1 BRCA1 and BRCA2 genetic testing

24 Pages·2015·1.43 MB·English

reviews
AnnalsofOncology
AnnalsofOncology26:2057–2065,2015
doi:10.1093/annonc/mdv278
Publishedonline7July2015
BRCA1 BRCA2 —
and genetic testing pitfalls
and recommendations for managing variants
fi
of uncertain clinical signi cance
† †
D.M.Eccles1, ,G.Mitchell2,3, ,A.N.A.Monteiro4,R.Schmutzler5,F.J.Couch6,A.B.Spurdle7
‡ D
&E.B.Gómez-García8*,onbehalfoftheENIGMAClinicalWorkingGroup o
w
n
1FacultyofMedicineAcademicUnitofCancerSciences,SouthamptonGeneralHospital,Southampton,UK;2FamilialCancerCentre,PeterMacCallumCancerCentre,The lo
a
UniversityofMelbourne,Melbourne,Australia;3HereditaryCancerProgram,DepartmentofMedicalOncology,UniversityofBritishColumbia,Vancouver,Canada;4Cancer de
EMpoidleecmuliaorloMgeydPicroingeraCmo,loHg.nLee(eCMMoMffiCtt),CUannicveerrsCiteynHteors,pTitaamlCpoa,loUgSnAe,;C5Coelongtnere,foGreHrmeraendyit;a6ryDBepreaartsmtaenndtoOfvLaarbiaonraCtoarnycMere,dCiecninteerafnodrIPnatethgoralotegdy,OMnacyooloCglyin(iCc,IOR)oacnhdesCteern,tUerSfAo;r d fro
m
7MolecularCancerEpidemiologyLaboratory,DivisionofGeneticsandComputationalBiology,QIMRBerghoferMedicalResearchInstitute,BNE,Herston,Australia; h
8DepartmentofClinicalGenetics,MaastrichtUniversityMedicalCentre,Maastricht,TheNetherlands ttp
s
://a
c
a
Received8December2014;revised5February2015and21April2015;accepted8June2015 d
e
m
ic
.o
u
p
Background:IncreasinguseofBRCA1/2testingfortailoringcancertreatmentandextensionoftestingtotumourtissue .c
o
m
for somatic mutation is moving BRCA1/2 mutation screening from a primarily prevention arena delivered byspecialist /a
geneticservicesintomainstreamoncologypractice.Aconsiderablenumberofgenetestswillidentifyrarevariantswhere nn
o
clinicalsignificancecannotbeinferredfromsequenceinformationalone.Theproportionofvariantsofuncertainclinical n
c
significance (VUS) is likely to grow with lower thresholds for testing and laboratory providers with less experience of /artic
BRCA.MostVUSwillnotbeassociatedwithahighriskofcancerbutamisinterpretedVUShasthepotentialtoleadto le
mismanagementofboththepatientandtheirrelatives. -ab
s
Design:MembersoftheClinicalWorkingGroupofENIGMA(Evidence-basedNetworkfortheInterpretationofGermline tra
c
MutantAlleles)globalconsortium(www.enigmaconsortium.org)observedwidevariationinpracticesinreporting,disclos- t/2
6
ureandclinicalmanagementofpatientswithaVUS.Examplesfromcurrentclinicalpracticearepresentedanddiscussed /1
0
to illustrate potential pitfalls, explore factors contributing to misinterpretation, and propose approaches to improving /2
0
clarity. 5
7
Resultsandconclusion:Clinicians,patientsandtheirrelativeswouldallbenefitfromanimprovedlevelofgeneticliter- /14
4
acy.Geneticlaboratoriesworkingwithclinicalgeneticistsneedtoagreeonaclinicallyclearanduniformformatforreport- 0
2
4
ingBRCAtestresultstonon-geneticists.Aninternationalconsortiumofexperts,collectingandintegratingallavailable b
linesofevidenceandclassifyingvariantsaccordingtoaninternationallyrecognizedsystem,willfacilitatereclassificationof y g
u
variantsforclinicaluse. e
s
Keywords:variantsofuncertainsignificance,VUS,BRCA,clinicalutility,classification t o
n
2
0
N
o
v
e
m
introduction ‘deleterious variants’ in BRCA genetic testing parlance and the b
e
term pathogenic variant is used here for the sake of precision. r 2
Germline inactivating variants in the tumour suppressor genes Pathogenicvariantsineithergeneconferahighlifetimeriskof 01
8
BRCA1 and BRCA2 confer high lifetime risks of breast cancer,
developingovarianor(another)primarybreastcancerinfemale
ovariancancerandlessfrequentlyalsoothercancers[1].These carriersbuttheyexplainonly∼20%offamilialbreastcancer[2].
pathogenic variants are conventionally called ‘mutations’ or
The more cancers, the younger the onset and the admixture
of ovarian with breast cancer among relatives all increase the
chance that a familial cluster is due to a BRCA gene mutation
*Correspondenceto:DrEncarnaB.Gómez-García,DepartmentofClinicalGenetics,
but, nonetheless, most familial clusters of breast cancerare not
Maastricht University Medical Centre, P. Debyelaan 25, 6202 AZ Maastricht,
The Netherlands. Tel: [phone]; Fax: [phone]; E-mail: Encarna. duetoaninheritedmutationinBRCA1orBRCA2.Inaddition
[email protected] to familial clusters, BRCA mutations account for over 10% of
patients with early onset triple-negative breast cancer and over
†Theseauthorsarejointfirstauthors.
‡ENIGMACWGcontributors:seeAppendix. 10% of women with non-mucinous ovarian cancer unselected
©TheAuthor2015.PublishedbyOxfordUniversityPressonbehalfoftheEuropeanSocietyforMedicalOncology.
Allrightsreserved.Forpermissions,pleaseemail:[email protected].
reviews
AnnalsofOncology
for family history [3, 4]. Female carriers with pathogenic var- canbeclearlyclassified.Differentlinesofevidence mayappear
iants can make informed decisions about prophylactic surgery to conflict, so an integrated estimation of probability taking all
orintensifiedscreeningprogrammes.High-profilemediacover- available evidence into account is essential to reach a final
age increases patient expectations from genetic testing [5, 6]. classificationformanyvariants[20,21].
