Will your child be sick as well? Testing before pregnancy B. Gulbis, M.D., PhD Université Libre de Bruxelles Brussels, Belgium 6 th EUROPEAN SYMPOSIUM ON RARE ANAEMIAS 1 st Dutch-Belgian meeting for patients and health professionals 21 st - 22 nd November 2015 Amsterdam - The Netherlands
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This talk is applicable for: Thalassemia s Sickle cell disease Membrane disorders (e.g. sferocytosis) Enzym defects (e.g. PKD, G6PD) PNH Other forms of hemolytic disease Definite X X X X Probable
Plan Preconception prenatal diagnosis: the procedures Invasive Non-invasive Future? How to provide those diagnostic procedures? 4
Will our child be sick as well? Genetic counselling
Invasive procedures Prenatal diagnosis Prenatal diagnosis (Antenatal screening) 6
Invasive procedures Prenatal diagnosis Prenatal diagnosis (Antenatal screening) Amniocentesis Chorionic Villous Sampling Fetal Blood Sampling 7
Invasive procedures Prenatal diagnosis: 10 12 weeks Prenatal diagnosis (Antenatal screening) Amniocentesis Safety Ultrasound guidance Fetal medicine specialists Not before 10 weeks of gestation (see limb disruption defects) Post-procedure loss 1% Chorionic Villous Sampling For Prenatal Diagnosis (1983: Rodeck et al; Simonini et al; Ward et al). Fetal Blood Sampling 8
Invasive procedures Prenatal diagnosis: after 15 weeks Prenatal diagnosis (Antenatal screening) Amniocentesis Safety Ultrasound guidance Fetal medicine specialists Not before 15 weeks of gestation (see direct fetal injury, amniotic membrane damage, high rate of culture failure) Post-procedure loss 0.5% Chorionic Villous Sampling Fetal Blood Sampling 9
Hôpital Erasme experience CVS = 40% (107/268) Prenatal diagnosis 10
CVS - Amniocentesis CVS Amniocentesis Timing (weeks) 10 11 15 - Chance of successful sampling 99% (contamination) 99% Miscarriage risk ± 1% ± 0.5 % Time required for diagnosis 3 7 days 3 to 7 days Culture: 2 to 3 weeks 11
Preimplantation Genetic Diagnosis (PGD) In vitro fertilisation Diagnosis on day 4 Transfer on day 5 12
Preimplantation Genetic Diagnosis (PGD) PGD-PCR For monogenic diseases For HLA typing 13
Preimplantation Genetic Diagnosis (PGD) PGD for whom? Infertile couples Previous history of termination of pregnancy Objection to termination of pregnancy Thinking of a saviour baby 14
Preimplantation Genetic Diagnosis (PGD) PGD with HLA-typing 1/4 HLA matched embryos Risk of no transferable embryo Future of non-hla matched embryos but without the disease? 15
Preimplantation Genetic Diagnosis (PGD) Most frequent indications Number of cycles Cystic fibrosis (CF) Myotonic dystrophy (DM1) Huntington disease (HD) Haemoglobinopathies (HBB) Fragile-X syndrome (FraX) Spinal muscular atrophy (SMA) + HLA typing (HBB + HLA; HLA) DMD, Duchenne muscular dystrophy; NF1, neurofibromatosis type 1; HaemA, haemophilia A; HLA, human leukocyte antigen for acquired diseases; APC, familial adenomatous polyposis; CMT1, Charcot-Marie-Tooth disease type 1; FAP, familial amyloidotic polyneuropathy; MS, Marfan syndrome; TS, tuberous sclerosis; VHL, Von Hippel Lindau. The ESHRE PGD Consortium: 10 years of data collection Harper J et al. Hum. Reprod. Update 2012;humupd.dmr052 16
Preimplantation Genetic Diagnosis (PGD) Neonatal follow-up of 995 born children PGD= No extra risk Mean term Prematurity Mean birthweight Perinatal death Major malformations Neonatal hospitalizations Congenital anomalies Desmyttere S. et al Hum. Reprod. 2012; 27:288-93. 17
Preimplantation Genetic Diagnosis (PGD) Up to 4 attempts per family to achieve a suitable donor sibling ~20% embryos diagnosed as suitable for transfer ~10% embryos diagnosed as suitable for transfer if + HLA-typing 18
PGD experience Hôpital Erasme Fertility Clinic First PGD for haemoglobinopathy in 2006 Records treated: n= 70 64 for sickle cell disease (3 HbS thal.; 6 HbSC) 6 for thal. major Records rejected: 9/70 - without follow-up: 16/70 63 cycles for 29 couples (Mean 2.2 cycle by couple) PGD performed on 34 cycles (54%) all for SCD 19
PGD experience Hôpital Erasme PGD failure (biopsy not obtained): n= 29 cycles Failure of stimulation (not enough oocytes) 48% To few embryos 21% No fecundation 14% Low quality of the embryos 7% Spontaneous pregnancy 7% 20
PGD experience Hôpital Erasme Diagnosis on day 4: 151 embryos Unaffected, poor quality embryos Transfer not possible N= 20 (31%)? 11 Unaffected embryos N= 107 (71%) Unaffected, good quality embryos transferred N= 54 (50%) Affected embryos N= 33 Cryopreservation N= 20 (19%) 21
PGD experience Hôpital Erasme Diagnosis on day 4: n= 151 Transfer on day 5: n= 54 Pregnancies: n= 18/54 (33%) Failure: n= 10 16.5% Baby n= 9 (1 twins) 22
Prenatal/Preimplantation genetic diagnosis Prenatal diagnosis PGD Accuracy of genetic analysis 99% 99% Risks Miscarriage, fetal injury No greater risk than conventional procedures Major drawbacks Decision of abortion for affected embryos Technically challenging Risk of IVF Low pregnancy and birth rates Costly 23
From the technique to the patient Couples should be clearly counselled before embarking on this reproductive option Detection of couple at risk Genetic counselling Fertility team If failure of stimulation or no fecundation Molecular diagnosis If failure of pregnancy or transferable embryo If failure of HLA matching embryo 24
Other options? Non-invasive prenatal testing with cell-free DNA an accurate diagnosis of the presence or absence of the paternal mutation in the fetus was not possible in all cases to make it clinically applicable. D'Souza E et al J Postgrad Med. 2013 Jan-Mar;59(1):15-20. doi: 10.4103/0022-3859.109483. Detection of fetal mutations causing hemoglobinopathies by non-invasive prenatal diagnosis from maternal plasma. provided that a previously born child is available for testing to determine the linkage to the paternal SNPs. Phylipsen M Prenat Diagn. 2012 Jun;32(6):578-87. doi: 10.1002/pd.3864. Epub 2012 Apr 20. Non-invasive prenatal diagnosis of beta-thalassemia and sickle-cell disease using pyrophosphorolysisactivated polymerization and melting curve analysis. 25
Other options? Gene therapy Ongoing clinical trials 26
Other options? New regulators of foetal haemoglobin? two SNPs - BCL11A region rs4671393 and rs11886868 three SNPs - HBS1L-MYB region rs28384513, rs9399137 and rs4895441 Nguyen TK et al Blood Cells Mol Dis. 2010 Aug 15;45(2):124-7. Training Course on Haemoglobin Disorders 2011 27
Take home message Availability of relatively safe procedures Invasive or non-invasive New trends Complex procedures and not only technical 28
Thank you very much for your attention 29