Transcript Genetic Red Flags

What did I inherit from my parents?
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Today’s Objectives:
Review basic genetic concepts
Create family health tree
Identify patterns suggesting genetic link
Introduce genetic testing
Why is understanding of genetics
important?
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“Blue print” for your life
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Understand your potential health risk or predisposition
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Understand health strengths
Why is understanding of genetics
important?
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Human Genome Project
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Increasing testing options
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Current media – family of 4 had complete genome
sequenced
Policy decisions
23 and ME
Tests for multiple different genetic
markers
Marketed to:
Discover disease risk
factors
Screen for carrier status
Know your predicted
response to drugs
Also
Trace your ancestral
lineage
Find and connect with
family members
Uncover your heritage
WHAT IS ACTN3 Sports Gene™?
Atlas First SportGene® Test is geared specifically
to show athletes, trainers and interested individuals
where their genetic advantage lies. Atlas First looks
at only genetic markers, specifically the ACTN3
gene. Studies have found that individuals having
the R577X variant in both copies of their ACTN3
gene may have a natural predisposition to
endurance events, in one copy of their ACTN3
gene may be equally suited for both endurance and
sprint/power events, in neither copy of their ACTN3
gene may have a natural predisposition to
sprint/power events. Knowing this information may
be helpful, not in eliminating choices for sport
activities but adding exposure to a host of team or
individual sport events.
Genetics (made simple)
Genetics (nucleus not the full story)
Inheritance
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Basic human traits are passed on
Can be single gene responsible but most
traits are complex interaction of multiple
genes and environment
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Height, weight
Diseases – heart disease, cancer, diabetes
Genetic stability and mutation
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Most genes remain same
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Many systems in place to reduce risk
mutation
Genes change or mutate creating
variation
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Harmful
Neutral
Beneficial
Genetic variation
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A-T-G-C “alphabet”
Every gene is a specific sequence
“when my brother came home he lied”
What is the genetic variation?
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Genetic mutation (Single Nucleotide Protein’s)
Alleles
Single gene disorder
Multifactorial gene disorder
Chromosomal disorder
Alleles
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Alternate forms of the same gene
0.1 percent difference in DNA accounts for all
human difference
Dominant allele
Recessive allele
Incomplete dominance
Mendel and genetics
Darwin and Evolution
Genotype:
Phenotype:
Dd or DD
Detached
dd only
Attached
d
d
D
d
Dd
dd
Dd
dd
D = detached (dom)
d = attached (recess)
Single gene disorder:
Autosomal vs Sex chromosome
what type of disorder?
what type of disorder?
Chromosomal disorder
Multifactorial disorder
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Most diseases
interaction of multiple genes
Interaction of genes and environment
Genetic testing
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Diagnostic tests
Carrier tests
Predictive tests
Diagnostic tests
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Confirms or excludes a diagnosis
Used when a person has signs or
symptoms of a disease
For example, dementia in a 35 year old
Carrier testing
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If family member has a disorder or is a
carrier
Individuals with increased risk due to ethnic
or racial group
Often offered as part of family planning
Predictive tests
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Pre-symptomatic
ie. Phenylketonuria screening
autosomal recessive condition
new born screening
amino acid phenylalanine
Predictive tests
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Pre-dispositional
ie BRCA ½, ACTN3
Increases risk but do not guarantee
disease
Family Health History
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U.S. Surgeon General’s Family History
Initiative
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Encourage patients to learn more about their
family health history
Thanksgiving Day is family health day
Family health history
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Inexpensive way to look at genetics
Not everything in a family health history is genetic…
Identify red flags
Family History- red flags
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Early onset of disease
Multiple affected individuals
Clustering of key diagnoses
One family member with multiple cancers
Presence of disease in people with healthy
habits more suggestive genetic cause
Remember that lack of family history doesn’t
rule out genetic cause!
Genetics in Primary Care Project
Genetics and Politics
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Human Genome Project
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Completed in 2003 - international consortium
Identify all the 20,000 to 25,000 genes in human DNA
Genes range from 2,000-2,000,000 base pairs
Only 2% of DNA
“Junk” DNA
Determine the sequence of the 3 billion chemical base pairs
Store information in databases
Improve tools for analysis
Transfer technology to private sector
Address ethical, legal and social issues
Limits & Pitfalls of Genetics Testing
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Breast cancer representative of typical
challenges related to testing for many
genetics disorders BRCA 1/2
Case: Breast Cancer
A 23 yo woman has a history of an aunt with breast cancer
and her mom just got diagnosed with breast cancer at
age 45.
Should she get genetic testing?
What are pros & cons of testing?
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Pros:
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Reduction in uncertainty and “not knowing”
Facilitation of informed decision-making re: options
to reduce risk
Knowledge obtained for relatives may be important
Testing may affect reproductive choices so
planning can be undertaken
What are pros & cons of testing?
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Cons:
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(+) BRCA indicates higher risk, but development of
cancer isn’t certain
(-) BRCA doesn’t ensure woman won’t develop
breast cancer
Risk-reducing interventions decrease but do not
eliminate risk
Some risk-reducing interventions are invasive and
carry significant medical and psychological
implications, for some including reproductive
choices
Cost, limits of insurance coverage
Broader implications?
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Cost
Privacy and discrimination
Eugenics
Balancing strengths and weaknesses
Genetic Information
Nondiscrimination Act (GINA)
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May 2008
Health insurers – prohibited from using
genetic test results to set premium or
requiring or using test results in any way
Employers – prohibited from obtaining or
using genetic test results in any way
For Monday:
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Complete your family history and
questions on Connect
Read Chapter 3: Mental health and
Stress