The indications for germline genetic testing for BRCA1 and
BRCA2 are further increasing to include directing cancer multiple lines of evidence may be required to establish
chemotherapy,noveltargetedtreatmentsandinformingchoices pathogenicity. Software packages are available to help interpret
abouttheextentoftherapeuticsurgery[7–9].Germlinegenetic genetic variants, each with strengths and weaknesses (Table 2).
testing for BRCA1 and BRCA2 for cancer risk prediction and UnderstandingofhowthemultiplefunctionsoftheBRCA1and
management is routinely delivered by clinical genetics profes- BRCA2proteinsrelatetocancerpredispositionislimitedandfew
sionals but increasing demand is overwhelming the current validated functional assays are available [22]. The interpretation
delivery model with insufficient capacity among trained geneti- offunctionalstudiesisoftentechnicallycomplex,andresultsmay D
o
cists and genetic counsellor. Safe integration of genetic counsel- not be calibrated against clinical parameters in order to give w
lingandtestingtoidentifyHereditaryBreastandOvarianCancer measuresof sensitivityand specificity. A major breakthroughin nlo
a
inmainstreamoncologyisanongoingchallenge.Challengesexist thefieldofBRCAvariantclassificationhasbeenthedevelopment d
e
at many levels but key are genetic literacy and genetic test out- of a multifactorial likelihood classification model [20, 23]. It is d fro
comeinterpretationandreporting. anticipated that functional data from BRCA1 and BRCA2 will m
Variability between individuals’ genetic code is common soonbeincorporatedinthismodel[22,24,25]. http
withinthegeneralpopulationandbetweenindividualsofdiffer- Themultifactoriallikelihoodmethodusesanumberofdifferent s
ent ethnic background, and this intrinsic variability can lead to independent features in order to establish acombined likelihood ://a
c
difficulties in interpreting some types of sequence change (see estimate that a BRCA variant has the characteristics of known ad
e
Figure 1 for more information). Variants of uncertain clinical pathogenicvariants[15].Themodelcurrentlycombinestheprior m
significance(VUS)representaparticularchallengesincetheclin- probabilityofvariantpathogenicity(basedonevolutionaryconser- ic.o
u
ical significance cannot be inferred from sequence information vationandaminoacidphysicochemicalproperties)withadditional p.c
alone. Misinterpretation of VUS can lead to real clinical harms estimatesofpathogenicityfromlikelihoodsbasedonclinicalinfor- om
forbothpatientsandfamilies[10–12].Furthermore,termsused mation,includingvariantco-occurrencewithaknownpathogenic /a
n
n
in genetic test clinical reports vary (see Table 1). Up to 20% of mutation in the same gene, tracking of the variant with cancer- o
n
BRCA1/2testswillreportgeneticVUSbut,inawell-characterized affectedfamilymembers(segregation)andBRCAtumourfeatures. c/a
ethnic population, the proportion may drop to 5% or less Theconceptunderlyingmultiparametricmethodsisthatempiric rtic
[13–15]. The Evidence-based Network for the Interpretation probabilitiesthataperson‘does’haveor‘doesnot’haveapatho- le-a
ofGermlineMutantAlleles(ENIGMA)consortiumhasreceived genic BRCAvariant can be established for each available line of b
s
over6000submissionsofunique VUS,identifiedinover13000 evidence[20].Multiplelinesofevidencecanbefactoredtogether tra
c
families from over 17 countries [16]. Laboratories following astheybecomeavailableinaniterativemannertoproduceanin- t/2
generic reporting rules and with limited BRCA-specific experi- creasinglyaccurateprobabilityofpathogenicityestimatesforanin- 6/1
0
encemayresultinreportswithmorecategoricconclusionsabout dividual variant. These estimates can be used to classify variants /2
0
variantsinBRCAgenesthanissupportedwhenmultiplelinesof intoclinicallyrelevantstrata(Table3)[18]. 57
evidencearetakenintoaccount[17].Thepercentageofgenetests /14
resultinginaVUSisexpectedtoincreasewhentheextentofse- several classification systems havebeen proposed and there is no 40
2
quencing increases to include untranslated and deeper intronic international consensus on which to adopt. A universal system 4 b
regionsandwhentumourtestingisoffered.Werestrictexamples for classification of variants common across all countries would y g
u
inthispapertotheBRCAgenestestedinbloodsamples. facilitateeducationamongnewusersofgenetictestsandminimize e
s
Members of the ENIGMA consortium’s Clinical Working theriskofmisinterpretation.Unfortunately,multiplesystemshave t o
n
Grouphavecollatedrealcasescenariosfromclinicalpracticetoil- been proposed and are currently in use with many reporting 2
lustratethepitfallsthatcanariseafteraVUStestresultandsuggest laboratoriesnotofferingaclinicallyrelevantclassification.AWorld 0 N
o
somestrategiestomitigatethisrisk.Clinicianswhoarerequesting HealthOrganization-fundedexpertworkshopattheInternational v
e
BRCA tests need to consider these issues when using BRCA test Agency for Research on Cancer (IARC) in 2008 recommended m
b
e
resultsinthemanagementofpatientsandtheirfamilies. that the score from a multifactorial likelihood model is used to r 2
categorize high-risk cancer gene variants [26] based on the 0
1
8
multifactorial likelihood estimates of variant pathogenicity [18].
theVUSreport:whyareVUSdifficulttoclassify? This is the only published classification system that links clinical
pitfalls associated with variability in the information content of recommendationsto each class (Table 3). The American College
genetic test reports. Based on the experience of representatives of Medical Genetics are recommending ClinVar as a common
from 17 countries, it is clear that there is currently no repositoryforgeneticvariantstohelpstandardisereportinginthe
internationally accepted standard for BRCA testing reporting UnitedStates(Table4).
(Table 1), and no agreed consistent classification system: some
laboratories report variants without interpretation, some use a databases reporting genetic variants. A number of web-based
narrativeapproachandsomeuselocallydevelopedguidelinesor resourcescataloguevariantsreportedintheBRCA1and2genes
published schemes [18, 19]. For some types of BRCA gene (Table4).Forallvariantdatabases,ongoingcurationofdeposited
variants, additional evidence may be essential before a variant information, both at the time of deposition and reclassification,
| Ecclesetal. Volume26 |No.10| October2015
reviews
AnnalsofOncology
Variation in DNA is common
Facts and terms Further information
When a gene is tested for mutations, the The human genome contains ~ 6 billion bases of genetic
sequence of that gene in the individual is sequence in any diploid cell and on average there is a change
compared to an accepted reference in the reference sequence approximately every 500 bases,
sequence for the gene and variation from much of this variation does not obviously impact on function
the reference sequence is often observed. but occasionally it does.
BRCA1 and BRCA2 are very large genes Random variation in the reference sequence occurs frequently
across the population, not associated with any clinical effect.
This is true whether the individual has had cancer or not.
