Transcript This presentation is for educational purposes only and - GEC-KO

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 nonconsanguineous 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?
What is ethnicity-based 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
Private pay, physician ordered
genetic testing
Private pay, physician ordered
genetic testing
• Self-pay expanded carrier screening is
not standard of care and does not
replace current screening guidelines
Pre-test counselling for expanded carrier
screening
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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, AtaxiaTelangiectasia carriers
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. a-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)
Pre-test considerations
Targeted mutation analysis vs. Whole (exon) gene sequencing
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.
Pre-test considerations
Targeted mutation analysis vs. Whole (exon) gene sequencing
Potential Benefits:
Potential limitations:
• Lower cost
• Low detection rate* for
many conditions,
• No chance of variants of
ethnicity dependant
uncertain significance
Pre-test considerations
Targeted mutation analysis vs. Whole (exon) gene sequencing
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?
Post-test counselling for expanded
carrier screening panel
• 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
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 medicinepoints 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