genetics 101: demysifying genetics
TRANSCRIPT
“Genetics 101” Demystifying Genetics
Kathleen Calzone, PhD, RN, APNG, FAANNational Cancer Institute, Center for Cancer Research, Genetics Branch
DNA Book
What is a Gene?Physical unit of inheritanceAre passed from parents to offspringContain information needed to specify traits
Genes are arranged on structures called chromosomes
Chromosomes contain a single long DNA molecule of which only a portion corresponds to a single gene
Humans have approximately 20,000 genes
Autosomal Dominant Inheritance
Each child has 50% chance of inheriting the mutation
No “skipped generations”
Equally transmitted by men and women
https://ghr.nlm.nih.gov/handbook/illustrations/patterns?show=autodominant
Autosomal Recessive Inheritance
Two germline mutations (one from each parent) to develop disease
Equally transmitted by men and women
https://ghr.nlm.nih.gov/handbook/illustrations/autorecessive
X-Linked
Mutant genes are on the X (sex) chromosome Women inherit 2 mutated copies to be affected Men who inherit the mutation are affected (only one X
chromosome)https://ghr.nlm.nih.gov/handbook/illustrations/xlinkrecessive
Definitions
Genetics – study of individual genes and their impact on relatively rare single gene disorders
Genomics – study of all the genes in the human genome together, including their interactions with each other, the environment, and other psychosocial and cultural factors
Cancer Arises From Loss of Normal Growth Control
Cancer cell division
Fourth orlater variantn
Third variant
Second variant
First variant
Uncontrolled growth
Cell Suicide or Apoptosis
Cell damage—no repair
Normal cell division
Germline (Inherited)/Somatic (Acquired)
EpigeneticsActivation and deactivation of genes without any change in the underlying DNA sequence of the organism
• Chemical compounds that modify genome function
• Are not part of the DNA itself
Preconception/Prenatal
Newborn Screening
Risk Identification
Screening/DiagnosisDisease
Characterization
IndividualizedTherapy
Management At End of Life
After EndOf Life
Genetic and Genomic Influences Across the Healthcare Continuum
Inte
rdis
cipl
inar
y C
olla
bora
tion
to Im
prov
e P
atie
nt O
utco
mes
Calzone, et al. (2013). Relevance of genomics to healthcare and nursing practice. Journal of Nursing Scholarship. 45, 1-2.
Scope of Genomic InformationSources of genomic material
Blood, tumor, saliva, cheek swab •Stability of DNA•Testing can be performed on stored specimens
Family historyFeatures of a disease or disorder Family genetic test results
Obligate carrier
Obligate Carrier
http://www.genome.gov/27541954
• Begin colonoscopy at age 40
• Avoid high fat in diet
• Genetic defect targeted therapy for specific disease
• Drug dose of medication determined by drug metabolism genetic profile
Risk prediction Pharmacogenomics New Therapies
The Precision Medicine Initiative
DefinitionDisease treatment and prevention that incorporates individual genetic variation, environment and lifestyle
Overarching AimTo accelerate the pace of moving precision medicine into every day clinical practice.http://www.nih.gov/precisionmedicine/https://www.whitehouse.gov/precision-medicine
The Precision Medicine InitiativeExpand efforts in cancer genomics
Support trials testing combinations of targeted therapies based on tumor’s molecular signature
Develop solutions to drug resistance
Develop approaches assessing response to therapy
Develop new tumor cell models to predict response to drug combinations and define mechanisms of resistance
The Precision Medicine Initiative, cont
Long Term GoalsEstablish a research participant group of >1 million Americans who will share data, biologic samples, diet/lifestyle information, and linked to their Electronic Health Record if they choose.
Emphasis on engaged participants
Institute of Medicine Roundtable on Health Literacy
March 2, 2016-Health Literacy and Precision Medicine: An Important Partnership
Mission-inform, inspire, and activate a wide variety of stakeholders to support the development, implementation, and sharing of evidence-based health literacy practices and policies
http://iom.nationalacademies.org/Activities/PublicHealth/HealthLiteracy.aspx
Resources to Learn More
Talking Glossary http://www.genome.gov/Glossary
http://unlockinglifescode.org/
Next 3 Destinations: Unlocking Life's Code Exhibition Traveling ScheduleDiscovery World Milwaukee, Milwaukee, WI
January 18 - April 25, 2016Natural History Museum of Utah, Salt Lake City, Utah
May 21 - September 5, 2016Exploration Place, Wichita, KS
September 30 - January 1, 2017