Non-pathogenic variation in sequence It is tempting to believe that because a person with cancer has
is as frequent in the general population been tested for a mutation in the BRCA1/2 gene, that any D
as in the cancer affected patient deviation from the expected code is causative but in reality, in o
w
the absence of clear evidence of a loss of function in the n
lo
mutated copy of the gene, most of the genetic variation is of a
d
little or no significance in relation to disease causation e
d
Different ethnic groups have different For ethnic populations where relatively little genetic testing has fro
m
frequencies of variants been undertaken, common polymorphisms in that ethnic h
minority group may be unrecognised in the testing laboratory ttp
asingdn iafircea nthceer e(VfoUreS )m. ore likely to be reported as of uncertain s://a
c
a
Terms used in describing genetic variants de
m
Polymorphisms (meaning “many When observed frequently in population controls (unaffected ic
.o
forms”) are common variations by cancer), this type of sequence change is generally not u
p
observed in more than 1% of the associated with a high cancer risk. .c
normal population. om
/a
A change in a single base (T,G,A or C) is Single nucleotide variants usually have no major clinical n
n
a single nucleotide variant and if the consequence especially if frequent (i.e. SNPs) but rarely they o
n
particular variant is relatively may affect the function of the protein being coded. c
/a
fproepquuleantitolyn ,o ibt sise rcvaellde din a a s pinagrtliecular Snoy ncohnaynmgeo utos: tah es ienxgplee cbtaesde a cmhiannog aec iind tahte t heaxto pno wsihtiiocnh sreos iuslts in rticle
nucleotide polymorphism (SNP) usually of no consequence but can create or destroy a native -a
b
donor or acceptor splice site. s
Non-synonymous: also known as missense mutations lead to a trac
change in one amino acid, these may affect a critical functional t/2
6
domain, although most do not. /1
0
Variants within an intron (ie non coding part of the gene) can /2
also rarely destroy or create false donor or acceptor splice sites. 05
7
In-frame deletions or insertions An insertion or deletion of three bases starting with the first /14
4
base of an amino acid code is an in frame deletion or insertion 0
2
and leads to the insertion or deletion of one or sometimes more 4
amino acids but the full length protein is otherwise predicted to by
be complete. These may have no effect on protein function since gu
most of the protein is translated correctly. es
t o
Variants of uncertain significance (VUS) Where a change to the expected sequence is observed that has n
2
not been observed with any frequency in the testing laboratory 0
and has not been classed as non-pathogenic in literature or N
o
databases, genetic testing laboratories will usually report these ve
as a VUS. Gathering multiple lines of additional information may m
b
help to clarify pathogenicity [15]. In reality most of these are e
unlikely to be pathogenic mutations but a few will be. r 20
1
8
Figure1. Geneticvariabilityinformation.
is a significant challenge. Some databases are actively curated mandated so databases cannot usually be used to derive
while others rely heavily on the classification by the submitting population frequencies of variants to aid classification (e.g.
laboratory with varying levels ofsupportingdataprovided. Also laboratories tend to under-report variantsthat have been found
importantistheuseofstandardizedHGVSnomenclature(http:// several times) and many do not catalogue the supporting
www.hgvs.org/)allowingunambiguouscomparisonofalldataon evidence used to determine pathogenicity. A new attempt to
thesamevariantinthedatabaseandacrosstheliterature.Apart collate BRCA VUS for the purpose of classification is the
from occasional national consortia, reporting of variants is not PROMPT registry (www.promptstudy.org). Patients receiving a
Volume26| No.10| October2015 doi:10.1093/annonc/mdv278 | 
reviews
AnnalsofOncology
Table1. TypesofsequencevariantsreportedinBRCAmutationdetectiontestsaccordingtoriskrelevantforclinicalmanagement
Clinical Descriptorsobservedinclinical Interpretation
risk reports
High Functionallydeleteriousmutation Variantsthatresultinahighlifetimeriskofbreastandovariancancer.Deleteriousvariantsdisrupt
Pathogenicmutation normalproteinfunction.Theyincludenonsensechanges,out-of-frameinsertionsordeletions,
High-riskmutation largegenerearrangementsorsplicingvariantsalteringthecanonicalsplicingacceptoranddonor
Deleteriousvariant sitesdisruptingregulatoryregions,aswellassomemissensechanges.Supportiveevidencefrom
multiplesourcesmayberequiredtocallavariantdeleteriouswherepredictionsoffunctional
consequencesareuncleara.
Uncertain Missensemutation VariantsthatdifferfromthepublishedreferenceDNAsequence(RefSeqBRCA1:U14680;BRCA2:
Rarevariant NM00059)andarenotclassifiableaseitherdeleteriousorasneutralbasedonavailableevidence.
Variantofuncertainclinical Theassociationwith‘clinicalphenotype’atthistimeis‘unknown’andcannotbeusedtoinform Do
w
significance(VUS,VOUS) clinicaldecisions. n
lo
Uncertainvariant a
d
Variantofuncertain ed
Variantofunknownclinical fro
m
significance
h
None Frequentmutation ChangesintheDNAsequencethatdonotdisruptthenormalfunctionoftheencodedproteinand ttp
s
Commonvariant arenotassociatedwithaclinicallyimportantincreasedriskofdisease.Ifpresentinthe ://a
Polymorphism populationatafrequencyof>1%,thesemaybereferredtoaspolymorphisms. c
a
Variantsoflowclinicalsignificance de
m
Variantsofnoclinicalsignificance ic
Neutralvariants .o
u
Benignvariants p.c
o
m
aForexampleassaysshowingpartiallossofnormaltranscriptfromaberrantsplicingorpartiallyreducedfunctionfromanaminoacidsubstitutionmay /a
n
requireadditionalevidencetoclassifyasclass4or5. no
n
c
/a
rtic
BRCAVUSresultareinformedabouttheregistrydirectlybythe insufficientevidenceofpathogenicity.Inthisscenario,additional le-a
collaborating testing laboratory (including Myriad and Ambry evidencefromsegregationanalysesisessentialtoallowamultifac- bs
Genetics) and/ortheirclinician.The patient can submita range torial estimation of the likelihood of pathogenicity before confi- tra
c
ofmedicalinformation,genetictestreportandtumourpathology dentlyusingthevariantinclinicalpredictivetesting. t/2
6
reports and opt to participate in a variety of variant-specific /1
0
researchstudies. pitfalls derived from frequency and population of origin of the /2
0
5
VUS. Rare variants (allele frequency <0.01) are usually not 7
Case1:Twofamilieswereidentifiedinseparatecountrieswith classifiable by an individual laboratory due to paucity of /14
4
the same missense variant in BRCA1 designated c.5212G>A, informationandlackofstatisticalpower.Whentheethnicityof 02
