Download Genetics and Health

Genetics and Health
Jennifer Eyvindson
Epi 6181
November 2006
Points to cover
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Basic Genetics
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Heredity
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Replication
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Translation
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Mutations
Genetics and Health
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Cancer
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Genes, behaviour, & social environment
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Tools to develop
Heredity
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Allele – a particular form of a gene
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We have 2 copies of each gene
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Homozygous – 2 copies of same allele
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Heterozygous – 2 different alleles
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Dominant (A) vs. Recessive (a)
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Incomplete Dominance
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Co-dominance
AA Aa aa
The basics
Chromosomes
 Condensed DNA
 Located in Nucleus
DNA
 Blueprint
The Double Helix
 Watson and Crick (1953)
 2 Strands of DNA
 Hydrogen bonds
Overview – Genetic processes
Replication (DNA  DNA)
Transcription (DNA  RNA)
Translation (RNA  Protein )
DNA Replication

DNA must be copied before every
cell division
Translation (protein synthesis)
1. Ribosome binds to DNA
2. tRNA binds to mRNARibosome complex and
brings Amino Acid
3. Amino Acid chain elongation
4. Protein
These Molecular Processes
are highly regulated:
Promoters
Inducers
Repressors
*Environment Influence
Protein Functions
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Structure & Mechanics
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Cell Structure
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Transport
Enzymes
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Catalyze chemical reactions
Signalers
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Hormones
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Receptors
When things go wrong
DNA
 Deletion
 Insertion
 Point mutation
PROTEIN
 Non-sense (STOP)
 Mis-sence
 Silent
It’s not that simple…
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Human Genome Project (April 2003)
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map and sequence 3 billion DNA base pairs
containing an estimated 30,000 genes
97% Non-coding “JUNK” DNA
Polygenetic Inheritance
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Most traits result from expression of more than
one gene
Gradients
Complex interactions not well understood
Genetics and Health
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Inherited
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Disorders
 Allele (Huntington's)
 X-linked (Hemophilia)
Other predispositions
 Allele variants (Addictions, Depression, Cancer…etc)
Errors
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Cancers
Chromosomal abnormalities (Down syndrome)
The Genetics of Cancer
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Tumours are the result of multiple
mutations
Mutations can be inherited or de novo
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Genetic Loss
 Regulatory
 Apoptosis (Cell self destruct mechanism)
 DNA repair
Genetic Gain
 Cell Cycle progression
 Apoptosis inhibitors
Genes, Behaviour, and the Social
Environment
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Top Down

Social factors influence genetics
Environmental mutagens lead to DNA
mutations and cancer
 Environment regulates gene expression

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Bottom up
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Genetics influence behaviors, thereby
the social environment
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Inherited traits predispose individuals to
act in certain ways
Tools to develop
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Bio Technology
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Informatics
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Look at multiple genes, proteins
Keep track of 30 000 genes and their
interactions
Laws and Ethics
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Genetic profiles ???