What did I inherit from my parents? 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? “Blue print” for your life Understand your potential health risk or predisposition Understand health strengths

Why is understanding of genetics important? Human Genome Project Increasing testing options 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 Basic human traits are passed on Can be single gene responsible but most traits are complex interaction of multiple genes and environment Height, weight Diseases – heart disease, cancer, diabetes

Genetic stability and mutation Most genes remain same Many systems in place to reduce risk mutation Genes change or mutate creating variation Harmful Neutral Beneficial

Genetic variation A-T-G-C “alphabet” Every gene is a specific sequence “when my brother came home he lied”

What is the genetic variation? Genetic mutation (Single Nucleotide Protein’s) Alleles Single gene disorder Multifactorial gene disorder Chromosomal disorder

Alleles 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: Dd or DD dd only Phenotype: Detached Attached

Dd dd Dd dd d D d d D = detached (dom) d = attached (recess)

Single gene disorder: Autosomal vs Sex chromosome

what type of disorder?

Chromosomal disorder

Multifactorial disorder Most diseases interaction of multiple genes Interaction of genes and environment

Genetic testing Diagnostic tests Carrier tests Predictive tests

Diagnostic tests 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 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 Pre-symptomatic ie. Phenylketonuria screening autosomal recessive condition new born screening amino acid phenylalanine

Predictive tests Pre-dispositional ie BRCA ½, ACTN3 Increases risk but do not guarantee disease

Family Health History U.S. Surgeon General’s Family History Initiative Encourage patients to learn more about their family health history Thanksgiving Day is family health day

Family health history Inexpensive way to look at genetics Not everything in a family health history is genetic… Identify red flags

Family History- red flags 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 Human Genome Project Completed in 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 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? Pros: 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? Cons: (+) 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? Cost Privacy and discrimination Eugenics Balancing strengths and weaknesses

Genetic Information Nondiscrimination Act (GINA) 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: Complete your family history and questions on Connect Read Chapter 3: Mental health and Stress