Magee Symposium March 8 slides.
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Transcript Magee Symposium March 8 slides.
I inherited What???
You and Your Genes:
The Explosive New World
of Genetics
Kara Levine, MS, LCGC
Genetic Counselor,
GeneDx Whole Exome Sequencing Program
Disclosure
In relation to this presentation, I declare
the following real or perceived conflicts
of interest:
I am employed by GeneDx, a commercial
genetic testing laboratory that performs
whole exome sequencing.
GeneDx is a wholly owned subsidiary of
BioReference Laboratories, a publicly
traded company.
Overview
Basics of Inheritance:
Dominant vs. Recessive Inheritance
Jewish Genetic Diseases (JGDs)
Genetic risks faced by Jewish individuals
Carrier Screening for and Prevention of JGDs
What is Carrier Screening?
Past, Present, and Future of Carrier Screening
Who Should Be Screened for Which Diseases
and When should it be done?
Options for carriers to have healthy children
Summary and Resources
Basics of Inheritance
Types of Inheritance
Autosomal Dominant
Autosomal Recessive
Sex-linked/Sex-limited
X-linked
Y-linked (Paternal)
Mitochondrial (Maternal)
Epigenetic (Imprinting)
Multifactorial - most diseases
Autosomal Dominant Inheritance
• 50% risk with each pregnancy
• Males and females are equally affected
• Often variable expression with reduced penetrance
Autosomal Recessive Inheritance
• Carriers are
healthy
• If both parents
are carriers…
• 25% risk with
each pregnancy
• Males and
females are
equally affected
Jewish Genetic
Diseases (JGDs)
What are Jewish Genetic Diseases?
Recessive conditions that have a higher
incidence among Ashkenazi Jews
Caused by founder effect
Founder Effect
19 Most Common JGDs*
Disorder
Bloom Syndrome
Canavan disease
Cystic Fibrosis
Dihydrolipiamide dehydrogenase
deficiency (LAD)
Familial Dysautonomia
Familial Hyperinsulinism
Fanconi Anemia (C)
Gaucher disease
Glycogen storage disease type 1a
Joubert syndrome
Maple syrup urine disease
Mucolipidosis IV
Nemaline myopathy
Niemann-Pick (A)
Spinal Muscular Atrophy
Tay-Sachs disease (DNA+enzyme)
Usher syndrome 1F
Usher syndrome 3
Walker-Warburg syndrome
Carrier frequency
1/100
1/40
1/25
1/96
1/30
1/66
1/89
1/15
1/71
1/92
1/81
1/122
1/149
1/90
1/41
1/25
1/141
1/107
1/112
Detection Rate
97%
98%
97%
95%
Residual Risk
1/3301
1/1951
1/801
1/1901
99%
88%
99%
95%
99%
>99%
99%
96%
99%
95%
90%
98%
75%
98%
>99%
1/2901
1/543
1/8801
1/281
1/7001
1/9101
1/8001
1/3026
1/14801
1/1781
1/401
1/1201
1/561
1/5301
1/11101
*Currently under evaluation for expansion of the panel
1 in 4
Ashkenazi Jews
is a carrier for
at least one of 19
preventable JGDs
Know Your Family History
Important to know your family history for all
genetic disease, not just JGDs (i.e. breast
cancer), and review it with a genetic counselor
Though autosomal recessive conditions are not
typically present in multiple generations, some
JGDs are common enough that it can happen
Example: Gaucher disease (GD)
AJ Carrier frequency: 1/15
Risk to baby (carrier status unknown):
1/15 * 1/15 * 1/4 = 1/900 = ~0.1%
Risk to baby if one grandparent has GD:
1 * 1/15 * 1/4 = 1/60 = ~1.7%
JGD Example: Tay-Sachs Disease
Carrier frequency in Ashkenazi Jews is ~10 times that
of the general population (1/25 vs 1/250)
Caused by deficiency of the lysosomal enzyme betahexosaminidase A (HEXA gene), which leads to a
buildup of toxic GM2 ganglioside in neurons
3 types: infantile, juvenile, &
adult onset
Progressive fatal genetic disorder
Initially healthy infants, with
regression before age 2, leading
to seizures, paralysis, blindness,
and death, often by age 5
Carrier Screening
What is Carrier Screening?
Examines a (typically) healthy individual’s
DNA for specific known genetic changes
(mutations) which can cause disease in
future children
Does not examine all genes or mutations
Not a diagnostic test or a risk assessment
for the individual being tested
Typically needs to be a blood test
Can be performed at any point in one’s
reproductive life, but best time is
preconception
Turn-around time is usually 4 to 8 weeks
Why Screen for JGDs?
High carrier frequency
High morbidity/mortality
Actionable!
