Carrier, Dominant, Recessive Nucleic Acids, Base Pairs Replication: DNA, mitosis, meiosis Protein Synthesis Transcription Translation
Chromosome Pairs in Species
Chromosome Types
Chromosome #: Long to Short
Human Karyotype
Chromosome Arms and Centromere
Homologous Chromosomes
Allele and Loci
Homozygous and Heterozygous
Phenotype and Genotype
Carrier, Dominant, Recessive
Chromosome structure
Chromosome vs Chromatin
Looped Domains and Chromatin
Histones and Nucleosomes
DNA
DNA structure
Gene 1.5% of Genome DNA base pairs (~ 100,000) Encode a product (protein, tRNA, rRNA) Responsible for a measurable trait Introns Exons
DNA Base Pairs
Nucleoside
DNA Replication
Cell Cycle Review
Mitosis
Meiosis
Mitosis and Meiosis Compared
Meiosis I: Normal
Non Disjunction
Chromosome Disorders Chromosome Number Trisomic (n + 1) Euploid (2N) Polyploid (exact multiple) Triplody (3N) Tetraplody (4N) Anueploid (not exact multiple) Trisomic (n + 1) Autosomes Down’s Syndrome Sex Chromosomes Klinefelter Monosomic (n-1) Sex Chromosome Turner Mosaics (not all cells affected) Somatic Gonadal
Anaphase
Extra Chromosomal Disorders
Down Syndrome (Trisomy 21)
Anueploid
Chromosome Abnormalities Structure Break and reassemble abnormally Inversion Translocation Insertion Deletion Duplication
Inversions
Translocations
Translocation in Meiosis
Insertions and Deletions
Insertion
Deletion 1, 2, or 3 base pairs are deleted Frameshift reading
Chromosome Deletions
Deletion example
Prader-Willi / Angelman Syndromes
Cancers caused by Deletions
Wilms Tumor
Duplications Doubling section of genome Unequal Crossing over Multiple repeats of nucleotides
DNA section duplicated Huntington’s CAG repeated Fragile X CGG repeated MD CTG repeated
Chromosomal Mutation Summary
DNA Transcription
Transcription Steps
Translation
DNA codon for AA
DNA Damage
Mutation: Define S phase Types Single Base Pair substitution Missense Nonsense Silent Frame shift Spontaneous Induced
Base Pair Substitution (point mutation) Transition Purine for Purine Pyrimadine for Pyrimadine Transversion Purine for Pyrimadine Pyrimadine for Purine
Transition
Nonsense Mutation Transversion: UGC to UGA Nonsense mutations result in stop codons
Nonsense Mutations Codon changed Stop codon is read TAA TAG TGA
Missense Mutation Transversion: UGC to UGG
Missense Mutation Miscoding of AA can lead to diseases such as SSA and CF
Silent Mutation
Frame Shift
Mutation Summary
Spontaneous Mutations Depurination Deamination Oxidation damage to DNA
Spontaneous Mutations in the population
Depurination and Deamination
Induced Mutations Mutagentic Base Analog Chemical Agents Ultraviolet Radiation Ionizing Radiation
Induced Mutations UV Base Analog Mutagen
Ionizing Radiation
Mendelian Inheritance Patterns Dominant / Recessive CoDominance Incomplete Dominance Sex Linked Multifactoral
Dominant, Recessive, Sex-linked
Sex-Linked Punnett Square
CoDominance: Blood Types
Incomplete Dominance: SSA
Incomplete Dominance: OI
Genetic Disorders: Single Gene Autosomal Dominant Autosomal Recessive X-linked dominant X-linked recessive
Hereditary Map of Autosomal Dominant Traits
Autosomal Dominant Achondroplastic dwarfism vonWillibrand’s Disease Abnormal endochondrial bone formation causing dwarfism vonWillibrand’s Disease Factor VIII defect causing bleeding disorders Neurofibromatosis Increased neurofibromatoma Polycystic Kidney Disease Cystic enlargement, hematuria, hypertension, and possible renal failure Alzheimers (10% of cases) dementia Machado-Joseph Spinocerebellar degeneration Marfan syndrome Abnormal fibrillin causing excessive bone growth, ocular disorders, & cardiac defects
Huntington Disease Basal ganglia
Huntington brain compared to normal
Hydrocephalus
Hydrocephalus brain image
Polycystic Kidney Disease
PKD Human kidney Cat kidney
Neurofibromatosis
Neurofibromatosis Clinical Signs
Marfan Syndrome Abnormal fibrillin, Affects elastic C.T.
Osteogenesis Imperfecta
Autosomal Dominant: Metabolic Familial hypercholesterolemia Acute intermittent porphyria
Familial Hypercholesterolemia
Polydactylia
Autosomal Dominant Gene Therapy
Autosomal Recessive Albinism Sickle Cell Anemia Tyrosine can not be changed to melanin for pigment Sickle Cell Anemia Amino acid substitution in beta chain of hemoglobin, sickling
X and Y Chromosomes
X-linked Disease Pedigree
Sex-Linked
Sex Linked Disease Symptoms DMD (Xp21) Menkes (Xq12-q13) Muscular weakness and degeneration due to lack of dystrophin protein Menkes (Xq12-q13) Copper storage disease that leads to neurodegeneration and CT disorders Color Blindness Defective function of cones for red and green color vision Hemophilia A (Xq28) Bleeding disorder due to a Factor VIII deficiency Fabry (X Temperature intolerance, enlarged heart, whole body pain, depression, vomiting / diarrhea SCID (Xq13.1) Immune deficiency impairment, death
X-linked Diseases
Hemophilia
Duchenne Muscular Dystrophy Absence of Dystrophin causes membrane to leak CP causing weakness associated with DMD
X-Linked SCID Inheritance Most common form Mutation in IL-2 receptor gene Lymphopenia Absence of T cells Absence of NK cells Abnormal B cells
Other X-linked Immune Diseases
Loci on X and Y Chromosomes
Fun Y Chromosome loci
Multifactoral Inheritance Several Genes Environmental factors Cluster in families Examples Cleft lip or palate Congenital heart disease Club foot Pyloric Stenosis
Multifactoral
Gene Map of Disease Loci
Chromosome 4 Conditions
Epigenetic Alterations Methylated DNA is inactivated
Gene Expression
Cell Cycle
Mitochondria
Mitochondrial DNA (mtDNA)
Chromosomes in Mitochondria Heavy Strand Light Strand
DNA compared
Inheritance Patterns Compared
Results of Inheritance Patterns
Mitochondrial DNA disorders
Mitochondrial Genetic Diseases
Additional Terminology Congenital Defect Mutagen Teratogen Carcinogen Hot Spots Cloning
Genetic Testing
Karyotyping of Sample
Genetic Counseling
Gene Therapy
Questions?