GATA2 mutations screening is recommended prior to ... - CBMTG

GATA2 mutations screeningis recommended prior to related transplantfor selected cases of young patient withmyelodysplastic syndromePécheux L., Teira P., Bittencourt H., Laramée L., Dormoy-Raclet V.,Duval M., Hébert J., Haddad E., Cellot S.

12-years-old boy with myelodysplastic syndrome (MDS)WBC: 1.77 x 10 9 /LNeutrophile: 0.7x10 9 /L (1.8-7.0)Lymphocyte: 0.7x10 9 /L (1.5-5.1)Monocyte: 0.1x10 9 /L (0,3-0.9)Hb: 105 g/L (VGM 114 fL)Platelet: 144 x 10 9 /LRecurrent viral infections, WartsNormal Bone Marrow (Giemsa, x100) Myelodysplastic syndrome (Giemsa, x100)

Abnormal Karyotype:47,XY,+1,der(1;7)(q10;p10),+8[17]/46,XY[4]

Asymptomatic lung infiltrateMycobacteriumFortuitum

Unusual MDS presentationXGATA2( )=> MonoMAC syndrome?(adapted from Dick et al.,Cell Stem Cell 2012)

Three hematopoietic GATA family membersare essentiels for lineage specificationGATA 2GATA 1GATA3

Several GATA2 mutations are describedin MDS/AML spectrumGATA2ZF1ZF2MutationsHot Spotin MonoMacSyndrome

MonoMAC syndrome: frequent familial incidenceGenotype: T354 (Thr354, Thr354)T354M (Thre354, Met354)(Adapted from Hahn et al., Nature Genetics 2011)

Diagnostic test design:=> GATA2 mutation c.1186 CT (R396W)ZF1ZF2GATA2Ex1 Ex2 Ex3 Ex4 Ex5 Ex6a Ex6bcoding sequence covered by the testC / TPatientFrèreCBrotherNegativecontrolC+ External validation at Laboratory of Dr Scott in Australia

Familial pedigreeColon cancer Bone cancer? AbdominalCancer?R396R396R396Wde novo GATA2 mutationWith MonoMAC SyndromeAnd MDSR396

Patient is in partial second remissionBUSULFAN14 mg/kg total(targeted concentration800 ng/ml)+CYCLOPHOSPHAMIDE200 mg/kg totalCYCLOSPORIN5mg/kg/d+RELAPSE+9mFLAG-Idare-inductionDLID+100D+100PartialremissionMETHOTREXATE15mg/m2 x1 then10mg/m2 x2 dosesAntibioticsAntibiotics

Characteristics of GATA2 mutationsLoss of Function« Silent » carriers?Impaired DNA binding capacity(Hahn et al., Nature Genetics 2011)GATA2 mutationsecond hit(Dickinson et al., Blood 2011)MDS-AML

Other important predisposing genesfor familial MDS/AMLRUNX1CEBPαRHD TADTAD1 TAD2 bZIPMutationsHot SpotMutationsHot Spot=> Familial Platelet DisorderSong et al., 1999=> Familial AMLSmith et al., 2004=> Loss of function=> Autosomal dominanttransmission=> Loss of function=> Autosomal dominanttransmission

HSCT is the only curative treatment• 8 cases of mutated-GATA2 patients and HSCT:– Only 2/8 related-donor HSCT– Usually very good outcome except for 2 cousins (withadditional ASXL1 acquired mutations)Cuellar-Rodrigues et al., Blood 2011Bodor et al., 2012• 6 cases with mutated-RUNX1 transplanted withcells from affected sibling donors had suboptimaloutcome– Slow, incomplete or failed engraftment(3)– Early relapse(1)for familial MDS/AML– EBV-lymphoproliferative disorders (2)Liew et al., 2011

CONCLUSIONS• Screening for GATA2-mutations should be done earlyin young MDS/AML patient and their related donors:‣ with monocytopenia or atypical mycobacterial infection‣ with familial history (in addition to RUNX1 and CEBPαscreening)• Access to molecular diagnostic laboratory in order toidentify theses patients• Bio-banking facilities for preservation of diagnosticsamples for subsequent analysis (blood, BM andsaliva)

AcknowledgementDr Sonia CellotLouise LaraméeBenjamin TurgeonVirginie Dormoy-RacletDr Sonia Cellot LaboratoryResearch CenterCHU Sainte-JustineDr Pierre TeiraDr Henrique BittencourtDr Michel DuvalDr Élie HaddadPediatric Hematology-Oncology& Pediatric ImmunologyCHU Sainte-JustineDr Josée HébertAmélie GiguèreBanque de Cellules Leucémiques du QuébecHôpital Maisonneuve-Rosemont

MDS with der(1;7)(q10;p10):is it different from MDS with -7/del(7q)?• In adults:– 1-3% of MDS– MDS with der(1;7) vs del(7q) ou -7:• Clinic and biology: differents• 5years overall survival: similar(Slovak et al., Cancer Genet Cytogenet. 2009)• In children:– 3/192 children with MDSin a recent review(Göhring et al., Blood 2010)– Pronostic?

SMD avec anomalies cytogénétiquesMonosomie 7q (64% des cellules)Trisomie 8 (84% des cellules)

GATA2 mutations have been recently describedwith different phenotypes associated with MDS/AML(Adapted from Hyde and Liu et al,Nature Genetics 2011(Adapted from Holme et al, BJH 2012)

MonoMAC syndrome: frequent familial incidence(Adapted from Bodor et al., Haematologica 2012)

Mutation GATA2 c.1186 CT (R396W)PatientYPatientFrèreBrotherNegativecontrol

GATA2 mutations leads to Loss of Function(Dickinson et al., Blood 2011)• Image localisaiton• Image perte defonction

What about silent carriers?Anticipation or waiting for the 2 nd hit?GATA2 mutationsecond hitMDS-AML

Loss of function or dominant negative?• Mice GATA2 m /GATA2 wt :defects in granulocytemacrophageprogenitorsRodrigues et al., Blood 2008• Somatic mutations reported in CML patients inblastic crisisZhang et al., Leuk. Res. 2009• High levels of GATA2 expression are associated withpoor prognosis in pediatric AMLLuesink et al., Blood, 2012Vincente et al., Crit. Rev. Oncol, Hematol, 2011

Functional consequences of GATA2 mutations (1/2)N terminal frameshift mutation=> premature terminations=> non-functional protein lacking most of the C-terminal?OrDifferent translation start or activation of an alternative translationproduct downstream of the mutated nucleic acid(cf GATA1 mutations => short form of GATA1 with dominantnegative activity)=> protein with different activity=> different phenotype

Functional consequences of GATA2 mutations (2/2)OrAlteration of DNA binding and interactions with cofactors like FOG-1 and PU-1Different mutations => different effect on binding capacity(Dickinson et al., Blood 2011)Enforced expression of GATA2 in myeloid progenitors induce down-regulation ofcrucial myeloid transcription factors PU.1 and CEBPA