Genetics and Health

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Genetics and Health

• Jennifer Eyvindson
• Epi 6181
• November 2006

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Points to cover

• Basic Genetics
• Heredity
• Replication
• Translation
• Mutations
• Genetics and Health
• Cancer
• Genes, behaviour, social environment
• Tools to develop

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Heredity

• Allele a particular form of a gene
• We have 2 copies of each gene
• Homozygous 2 copies of same allele
• Heterozygous 2 different alleles
• Dominant (A) vs. Recessive (a)
• Incomplete Dominance
• Co-dominance

AA Aa aa
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The basics

• Chromosomes
• Condensed DNA
• Located in Nucleus
• DNA
• Blueprint
• The Double Helix
• Watson and Crick (1953)
• 2 Strands of DNA
• Hydrogen bonds

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Overview Genetic processes
Replication (DNA ? DNA)
Transcription (DNA ? RNA)
Translation (RNA ? Protein )
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DNA Replication

• DNA must be copied before every cell division

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Translation (protein synthesis)

• 1. Ribosome binds to DNA
• 2. tRNA binds to mRNA-Ribosome complex and brings
  Amino Acid
• 3. Amino Acid chain elongation
• 4. Protein

These Molecular Processes are Highly regulated
Promoters Inducers Repressors Environment
Influence
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Protein Functions

• Structure Mechanics
• Cell Structure
• Transport
• Enzymes
• Catalyze chemical reactions
• Signalers
• Hormones
• Receptors

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When things go wrong

• DNA
• Deletion
• Insertion
• Point mutation
• PROTEIN
• Non-sense (STOP)
• Mis-sence
• Silent

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Its not that simple

• Human Genome Project (April 2003)
• map and sequence 3 billion DNA base pairs
  containing an estimated 30,000 genes
• 97 Non-coding JUNK DNA
• Polygenetic Inheritance
• Most traits result from expression more than one
  gene
• Gradients
• Complex interaction not well understood

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Genetic and Health

• Inherited
• Disorders
• Allele (Huntington's)
• X-linked (hemophilia)
• Other predispositions
• Allele variants (Addictions, Depression,
  Canceretc)
• Errors
• Cancers
• Chromosomal Abnormalities (Downs syndrome)

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The Genetics of Cancer

• Tumours are the result of multiple mutations
• Mutations can be inherited or de novo
• Genetic Loss
• Regulatory
• Apoptosis (Cell self destruct mechanism)
• DNA repair
• Genetic Gain
• Cell Cycle progression
• Apoptosis inhibitors

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Genes, Behaviour, and the Social Environment

• Top Down
• Social factors influence genetics
• environmental mutagens lead to DNA mutations and
  cancer
• Environment regulates gene expression
• Bottom up
• Genetics influence behaviors, social environment
• Inherited traits predispose individuals

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Tools to develop

• Bio Technology
• Look at multiple genes, proteins,
• Informatics
• Keep track of 30 000 genes and their interactions
• Laws and Ethics
• Genetics profiles ???