NM_007294.3 (p.Gly1738Arg). A number of women in both the patient being tested differs from the patient groups where 4 b
y
families were seeking risk-reducing surgery because of a strong most testing has been done, a sequence variant may have little g
u
familyhistoryofearlyageofonsetofbreastcancerintheirfam- publicallyavailabledataandberareinthatlaboratorysoismore e
s
ilies.The variant was aclass 3 (uncertain) variant (Table 3) but likelytobeconsideredaVUS. t o
n
it occurred at a highly conserved residue, and it was recognized 2
0
that more evidence may successfully confirm it was pathogenic. Case 2: A 35-year-old woman of African ancestry developed N
o
Predictivetestingcouldthenbeofferedtoat-riskfamilymembers two primary breast tumours presenting at age 25 and 33. Both v
e
tofacilitatetheirpreventivechoices.Eachfamilyprovidedinsuffi- tumours were estrogen receptor negative (ER-), progesterone m
b
e
cientpowerforaninformativesegregationanalysisbutcollabor- receptornegative(PR-)andhumanepidermalgrowthfactorre- r 2
ation across centres in two countries with the same variant, ceptor2negative(HER2-).Shehadnofamilyhistoryofcancer, 0
1
8
allowed a segregation analysis to be completed and the VUS but testing was initiated on the basis of her personal cancer
couldthenbere-classifiedasclass5(definitelypathogenic)[27]. history. She was found to have two VUS in BRCA1; variant 1,
It took a fortuitous academic collaboration and over 3 years to c.5154G>T, NM_007294.3 (p.Trp1718Cys) and variant 2 in
re-classify this VUS. Unless the phenotypes and genotypes are the 30 UTR region, c.*36C>G, NM_007294.3. DNA samples
depositedinafreelyaccessibledatabase,thensuchavariantwill from relatives indicated that both variants are likely located on
remainclass3.TheENIGMAconsortium[16]providesamech- thesameallele.Variant2isfrequent (6%–11%)intheAfrican-
anismtorapidlylinkclinicalteamslookingafterfamilieswiththe American population [28] and could be assigned to class 1
same VUS to pool evidence. Since BRCA germline mutations (non-pathogenic).Variant1involvesaminoacidsubstitutionat
explain only a minority of all cases presenting with breast or ahighlyconservedresiduepredictedinsilicotohaveafunction-
ovarian cancer, two unrelated patients with these relatively alimpactbutcould notbeclassifiedunambiguously duetoin-
common phenotypes and the same rare BRCA1 variant provide sufficient data. The clinical dilemma for this patient thus
| Ecclesetal. Volume26 |No.10| October2015
reviews
AnnalsofOncology
Table2. Examplesofsoftwaretoolsavailableforclinicalvariantevaluationonline
Resource Description Website
Polyphen2 POLYmorphismPHENotypes http://genetics.bwh.harvard.edu/pph2/
Polyphen2isfreelyavailable,web-basedprogramfromHarvardUniversitythat
predictswhetheranaminoacidsubstitutionaffectsproteinstructureand
function.
SIFT SortingIntolerantFromTolerant http://sift.jcvi.org/
SIFTsoftwareisfreelyavailableandpredictswhetheranaminoacidsubstitution
affectsproteinfunction.
Align-GVGD AlignGranthamVariationandGranthamDeviation. http://agvgd.iarc.fr/about.php
Align-GVGDisafreelyavailable,web-basedprogramfromInternationalAgency
D
forCancerResearch(IARC)thatcombinestheknownchemicalnatureofamino o
w
acidsandthealignmentsofDNAsequencesacrossspeciestopredictthelikely n
lo
pathogenicityofmissensesubstitutions. a
d
HCIdatabaseofprior TheHuntsmanCancerInstituteDatabaseofPriorProbabilitiesofPathogenicityfor http://priors.hci.utah.edu/PRIORS/ ed
probabilities single-nucleotidesubstitutionsprovidesthepriorprobabilityofpathogenicity fro
m
estimatewhichisthestartingpointforthemultifactoriallikelihoodestimatefora
h
novelSNPidentifiedthroughgenetictestingforaBRCAgene. ttp
s
GeneSplicer GeneSplicerisafreelyavailableflexiblesystemfordetectingsplicesitesinthe http://www.ncbi.nlm.nih.gov/pmc/ ://a
genomicDNAofvariouseukaryotes. articles/PMC29713/ c
a
HumanSplicing Thistoolisfreelyavailableandaimedatstudyingpre-mRNAsplicingand http://www.umd.be/HSF3/ de
m
Finder identifyingvariantsthatmaydisruptnormalsplicing. ic
Commercialsoftware, Alamutiscommerciallyavailablesoftwarethatprovidesasingleinterfacetobring http://www.interactivebiosoftware.com/ .o
u
e.g.Alamut togethermultipledatasourcesincludingmanyofthoselistedaboveina software/alamut/overview p.c
simplifiedandstreamlinedtoolforrapidassemblyofdataaboutanyonevariant om
aimedatbusydiagnosticlaboratories. /a
n
Entrez-Pubmed Web-basedsearchenginestolookforresearchpublicationsincludingaspecific http://www.ncbi.nlm.nih.gov/pubmed no
n
GoogleScholar mutation. http://scholar.google.com c
/a
UMD-BRCA1 TheUMD-BRCA1/BRCA2databaseshavebeensetupinajoinednationaleffort http://www.umd.be/BRCA1/ rtic
UMD-BRCA2 throughthenetworkofthe16Frenchdiagnosticlaboratories.Aclassificationis http://www.umd.be/BRCA2/ le
proposedbasedontheclassicalparametersincludingsplicingalgorithms. -ab
s
Astrongeffortisdonetoperformco-segregationstudies. tra
c
t/2
6
Table3. 5-tierclassificationBRCA1/2VUSmodifiedfromref.[15] /10
/2
Class Description Probabilityofbeing Clinicalpredictive Management Researchtestingoffamily 05
7
pathogenic testingofatrisk recommendationsifat-risk members /1
4
relatives relativehasthevariant 4
0
2
5 Definitelypathogenic >0.99 Yes Fullhigh-riskguidelines Notindicated 4 b
4 Likelypathogenic 0.95–0.99 Yes Fullhigh-riskguidelines Maybehelpfultofurther y g
classifyvariant ue
3 Uncertain 0.05–0.949 No Presenceofvariantis Maybehelpfultofurther st o
irrelevanttorisk classifyvariant n 2
assessment,managerisk 0 N
basedonfamilyhistory o
v
e
only m
2 Likelynotpathogenicorofno 0.001–0.049 No Manageriskbasedonfamily Maybehelpfultofurther be
clinicalsignificance historyonly classifyvariant r 2
0
1 Notpathogenicorofnoclinical <0.001 No Manageriskbasedonfamily Notindicated 18
significance historyonly
becomes whether the available information about variant 1 is cancerat age 28 (grade III, ER−) and 30 (grade II, ER−, PR−,
sufficient to predict a high risk of ovarian cancer and recom- HER2–);Asturianproband2developedbreastcanceratage40
mendrisk-reducingbilateralsalpingo-oophorectomy(BSO). (ER and grade unknown), and probably also ovarian cancer at
A literature search identified two reports of variant 1. The age 63. The second report of the variant was in an African-
first report was of two families from Asturias, Northern Spain American patient and family members where the variant was
[29]. Contact with the authors clarified the following details, present in 4/4 women with cancer and absent in 3/3 at-risk
some directly applicable for variant interpretation: Asturian women without cancer. Pathogenicity was supported by the
proband 1 was diagnosed with bilateral invasive ductal breast functionalassayshowinglossoftranscriptionalactivity[30].
