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 #: Long to Short
Chromosome Arms and Centromere
Homologous Chromosomes
Homozygous and Heterozygous
Phenotype and Genotype
Carrier, Dominant, Recessive
Chromosome structure
Chromosome vs Chromatin
Looped Domains and Chromatin
Histones and Nucleosomes
Gene
1.5% of Genome DNA base pairs (~ 100,000) Encode a product
(protein, tRNA, rRNA)
Responsible for a measurable trait
Introns Exons
Cell Cycle Review
Mitosis and Meiosis Compared
Meiosis I: Normal
Chromosome Disorders Chromosome Number
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
Extra Chromosomal Disorders
Down Syndrome (Trisomy 21)
Chromosome Abnormalities
Structure Break and
reassemble abnormally
Inversion Translocation Insertion Deletion Duplication
Translocation in Meiosis
Insertions and Deletions
Deletion
1, 2, or 3 base pairs are deleted
Frameshift reading
Chromosome Deletions
Prader-Willi / Angelman Syndromes
Cancers caused by Deletions
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
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
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
Spontaneous Mutations
Depurination Deamination Oxidation
damage to DNA
Spontaneous Mutations in the population
Depurination and Deamination
Depurination Deamination
Induced Mutations
Mutagentic Base Analog
Chemical Agents Ultraviolet
Radiation Ionizing Radiation
Induced Mutations
Base Analog Mutagen
UV
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 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 brain image
Polycystic Kidney Disease
PKD
Cat kidney Human 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
Autosomal Dominant Gene Therapy
Autosomal Recessive
Albinism 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
Disease Symptoms
DMD (Xp21) 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
Duchenne Muscular Dystrophy
Absence of Dystrophin causes membrane to leak CPcausing 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
Gene Map of Disease Loci
Chromosome 4 Conditions
Epigenetic Alterations
Methylated DNA is inactivated
Mitochondrial DNA (mtDNA)
Chromosomes in Mitochondria
Heavy Strand
Light Strand
Inheritance Patterns Compared
Results of Inheritance Patterns
Mitochondrial DNA disorders
Mitochondrial Genetic Diseases
Additional Terminology
Congenital Defect Mutagen Teratogen Carcinogen Hot Spots Cloning
Karyotyping of Sample
Genetic Counseling