Pre-implantation Genetic Diagnosis ( PGD )
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PGD (preimplantation genetic diagnosis) is an advanced procedure paired with IVF to test embryos for genetic conditions before implantation. Since its introduction in 1990, over 100,000 healthy babies have been born due to PGD, which allows for the identification of severe genetic disorders and increases pregnancy success rates while reducing the risks associated with genetic diseases. Future advancements aim to refine PGD techniques, enhancing its reliability and expanding its applications in reproductive medicine.
Pre-implantation Genetic Diagnosis ( PGD )
- 2. • PGD is a state-of-the-art procedure used in conjunction with In Vitro Fertilization (IVF) in which the embryo is tested for certain conditions prior to being placed in the womb of the woman. • PGD was first reported in 1990. • PGD combines the recent advances in molecular genetics and in assisted reproductive technology
- 3. 3 World-wide, over 100,000 babies were born thanks to PGD
- 4. 44 Embryo biopsy Diagnosis by Transfer 1-2 unaffected embryos Fertilisation in vitro (IVF or ICSI) PCRFISH Accurate genetic diagnosisAppropriate Genetic Counselling DENATURING ANNEALING EXTENSION PRIMER TAQ TAQ
- 12. Ovarian Stimulation IVF Blastomere Biopsy on Day 3 Genetic Analysis Transfer of Unaffected Embryo Outcome Chromosomally Normal Baby
- 13. • Polar Body • Cleavage Stage • Blastocyst
- 17. • Polymerase Chain Reaction (PCR). • Fluorescence In Situ Hybridization (FISH). • CGH 24. • DNA Microarrays. • NGS ( next generation sequencing ).
- 20. • Chromosomal Disorders • Chromosomal rearrangements • Inversions • Translocations • Chromosome Deletions • Gender determination for severe X-linked diseases
- 21. • Severe monogenic diseases (cystic fibrosis, ß thalassaemia, sickle cell anemia, fragile X syndrome, myopathies) • Recurrent pregnancy loss. • Advanced MaternalAge. • Couples with >3 IVF failures. • Epididymal or Testicular sperm aspiration with >1 IVF failures.
- 22. • Unexplained infertility. • Y-chromosome deletion: found in 5-20% men with low sperm count. • Couples who have previously had a pregnancy with a chromosomal abnormality . • couples where one partner carries a balanced chromosomal translocations.
- 23. AUTOSOMAL RECESSIVE Cystic fibrosis (various mutations) Tay Sachs disease b-thalassaemia Sickle cell anaemia Rh blood typing Spinal muscular atrophy Adrenogenital syndrome Congential adrenal hyperplasia Plakophilin-1 (PKP1) MCAD CDG1C Epidermolysis bullosa Gaucher’s disease Hyperinsulinemic hypoglycemia PHH1 Fanconii’s anemia HLA matching TRIPLET REPEATS Fragile X Myotonic dystrophy Huntingtons AUTOSOMAL DOMINANT Marfans syndrome Charcot-Marie Tooth disease (type 1A) Crouzons syndrome NF2 OsteogenesisimpeerfectaI and IV Stickler syndrome Tuberous sclerosis Central core disease Familial adenomatous polyposis Li Fraumeni syndrome Retinoblastoma SPECIFIC DIAGNOSIS OF X-LINKED Lesch Nyhan syndrome Duchenne muscular dystrophy Charcot-Marie Tooth disease Retinitis pigmentosum Ornithine Transcarbamylase Haemophilia Agammaglobulinemia Alport syndrome Hunter’s sndrome MPSII Oro-facial-digital syndrome type I
- 24. • X-linked, agammaglobulinemia • Spinal and bulbar muscular atrophy • FG syndrome • DAZ deletion • Ataxia telangiectasia • Familial amyloidotic polyneuropathy • Genodermatosis (PKP1) • Charcot-Marie-Tooth type IA • Citrullinemia • Holoprosencephaly (SSH gen) • Kelley-Seegmil syndrome • X-linked epilepsy (paternal side) • Mitochondrial MELAS • Pelizaeus Merzbacher • Junctional epidermolisis bullosa • Hyperinsulinemic hypoglycemia PHH1 • Fabry’s disease • Bloom disease • Anemia • FAP-Gardner • CF+XL mental retardation (X2) • Oro-facial-digital syndrome type 1 • Incontinentia pigment • RhD sensitization • Adrenoleukodystrophy • Osteogenesis imperfecta • CDG1C • Skin fragility • Alfa-1-antitrypsin deficiency • Hypophosphatasia • Lesch Nyhan syndrome • Long-chain 3-hydroxyacyl-coa dehydrogenase deficiency • Marfan disease • Fragile X • Retinoblastoma • Gaucher disease • Congenital adrenal hyperplasia • Tuberosclerosis • Stickler syndrome • Neurofibromatosis • Crouzon syndrome • ZFX/ZFY • β-thalassemia • Sickle cell anemia • Cystic fibrosis • Spinal muscular atrophy • Myotonic dystrophy • Duchenne muscular dystrophy • Hemophilia AB • Epidermolizis bullosa • Multiple epiphyseal dysplasia • Phenylketonuria (PKU) • Achondroplasia • X-linked hydrocephaly • Retinitis pigmentosa • Huntington disease • Hurler syndrome • Hunter syndrome • OCT • Tay-Sach’s disease • Alport disease • Machado-Joseph disease • Glicogen Storage disease • Koroideremi • X-linked autism
- 25. • Increased Implantation Rate. • Reduction in Pregnancy Losses. • Reduction in the Chance of Having a Child with Aneuploidy. • Reduces the possibility of having to choose to terminate the pregnancy following a diagnosis of a probable genetic disorder.
- 26. • The birth of a(nother) child with a genetic disorder. • Invasive diagnostic procedures including CVS and amniocentesis. • Possibility of an established pregnancy termination. • Risk of miscarriage due to genetic disorders • Risk of future fertility problems.
- 27. • Embryo damage Oocyte and Embryo Biopsy are invasive procedures • Misdiagnosis The accuracy of the PGD for translocation is 90%. • False negative result • False positive result • The chance for NO result • The chance for mosaicism • IVF Risks
- 29. • Not Achieving Pregnancy • There may not be any normal embryos available for transfer. • The embryos may not implant and develop even if they do not have the defect. • The workup for PGD is expensive and labor intensive.
- 31. Future of PGD • Efforts continue to be focused on improving methods to obtain an accurate diagnosis. • PGD holds great promise for the future as techniques and genetic tests are perfected. • PGD may become routine in the next few years.
- 33. • PGD is a reliable procedure in preventing the birth of affected children . • PGD of aneuploidy is effective and results in a high take home baby rate when implemented in certain categories of patients. • Despite the efficiency of the PGD technique, conventional prenatal diagnosis is still required by most PGD laboratories