Volume26| No.10| October2015 doi:10.1093/annonc/mdv278 | 
reviews
AnnalsofOncology
Table4. CommonlyusedonlinedatabaseresourcesthatprovidesomeinterpretationofBRCAsequencevariantsalthough
Resource Description Website
IARC/LOVD[LeidenOpen SeparateBRCA1andBRCA2variantdatabasescuratedbyexpertsattheUniversity http://brca.iarc.fr/LOVD/home.
(source)VariationDatabase] ofLeidenandIARC.IncludesonlythoseVUSwithliteraturereferencesand php
recordsthepublishedliteratureassociatedwhicheachvariant.Eachvariantis soontobereplacedby
givenanIARCclass[15]andlinkstopublishedsourcedata.Submissionsof http://hci-exlovd.hci.utah.
variantsarefromregisteredsubmitterslargelyfromtheresearchcommunity. edu/home.php
Curationofsubmissionsforeachgeneisundertakenbyanamedexpertcurator
onavoluntarybasis.
TheBreastCancerInformation AdatabasethatactsasacentralrepositoryforBRCA1andBRCA2variants https://research.nhgri.nih.gov/
Core(BIC) (deleterious,neutralorVUS)depositedbysubmittersfromresearchandclinical projects/bic
D
sitesinternationally.Recently,acentralcurationprocessworkingtoclassifyall o
w
variantsaccordingtotheIARC5-tierclassification[15]schemehasbeen n
lo
introduced. a
d
ClinVar ClinVarisafreelyaccessible,publicarchiveofreportsoftherelationshipsbetween http://www.ncbi.nlm.nih.gov/ ed
humanvariationsandphenotypespresentedwithsupportingevidenceandan clinvar/ fro
m
indicationoflikelyclinicalsignificance.Submissionsarefromresearchandsome
h
diagnosticlaboratoriesandsubmittersincludeaclassificationforsubmitted ttp
s
variants,submissionsarenotcurrentlycurated. ://a
HumanVariomeProject TheHumanVariomeProject,undertheauspicesofUNESCO,hasbeencreatedas http://www. c
a
aunifiedreportingportalandlistsfourseparatedatabasesforBRCA1andfour humanvariomeproject.org de
m
forBRCA2.Asyetitoffersnoformalcurationorattempttoclassifyvariants. ic
.o
u
p
.c
o
m
Using multifactorial likelihood analysis [23] combining all reducing surgery. Additional information from a BRCA2 func- /a
n
currentlyavailableevidence:apriorprobabilityof0.81basedon tional assay was subsequently used to reclassify this variant to n
o
Align-GVGD prediction [31], and likelihood ratios based on class 2 (likely of no clinical significance) [33]. Cancer risk esti- nc
additional information gained about breast tumour pathology mates for the daughter and sister should have been based on /artic
[32],theposteriorprobabilityofpathogenicityforthevariantis familyhistoryalone.Sincetherewasnofamilyhistory,testingin le
0.98which places itin class 4. Thus, sufficient evidence is now relatives could not even provide useful additional information -ab
s
available to estimate a substantially raised ovarian cancer risk about segregation. It is worth noting here that the majority of tra
and permit a clinically sound recommendation of BSO to red- breast and ovarian cancer patients who will be offered germline ct/2
uceovariancancerrisk. BRCA testing to guide cancer treatment will not have a family 6
/1
historyofcanceramenabletosegregationstudies. 0/2
whyisgeneticcounsellingaroundVUScomplex? Thiscaseillustratestheneedtoensureimprovedgeneticliter- 05
7
Althoughitisexpectedthatmostclass3variantswillrepresent acyamongnon-geneticsprofessionalsorderingDNAtests,par- /14
ticularly the uncertainty around VUS results, the implications 4
non-pathogenicvariants,itiscriticalthatweimproveandaccel- 0
2
erateclinicalannotationandclassification. of testing in other family members and the need for a clear 4 b
pathway for referral to colleagues experienced in the interpret- y
g
ation and follow-up of variant results [34]. Many patients will u
limited genetic literacy among clinical professionals. Disclosure e
of a VUS result can test the skills of even highly experienced readily assume that any reported variant must be pathogenic st o
unlessthepotentialforaVUShasbeenclearlyflaggedaspartof n
geneticcounsellingteams.Therecanbeconsiderablevariationin 2
experiencewithmoleculargeneticsandwithclinicalBRCAgene thepre-testdiscussion. 0 N
o
testingleadingtodiverseclinicalmanagementrecommendations. ve
m
This situation is compounded by complex and variable perceptions of cancer risks associated with VUS. A genetic test b
e
presentation of diagnostic reports from laboratories and limited fora disease like breast cancer that uncovers a rare variant may r 2
geneticliteracyamongtreatingclinicians,andexacerbatedfurther leadtobothpatientsandclinicianstothink,‘whatisthechance 01
bythepatient’sperception,priorexperiencesandbeliefs. thisrarevarianthasnothingtodowiththisclinicalpresentation?’ 8
andconvincethemselvesitcannotbecoincidental.Thedecision
Case3:ABRCA2missensevariantp.Thr3033Ile(c.9098C>T, toundertakepreventivesurgeryiscomplexandpatientsarelikely
NM_000059.3) was identified in a 53-year-old woman with to have had personal and family experiences which may have
ovariancancerandnofamilyhistoryofbreastorovariancancer. strongly contributed to their risk management decision. Class 3
Aclass3reportwasissuedaslittlesupportingevidencewasavail- VUS reports discussed with counselees are too frequently
able.Themanagingcliniciantreatedthevariantasclinicallysig- inaccurately perceived typically leading to overestimation of
nificant and offered genetic testing to the patient’s daughter cancer risks, adverse psychological outcomes and more radical
and sister. The patient’s sister did not carry the variant, but the medical decisions [35, 36]. Furthermore, ‘almost the same large
daughterdid.Thedaughterwasgiventhesamecancerriskman- number of counselees with an unclassified variant decided to
agement advice as a pathogenic variant carrier including risk- havepreventivesurgeryaspathogenicmutationcarriers’[37].
