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The Primary Care Physician: The Primary Source of Genetic Testing Information Copyright University of Washington 2007

The Primary Care Physician: The Primary Source of Genetic Testing Information Copyright University of Washington 2007

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The Primary Care Physician:The Primary Source

of Genetic Testing Information

Copyright University of Washington 2007

Imagine this…

Dr. Step is wrapping up the summer camp physical for his 10 year-old patient, Jay. He has addressed Jay’s

Warts Emerging myopia Safety counseling

Time is up.

Jay’s mother, Lisa, stands up to leave and says, “By the way, my husband, Tim, has just been diagnosed with colon cancer, and his doctors are calling it familial adenomatous polyposis. I heard there is a genetic test for FAP. Should Jay be tested?”

Genetic Counseling

• What is FAP and what causes it?

• Who else in the family could get FAP?

• Should we be tested for FAP?

• How can we cope with FAP?

• What kind of genetic test is it?

• How would the genetic test be used?

• Where can I find a lab that does the test?

• What is involved in ordering this genetic test?

• How can I answer all the questions that the

family has?

Genetic Testing

Where is Lisa going to go for an answer?

71% of American adults say they would most

likely ask their primary care physician about a

genetic disorder present in their family.

Genetic Testing: A study of consumer attitude AMA March 1998

Where is Dr. Step going to gofor answers?

A text book? Out of date

A journal? Highly focused

A colleague? Expertise varies

A Web site?

www.genetests.org

FUNDED BYNational Institutes of HealthContract No. N01-LM-3503

SPONSORING INSTITUTIONUniversity of WashingtonSeattle, WA

GeneReviews

• Genetic disease descriptions• >380 Reviews (April 2007)• One new Review added each week

• Expert-authored, peer-reviewed

• Current information on genetic test use in diagnosis, management, genetic counseling

• Links to genomic databases, patient resources, PubMed citations, policy statements/guidelines

International Laboratory Directory

615 Clinical and research laboratories 1370 Inherited diseases

• 1080 clinical tests• ~290 research only

Genetics and prenatal diagnosis clinics

• United States: ~ 1000 clinics

• International: ~ 100 clinics

Educational Materials

• Genetic counseling and testing concepts

• PowerPoint slide show presentations on genetic testing resources

• Illustrated Glossary of >220 terms

• Links to GeneticTools, a curriculum for teachers of primary care physicians

What is FAP and what causes it?

Who else in the family could get FAP?

Should we be tested for FAP?

How can we cope with FAP?

Genetic Counseling

FAP

Summary

Diagnosis

Clinical Description

Differential Diagnosis

Management

Genetic Counseling

Molecular Genetics

Resources

References

ACP-Associated Polyposis Conditions

Summary

Disease description• Colon cancer syndrome• Polyps develop 7-36 years• Colon cancer at 34-43 years

Diagnosis/testing

• Caused by mutations in APC• 95% of patients have identifiable APC mutations

Genetic counseling• Autosomal dominant

Clinical Description

• Colorectal adenomatous polyps: average 16 years

• Colon cancer: average 39 years

• Other features: osteomas, dental abnormalities, desmoid tumors

• Extra-colonic cancers (small bowel, stomach, pancreas thyroid, CNS, liver, bile ducts)

ACP-Associated Polyposis Conditions

What is FAP and what causes it?

Who else in the family could get FAP?

Should we be tested for FAP?

How can we cope with FAP?

Genetic Counseling

Genetic Counseling

Mode of Inheritance

• Autosomal dominant

Risk to Family Members

Parents of a proband.

• 75-80% of probands have an affected parent • 20-25% have a de novo mutation

Sibs of a proband. • If a parent has FAP, risk is 50% • If neither parent has FAP, risk is low

Offspring of a proband.

• 50% risk

ACP-Associated Polyposis Conditions

What is FAP and what causes it?

Who else in the family could get FAP?

Should we be tested for FAP?

How can we cope with FAP?

Genetic Counseling

Genetic Testing

What kind of genetic test is it? How would the genetic test be used? Where can I find a lab that does the test? What is involved in ordering this genetic test? How can I answer all the questions that the

family has?

Cytogenetic

DNA

Metabolic

Types of Genetic Tests

Test Method Mutation Detection Rate Test Availability

Sequence analysis up to 90%

Mutation scanning and protein truncation ~80-~90% Clinicaltesting (PTT)

Protein truncation ~80%testing (PTT)

Duplication/deletion ~8-12%analysis

Molecular Genetic Testing

Direct DNA tests

Linkage

If no mutation is detected, linkage testing can be considered in families with more than one affected member.

