private pay, physician ordered genetic testing developed by dr. judith allanson, ms. shawna morrison...

Private pay, physician ordered genetic testing

Developed by Dr. Judith Allanson, Ms. Shawna Morrison and Dr. June Carroll Last updated November 2015

Disclaimer

• This presentation is for educational purposes only and should not be used as a substitute for clinical judgement. GEC-KO aims to aid the practicing clinician by providing informed opinions regarding genetic services that have been developed in a rigorous and evidence-based manner. Physicians must use their own clinical judgement in addition to published articles and the information presented herein. GEC-KO assumes no responsibility or liability resulting from the use of information contained herein.

Objectives• Following this session the learner will be able to:– Refer to their local genetics centre and/or order genetic

testing appropriately regarding private, physician ordered genetic testing

– Discuss and address patient concerns regarding private, physician ordered genetic testing

– Find high quality genomics educational resources appropriate for primary care

Case 1: Julie and Chris

• Julie and Chris are a healthy non-consanguineous newlywed couple– Both are 33yo– Julie is of French Canadian and Northern European

ancestry– Chris is of German and English ancestry and he

believes there may be some Ashkenazi Jewish ancestry

Case 1: Julie and Chris• Julie and Chris are planning to start their family• Julie’s cousin, Jean, is the same age and also recently

married• Jean lives in Boston, MA• She was offered a family planning carrier screening

panel which was partly covered by her health insurance

• Julie would also like to have this panel and understands that she would have to self-pay and needs you to order the test

• She has brought all the completed paperwork to you

Case 1: Julie and Chris

What is ethnicity-based carrier screening in Canada?

What is ethnicity-based screening in Canada?

• Connect with your local genetics centre for more on your local population– E.g. French Canadian from Saguenay-Lac-Saint-Jean or

Charlevoix regions

What is ethnicity based screening in Canada?


• Self-pay expanded carrier screening is not standard of care and does not replace current screening guidelines

• Voluntary• Variable severity of conditions• Conditions have different modes of inheritance• Risk assessment based on accurate paternity• Negative screen does not eliminate risk• In some instances, test may be diagnostic or reveal

information about an individual’s personal health– E.g. adult-onset ‘Tay Sachs disease’, fragile X carrier, Ataxia-

Telangiectasia carriers

Pre-test counselling for expanded carrier screening

Pre-test considerations for expanded carrier screening

• You may choose not to screen for all available conditions. You may exclude testing for: – Disorders which usually present in adulthood and

genetic testing cannot distinguish between childhood or adult onset (e.g. 1-antitrypsin deficiency)

– Genes where variants have low/no clinical utility (e.g. MTHFR)

– Conditions where the most appropriate approach to screening is something other than molecular testing, often because of low penetrance (e.g. hereditary hemochromatosis)

Targeted mutation analysis is genetic testing for specific gene changes known to be pathogenic (also used for testing familial gene mutations)

Whole gene sequencing is genetic testing where all coding regions (exons) of the gene are sequenced and compared to a reference sequence. Variants in the genetic codes are classified as benign, pathogenic or variant of uncertain significance.

Targeted mutation analysis vs. Whole (exon) gene sequencing

Pre-test considerations



Potential Benefits:•Lower cost•No chance of variants of uncertain significance

Potential limitations:•Low detection rate* for many conditions, ethnicity dependant



Potential Benefits:•Higher detection rate (DR) across ethnicities

– On average detects about 94% of known clinically significant variants

– DR depends on coverage, i.e. how many times a gene region is read

Potential limitations:•Limited detection of some types of mutations e.g. insertions and deletions•Current recommendations are that laboratories report all variants that are pathogenic or ‘likely’ pathogenic

– How will you counsel for a variant?

– Will your local genetics clinic provide support?

• Genetic counselling through testing company may be available +/- extra fee

• You (ordering provider) should have a plan to provide accurate information and follow up to patients, including– Risk counselling and review of options– Test partner if one member of the couple is a carrier– Additional testing? Biochemical testing for non-Ashkenazi

Jewish (AJ) member of a couple where the AJ member is a carrier of Tay Sachs disease

– Significance of this information for other family members who may also be carriers

Post-test counselling for expanded carrier screening panel

Back to case 4: Julie and Chris• Julie and Chris are planning to start their family• Julie would like you to order expanded carrier

screening through a private genetic testing company• You agree to arrange for expanded carrier screening

and provide pre-test counselling• You, Julie and Chris select the conditions to be

screened for and agree to choose targeted mutation analysis versus sequencing

Back to case 4: Julie and Chris

• Julie and Chris are found to both be carriers of cystic fibrosis

• You refer the couple to your local genetics for follow-up counselling

• Pearls–Private pay, physician ordered genetic

testing supports patient autonomy and may help some couples avoid long wait times for genetics consults–Physicians ordering testing need to be

informed about the conditions on the panels and prepared to provide pre- and post-test counselling–Currently expanded carrier screening is not

standard of care

Resources

• See www.geneticseducation.ca for more details and how to connect to your local genetics centre

• To learn more about Canadian ethnicity-based carrier screening recommendations see the point of care tool

• For a recent article see Edwards JG, Feldman G, Goldberg J et al. Expanded carrier screening in reproductive medicine-points to consider: a joint statement of the American College of Medical Genetics and Genomics, American College of Obstetricians and Gynecologists, National Society of Genetic Counselors, Perinatal Quality Foundation, and Society for Maternal-Fetal Medicine. Obstet Gynecol 2015;125(3):653-62

private pay, physician ordered genetic testing developed by dr. judith allanson, ms. shawna morrison...

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