| Ecclesetal. Volume26 |No.10| October2015
reviews
AnnalsofOncology
Patient meets criteria for genetic testing agreed with clinical
genetics service provider
P
a
Information about genetic testing discussed with oncologist tie
Patient gives informed consent to test and agrees timeframe for result nt o
ffe
BRCA testing re
d
g
e
n
e
tic
BRCA test BRCA test BRCA test s a
=no mutation found =VUS =pathogenic mutation p
p D
oin ow
tm n
e lo
n a
Recpaoncrcote nrres guveiletanwneettidc sby t if pre ded fro
fe m
FH-ve *FH+ve rs h
ttp
s
://a
Clinical genetics appointment c
a
d
e
* Family history meets local guidelines for referral to the m
No change to cancer pathway clinical genetic specialist service ic.o
u
p
Figure2. Suggestedmodelofaclinicalpathwayforbreastandovariancancerpatients.Initialgenetictestingthroughanoncologistwithbasictraining,expert- .co
m
iseroutinelycontributedbytheclinicalgeneticsconsultant.Thismodelworkswherethereisacloseworkingrelationshipbetweenoncologistandgeneticist /a
througharegularmultidisciplinaryteammeeting. nn
o
n
c
/a
Case 4: A BRCA1 VUS was identified some years previously probability of finding a pathogenic variant, the most likely rtic
inawomanwhodevelopedbreastcancerattheageof45inthe outcomefromtestingwouldbenopathogenicvariantfound,the le-a
setting of a strong family history of early onset breast and secondmostlikelyoutcomewouldbeaVUS,andtheleastlikely b
s
ovariancancer.Thefamilyunderstoodthatthevariantmustbe outcomeapathogenicvariant.Itisgoodpracticebeforeembark- tra
c
theanswertothestrongfamilyhistorydespitetheinconclusive ingonaBRCAgenetesttodiscusswiththepatientthelikelihood t/2
6
evidence. Several family members came forward for predictive ofthesepossibleoutcomes.Thetestresultmustbeinterpretedin /1
0
genetic testing which they incorrectly believed was available. the context of the family history and clear guidelines should be /2
0
Genetic testing was repeated some years later and a clearly agreedforreferralofcasestoaspecialistgeneticclinic(Figure2). 57
pathogenic large exonic deletion in BRCA1 wasthen identified Finally,theexperiencegatheredwithVUSinBRCA1/2isrelevant /14
on the opposite allele confirming irrefutably that the original todevelopingethicalnormsandpolicyissues,includingdutyto 40
2
VUS could not be pathogenic and demonstrating that new or re-contact patients, as cancer gene panel, exome and genome 4 b
y
optimized mutation screening approaches will uncover missed sequencingbecomeincreasinglycommonplace[38]. g
u
mutationsinsomefamilies. e
s
Thiscaseillustratestheimportanceofunderstandinga‘non- recommendations t o
informative’ or inconclusive test aimed at detecting a genetic n 2
0
predispositiontocancer.Itisimportanttobeawarethatmuta- We believe that some essential elements are necessary for the N
o
tion testing is <100% sensitive and a negative BRCA test result optimal clinical use and interpretation of VUS in mainstream v
e
does not exclude an underlying hereditary cause. BRCA1 or medicalpractice. m
b
BRCA2genemutationsonlyaccountforanestimated20%–30% er 2
offamilialclusteringofbreastcancer,socancerpatientsnegative variantreportingandclassification 01
8
foraBRCAtest,butwithastrongfamilyhistory,shouldbere- (cid:129) Aninternationallyacceptedterminologyandaclinicallyrele-
ferred for specialist assessment and advice about risk manage- vantclassificationtoreportanddiscussBRCAtestresults.
mentinthecancergeneticsclinic. (cid:129) A framework for clinicians, clinical scientists and research
The testing clinician has a responsibility to ensure that they groupstoworktogethertowardsclassificationofVUS.
have received appropriate training about the genetic testing
process and understand the possible outcomes and have appro- Reporting of sequence variants to a single, transparently and
priateexpertsupportfromageneticspecialist.Ahelpfulstarting expertlycurateddatabaseprovidingclinicallyrelevantclassifica-
point is to be able to estimate the probability of a deleterious tion for each reported BRCA variant based on clearly stated
BRCAmutationgiventhefamilyhistoryandtumourcharacteris- lines of evidence and freelyavailable to all providers of genetic
tic[38].Testingcliniciansshouldbeabletoexplainthelikelyout- testing. To submit variants to ENIGMA, go to contacts page
comesofthetesttotheirpatients;inpatientswithalowapriori http://www.enigmaconsortium.org/
Volume26| No.10| October2015 doi:10.1093/annonc/mdv278 | 
reviews
AnnalsofOncology
riskcommunication 7. AlsopK,FeredayS,MeldrumCetal.BRCAmutationfrequencyandpatternsof
(cid:129) Improve the genetics literacy of medical providers by struc- treatment response in BRCA mutation-positive women with ovarian cancer: a
reportfromtheAustralianOvarianCancerStudyGroup.JClinOncol2012;30:
tured training and integrating genomics into undergraduate, 2654–2663.
basicandspecialistmedicaltrainingcurriculae.
8. Tutt A, Robson M, Garber JE et al. Oral poly(ADP-ribose) polymerase inhibitor
(cid:129) Accessandclearreferralguidelinestospecialistclinicalgenet- olaparibinpatientswithBRCA1orBRCA2mutationsandadvancedbreastcancer:
icsservicesforpatientswithapathogenicvariant,aVUSora aproof-of-concepttrial.Lancet2010;376:235–244.
strongfamilyhistoryandnodetectablegeneticcause. 9. SchwartzMD,LermanC,BroganBetal.ImpactofBRCA1/BRCA2counselingand
(cid:129) Acloseworkingrelationshipbetweengeneticdiagnosticlabora- testing on newly diagnosed breast cancer patients. J Clin Oncol 2004; 22:
1823–1829.
tories, genetic specialists and cancer clinicians delivering an
10. Vadaparampil ST, Scherr CL, Cragun D, Malo TL, Pal T. Pre-test genetic
integratedcarepathwayforpatientsandtheirfamilies.
counseling services for hereditary breast and ovarian cancer delivered by non-
geneticsprofessionalsinthestateofFlorida.ClinGenet2014;87:473–477.