ACP-Associated Polyposis Conditions

mutation scanning

de novo mutation

Genetic Testing

What kind of genetic test is it? How would the genetic test be used? How is the genetic test applied in this situation? What is involved in ordering this genetic test? How can I answer all the questions that the family has?

Diagnostic

Predictive

Carrier

Prenatal

Screening

Uses of Genetic Testing

FAP50% risk

10 y

39 y

Jay

LisaTim

Uses of Genetic Testing

Diagnostic

Predictive

Carrier

Prenatal

Screening

Management

Molecular genetic testing: By age 10-12 years

Surveillance: Persons with an APC mutation or at-risk for FAP who have not undergone molecular genetic testing:

• Annual sigmoidoscopy beginning at age 10-12 years

Colectomy: When polyps appear

ACP-Associated Polyposis Conditions

Management

Surveillance: Family members who have not inherited the disease-causing mutation:

• Routine colon cancer screening beginning at age 50 years

ACP-Associated Polyposis Conditions

Testing Strategy

Test Tim

Mutation detected• Direct testing useful• Proceed with testing family

• Direct testing not useful • Do not proceed with testing family

No mutation detected STOP

Genetic Testing

What kind of genetic test is it? How would the genetic test be used? Where can I find a lab that does the test? What is involved in ordering this genetic test? How can I answer all the questions that the

family has?

FAP

Hierarchical Search Result

Genetic Testing

What kind of genetic test is it? How would the genetic test be used? Where can I find a lab that does the test? What is involved in ordering this genetic test? How can I answer all the questions that the

family has?

Ordering Genetic Testing

Genetic tests may be ordered by any physician.

• Choosing a laboratory• Pretest counseling and informed consent• Sample logistics and supporting documentation• Test result interpretation and follow-up

Genetic Testing

What kind of genetic test is it? How would the genetic test be used? Where can I find a lab that does the test? What is involved in ordering this genetic test? How can I answer all the questions that

the family has?

FAPJay10 y

39 y 33 y 28 y

d. 35 y MVA

63 y

Indeterminant risk

50% risk

Amy6 y

Sarah14 y

Tim Lisa

Genetics Consultation

A genetics consultation involves care of an individual or family to: Providing or arranging for psychosocial support

• Confirm, diagnose or rule out a genetic condition

• Identify / arrange for medical management

• Calculate and communicate genetic risks

• Provide or arrange psychosocial support

Medical Geneticists (MD, PhD)Certified by: American Board of Medical Genetics

Genetic Counselors (MS)Certified by: American Board of Genetic Counseling

and/or American Board of Medical Genetics

Genetics Professionals

Testing Strategy

Test Tim

Mutation detected• Direct testing useful• Proceed with

• genetic counseling• genetic testing of all at-risk relatives• surveillance of mutation-positive relatives only

Testing Strategy

Test Tim

• Direct testing not useful • Proceed with

No mutation detected STOP

• genetic counseling• surveillance of all at-risk relatives

FAPJay10 y

39 y 33 y 28 y

d. 35 y MVA

63 y

Indeterminant risk

Amy6 y

Sarah14 y

50% risk

Tim Lisa

AK MI TX

CA TN

Clinic Search Result

What is FAP and what causes it?

Who else in the family could get FAP?

Should we be tested for FAP?

How can we cope with FAP?

Genetic Counseling

Genetics Professional Patient

Primary Care Provider

Genetic Counseling and Testing

Roberta A Pagon, MD

Thomas D Bird, MD Cynthia R Dolan, MS Gerald L Feldman, MD, PhDRichard JH Smith, MD, PhDKaren Stephens, PhD

Suzanne B Cassidy, MDMary Beth P Dinulos, MD

Monica Smersh

Miriam Espeseth, MA

Carla Gifford

Editor-in-Chief

Associate Editors

Assistant Editors

Managing Editor

Online ProductionEditor

Editorial Assistant

Genetic Counselors

Laboratory DirectoryCoordinator

Clinic Directory Coordinator

Cynthia R Dolan, MSRoberta Spiro, MA

Gina McCullough Grohs

Aliya Hashemi

Database Administrator

SystemsAdministrator

Sergey Mikhaylov, MS

Brad Willson

Staff

GeneReviews

Principal Investigator Roberta A Pagon, MD

Directories

Technical Support

Resources

Resources Liaison Kathi Marymee, MS