Many options available to mutation
carriers
Cost of testing has come WAY down
Testing covered by most insurance
companies
Personalized Medicine/Standard of Care
History of JGD Screening
Blood Test for HexA enzyme levels to screen for
Tay-Sachs (TSD) carriers (1970s)
Led to a 90% reduction in the birth of babies with
TSD
Still the gold standard with highest detection rate
when combined with mutation analysis
American College of Obstetricians and
Gynecologists
4 Jewish genetic diseases in 2004
American College of Medical Genetics
10 Jewish genetic diseases in 2008
Victor Center
19 Jewish genetic diseases in 2014
JGD Screening Today
Number of diseases to screen changes rapidly at
this point as the cost of adding new
genes/mutations to these panels is nominal
Mt. Sinai is currently offering a JGD carrier
screening panel of 38 diseases
Pan-ethnic panels are also now available, and
screen for gene mutations that are common in
many ethnicities, including Ashkenazi Jewish
Genetic Information Non-Discrimination Act (GINA)
provides some protections for employment (with >15
employees) and health coverage since 2008
Does not protect against life insurance discrimination
Which JGDs to Screen?
Old Panel: 19 Genes
Newer Panels: 38+ Genes (Mt. Sinai)
Pan-ethnic Panels: >100 genes
Physicians don’t need to ask ethnicity
Best option for individuals
with mixed
ancestry or in interfaith relationships
Usually contain Sefardic Jewish Disorders
However, not all panels are created
equally…more later from Dr. Finegold
Who should be screened?
Ashkenazi Jewish adults of reproductive age
(18-45)
Jews of eastern or central European descent
Individuals with some Jewish heritage, even if only
1 Jewish grandparent
Individuals of unknown ancestry
When in doubt, screen!
Start with screening just one member of couple
if already pregnant, screen both simultaneously
Screen Jewish partner first if one partner is a
non-Jew; If Jewish partner is a carrier, also
screen/sequence the non-Jewish partner for
that disease
Who is an Ashkenazi Jew?
Jews of central/eastern European descent:
95% of the Jews in the United States
Russia, Belarus,
Ukraine, Moldova,
Estonia, Latvia,
Lithuania,
Germany, Poland,
Austria, Hungary,
Romania, Norway,
Sweden, Great
Britain, Ireland,
Northern Ireland,
France, Italy
When should you be screened?
PRE-CONCEPTION (annual GYN visit)
The IDEAL time to screen is BEFORE child-
bearing, so couples have all of their
reproductive options available to them
POST-CONCEPTION (1st OB visit)
If a woman is already pregnant and has not
been screened, both members of the couple
should be screened simultaneously
BEFORE EACH SUBSEQUENT PREGNANCY
Update carrier screening before each
pregnancy, as screening for new diseases may
become available
Where can you be screened?
Women: OB/GYN or PCP
Men: PCP
Magee-Womens Hospital of UPMC
MWH Center for Medical Genetics
(412) 641-4168 or (800) 454-8155
Allegheny Health Network
Allegheny Perinatal Associates
(412) 359-4186
JGenesPgh Screenings
Next local Screening: March 31st, 2-6pm at Hillel
Dor Yeshorim Program
for some orthodox communities
focus is prevention of stigmatization
Reproductive Options for Carriers
Prenatal diagnosis
Chorionic villus sampling (10-13 weeks)
Amniocentesis (After 15 weeks)
Decision to continue or terminate an affected
pregnancy
Sperm or egg donation
In Vitro Fertilization (IVF) with
Preimplantation Genetic Diagnosis (PGD)
Adoption
Future of JGD Screening
JGD panels continue to expand
Pan ethnic panels continue to expand
Future screening tests are likely to be NextGeneration Sequencing Panels or Whole
Exome Sequencing (WES)
This technology exists now
Prices have decreased substantially
Exome/Genome knowledge advances daily
Some individuals may ultimately choose these
options to look at their reproductive risks as
well as their own personal health risks (i.e. for
future disease/cancer)
Summary
JGDs are recessive genetic disorders that can affect
anyone, but children of Jewish individuals are at
higher risk
Carrier screening is available for 19+ disorders and
should be performed before pregnancy
(preconception) if possible
Carrier screening is recommended even for
individuals who have only ONE Jewish grandparent,
as well as interfaith couples
If an interfaith couple, the Jewish individual should be
screened first, even if that is the male partner
Screening should be updated before each
pregnancy since the screening panels are
continuously expanding
Online Resources
Coming Soon: www.JGenesPgh.org
YU’s Program for Jewish Genetic Health
Free online educational webinars, etc.
www.myjewishgenetichealth.com
Jewish Genetic Disease Consortium
http://www.jewishgeneticdiseases.org
Center for Jewish Genetics
https://www.jewishgenetics.org
Victor Center
www.victorcenters.org
www.youtube.com/watch?v=uVJflKVMqlg
CDC Office of Public Health Genomics
www.cdc.gov/genomics/implementation
Additional Resources
ACOG FAQ about “Preconception Carrier
Screening” for ALL ethnicities:
www.acog.org/~/media/For Patients/faq179.pdf
Gene Screen app
for your iPhone
Thank you!