D
datareview 11. Pal T, Cragun D, Lewis C et al. A statewide survey of practitioners to assess o
w
(cid:129) Astandardoperatingprocedurewithinreportinglaboratoriesto kGneonwetleTdegsetManodlBciloinmicaarlkeprrsac2t0ic1e3s;r1e7ga:r3d6in7g–3h7er5e.ditarybreastandovariancancer. nloa
reviewvariantclassificationeachtimenewevidenceemerges. 12. Wideroff L, Vadaparampil ST, Greene MH et al. Hereditary breast/ovarian and de
(cid:129) (Alacbloeraartloyraiegsr)eeadndprroe-cceossntfaocrtirnegpoprattiinegntusp(dclaitneidciaclnass)siififcaatVioUnSs cMoelodreGcetnaeltc2a0nc0e5r;4ge2n:e7t4ic9s–k7n5o5w.ledge in a national sample of USphysicians. J d from
nbeocno-mpaetshocglaesnsiicfi.ed into clinically actionable or definitively 13. Cevhaelnueatviioxn-TroefncBhRCGA,1HaenadleyBRSC,A2LakDhNaAnisSequeetnacle. vGaerniaenttics oafndunhkinsotowpnathcolilnoigcaicl https
significance.CancerRes2006;66:2019–2027. ://a
c
14. Eggington JM, Bowles KR, Moyes K et al. A comprehensive laboratory-based a
d
concludingremarks programforclassificationofvariantsofuncertainsignificanceinhereditarycancer em
genes.ClinGenet2014;86:229–237. ic
.o
VUS identified in BRCA genes represent a major clinical chal- 15. LindorNM,GuidugliL,WangXetal.Areviewofamultifactorialprobability-based u
p
lenge. Individuals with significant family history, a pathogenic (mVUodSe).lHfourmclMasustiafitc2a0tio1n2;o3f3B:R8C–A211.andBRCA2variantsofuncertainsignificance .com
vsearrviaicnet.PoartiaenVtsUwSithshnooupldathboegerenfiecrrveadriatnotaorgaeVneUtiScsshpoeuclidalbiset 16. SthpeurindtleerpArBe,taHtioenaleoyfgSe,rDmelivneeremauutAanettalalel.leEsN:IaGnMiAn—terneavitdioennaclei-nbitaiasteivdenteotwevoarkluafoter /anno
managedbasedonthefamilyhistoryonly.Standardizedreport- risk and clinical significance associated with sequence variation in BRCA1 and nc
iinngtroadnudcebegtteenretgicesneitnictolitmeraaicnystmreaumst boencimolopgleym. eInntecdontoclussaifoenly, 17. BSpRuCrAd2legAenBe,sW.HhuilmeyMPuJt,atT2ho0m12p;s3on3:B2–e7t.al. BRCA1 R1699Q variant displaying /article
concertedactionbetweentheclinicalandresearchcommunities ambiguousfunctionalabrogationconfersintermediatebreastandovariancancer -a
b
misatxhiembuemst appatpireonatcbhentoefiotp.tTimhealilnytmernanataigoinnaglBERNCIGAMvaAriacnotnssoforr- 18. rrPeislockon.mJSmEM,eeEndcdcGalteeiosnneDstM2fo0,r1Ei2ams;pt4or9nov:Di5ng2e5tt–hale5.3Sin2et.qerupernectaetivoanrioafntccalnacsesrifiscuasticoenpatinbdilitryepgoerntientgic: stract/2
tiumisfocussedonimprovingtheinterpretationofBRCAVUS 6
testresults.HumMutat2008;29:1282–1291. /1
andincorporatesbothclinicalandresearchexpertise.Througha 0
collaborative approach and a global and unified source of data 19. BMRoCgAha1daasnidS,BHRoCflAa2ndaNs,seWssomutesntJNofetinal.sVilaicroianatsnaolyfsuisncearntdainasigpnroifipcoasnaclefoinr /205
and variant classification, important advances in this complex communicationingeneticcounselling.JMedGenet2013;50:74–79. 7/1
fieldwillcontinuetobenefitpatients. 20. Goldgar DE, Easton DF, Deffenbaugh AM et al. Integrated evaluation of DNA 440
sequence variants of unknown clinical significance: application to BRCA1 and 24
discloure BRCA2.AmJHumGenet2004;75:535–544. by
21. WalkerLC,WhileyPJ,CouchFJetal.Detectionofsplicingaberrationscausedby gu
Theauthorshavedeclarednoconflictsofinterest. BRCA1 and BRCA2 sequence variants encoding missense substitutions: es
implicationsforpredictionofpathogenicity.HumMutat2010;31:E1484–E1505. t o
n
references 22. MillotGA,CarvalhoMA,CaputoSMetal.AguideforfunctionalanalysisofBRCA1 20
variantsofuncertainsignificance.HumMutat2012;33:1526–1537. N
o
1. MavaddatN,PeockS,FrostDetal.CancerrisksforBRCA1andBRCA2mutation 23. Goldgar DE, Easton DF, Byrnes GB et al. Genetic evidence and integration of v
e
carriers:resultsfromprospectiveanalysisofEMBRACE.JNatlCancerInst2013; variousdatasourcesforclassifyinguncertainvariantsintoasinglemodel.Hum m
b
105:812–822. Mutat2008;29:1265–1272. e
2. MavaddatN,AntoniouAC,EastonDF,Garcia-ClosasM.Geneticsusceptibilityto 24. GuidugliL,CarreiraA,CaputoSMetal.Functionalassaysforanalysisofvariants r 20
breastcancer.MolOncol2010;4:174–191. ofuncertainsignificanceinBRCA2.HumMutat2014;35:151–164. 18
3. RischHA,McLaughlinJR,ColeDEetal.Prevalenceandpenetranceofgermline 25. IversenESJr,CouchFJ,GoldgarDE,TavtigianSV,MonteiroAN.Acomputational
BRCA1andBRCA2mutationsinapopulationseriesof649womenwithovarian method to classify variants of uncertain significance using functional assay data
cancer.AmJHumGenet2001;68:700–710. with application to BRCA1. Cancer Epidemiol Biomarkers Prev 2011; 20:
4. Couch FJ, Hart SN, Sharma P et al. Inherited mutations in 17 breast cancer 1078–1088.
susceptibilitygenesamongalargetriple-negativebreastcancercohortunselected 26. TavtigianSV,GreenblattMS,GoldgarDEetal.Assessingpathogenicity:overview
forfamilyhistoryofbreastcancer.JClinOncol2014;33:304–311. ofresultsfromtheIARCUnclassifiedGeneticVariantsWorkingGroup.HumMutat
5. Evans DGR, Barwell J, Eccles DM et al. The Angelina Jolie effect: how high 2008;29:1261–1264.
celebrityprofilecanhaveamajorimpactonprovisionofcancerrelatedservices. 27. AnagnostopoulosT,PertesiM,KonstantopoulouIetal.G1738RisaBRCA1founder
BreastCancerRes2014;16:442–447. mutation in Greek breast/ovarian cancer patients: evaluation of its pathogenicity
6. JamesPA,MitchellG,BogwitzM,LindemanGJ.TheAngelinaJolieeffect.MedJ and inferences on its genealogical history. Breast Cancer Res Treat 2008; 110:
Aust2013;199:646. 377–385.
| Ecclesetal. Volume26 |No.10| October2015
reviews
AnnalsofOncology
28. Newman B, Mu H, Butler LM et al. Frequencyof breast cancerattributable to appendix
BRCA1 in a population-based series of American women. JAMA 1998; 279:
915–921. Name and affiliationsoftheENIGMACWG contributors: (ex-
29. BlayP,SantamariaI,PitiotASetal.MutationalanalysisofBRCA1andBRCA2in cluding those named in the authors’ list). R. Driessen: Familial
hereditarybreastandovariancancerfamiliesfromAsturias(NorthernSpain).BMC CancerCentre,PeterMacCallumCancerCentre,TheUniversity
Cancer2013;13:243. ofMelbourne,Melbourne,Australia.N.M.Lindor:Department
30. Mirkovic N, Marti-Renom MA, WeberBL, SaliA, Monteiro AN.Structure-based
ofHealthSciencesResearch,MayoClinic,Scottsdale,USA.M.J.
assessmentofmissensemutationsinhumanBRCA1:implicationsforbreastand
Blok: Department of Clinical Genetics, Maastricht University
ovariancancerpredisposition.CancerRes2004;64:3790–3797.
MedicalCentre,Maastricht,theNetherlands.P.Moller:Research
31. TavtigianSV,ByrnesGB,GoldgarDE,ThomasA.Classificationofraremissense
Group Inherited Cancer, Department of Medical Genetics,
substitutions, using risk surfaces, with genetic- and molecular-epidemiology
applications.HumMutat2008;29:1342–1354. University Hospital, Oslo, Norway. M. de la Hoya: Molecular
32. SpurdleAB,CouchFJ,ParsonsMTetal.Refinedhistopathologicalpredictorsof Oncology Laboratory, Hospital Clínico San Carlos (IdISSC),
D
BRCA1 and BRCA2 mutation status: a large-scale analysis of breast cancer Madrid, Spain. T. Pal: Cancer Epidemiology Program, H. Lee o
w
characteristicsfromtheBCAC,CIMBA,andENIGMAconsortia.BreastCancerRes Moffitt Cancer Center, Tampa, USA. S. Domchek: Basser n
lo
2014;16:3419. Research Center and Abramson Cancer Center University of ad
33. Guidugli L, Pankratz VS, Singh N et al. A classification model for BRCA2 DNA PennsylvaniaPhiladelphia,USA.K.Nathanson:BasserResearch ed
binding domain missense variants based on homology-directed repair activity. CenterandAbramsonCancerCenterUniversityofPennsylvania fro
CancerRes2013;73:265–275. m
34. LvainrdiaonrtsNoMf,uGncoeldrgtaairnDsiEg,niTfiacvatnigciea:naSpV,rimPleornfoSrEp,roCvoiudcehrsFtoJ.aBssRiCstA1in/2dissceuqsuseinocnes PGheinlaedtieclsp,hiLa,eidUeSnA.UCn.ivVerasnityAsMpeerdenic:alDeCpeanrttmere,ntLeoifdeCnl,initchael https
andinmedicalmanagement.Oncologist2013;18:518–524. Netherlands. O. Diez: Oncogenetics Group, University Hospital ://a
35. PetrucelliN,LazebnikN,HuelsmanKM,LazebnikRS.Clinicalinterpretationand Vall d’Hebron; Vall d’Hebron Institute of Oncology (VHIO), cad
recommendationsforpatientswithavariantofuncertainsignificanceinBRCA1or Barcelona, Spain. K. Rheim: Center for Hereditary Breast and em
BRCA2:asurveyofgeneticcounselingpractice.GenetTest2002;6:107–113. Ovarian Cancer, Center for Integrated Oncology (CIO) and ic.o
36. VosJ,Gomez-GarciaE,OosterwijkJCetal.Openingthepsychologicalblackbox Center for Molecular Medicine Cologne (CMMC), University up
ingeneticcounseling.ThepsychologicalimpactofDNAtestingispredictedbythe Hospital Cologne, Germany. D. Stoppa-Lyonnet: Genetics .co
counselees’ perception, the medical impact by thepathogenicor uninformative m
BRCA1/2-result.Psychooncology2012;21:29–42. Service, Curie Institute, University of Paris Descartes, Paris, /an
France.M.Parsons:MolecularCancerEpidemiologyLaboratory, n
3387.. B8GVo2Rosm2C–AJe8,1z-3/OG20t:at.errcneiacWaEl,lB,v,ainnAtmeArbCpereertgtaetaniol.nTT,,hBaenlocdkouiMmnJsp,ealcvletaenosn’devliniefewW.ioPjnfsgyaacnahroudonncAcl.aosPlosaigfitiyeedn2ts0va0wr8iait;nh1ta7inn: GMDe.endGeitcoiaclldsgaRanred:seDCaroecpmhaprtuImntasettniiottuntaoel,fBDBioNelroEmg,yatHDoleiovrgsistyio,onnH,,uQQnILtMsDmR,anBAeurCsgtahrnaoclfieearr. onc/article
unclassifiedgeneticvariantintheBRCA1orBRCA2genesshowdifferentclinical Institute, UniversityofUtah SchoolofMedicine; SaltLake City, -ab
featuresfromthosewithamutation.JClinOncol2005;23:2185–2190. Utah,USA. stra
c
t/2
6
/1
0
/2
0
5
7
/1
4
4
0
2
4
b
y
g
u
e
s
t o
n
2
0
N
o
v
e
m
b
e
r 2
0
1
8
Volume26| No.10| October2015 doi:10.1093/annonc/mdv278 | 