Corella Cano, Sara

Universitat Autònoma de Barcelona. Facultat de Biociències

Diposit Digital de Documents de la UAB

Preimplantation genetic diagnosis in asymptomatic carriersSara Corella Cano. Grau Biotecnologia, Universitat Autònoma de BarcelonaPreimplantation genetic diagnosis (PGD) is defined as the in vitro testing for Mendelian, chromosomal and mitochondrialdefects in preimplantation stages embryos or oocytes and an alternative for pre-natal diagnosis and selective termination ofpregnancy in couples with a high risk of affected offspring.There are some detractor groups against the application of PGD in general, although some indications are specially ethicallydifficult, such as non-disclosure PGD for late-onset diseases: patients do not wish to know their carrier status but want to havedisease-free offspring.1. Assisted Reproductive Technology (a. IVF; b. ICSI)2. Genetic material obtaining (a. Biopsy of polar-bodies; b. Biopsy of blastomeres; c. Biopsy of blastocyst cells)3. Analysis of cells obtained (a. Molecular analysis; b. Cytogenetic analysis)1.a. 1.b. 2.a. 2.b.2.c. 3.a. 3.b.1. Non-disclosure PGD (asymptomatic carrier parents)ü Parents do not want to know their carrier status but dowant to have disease-free offspringPuts practitioners in a difficult ethical position:- Undertake PGD cycles even when the results ofprevious cycles preclude the individual as a carrier- Having to do mock-transfers if no embryos areavailableà The ESHRE ethics task force encourage exclusion testing (the mutation itself is not analysed)2. Late-onset diseases and cancer predisposition• Late-onset diseases (such as Huntington’s disease andAlzheimer’s disease)ü Usually complete penetrance and incurableü Burden imposed by the eventual fate in late-onsetdiseasesOffspring have a normal life before the onset of thedisease• Cancer predispositionü Severe diseaseü Burden on the quality of life imposed by far-reachingpreventive measures in cancer predisposition syndromesGenetic cancer predisposition doesn’t ensure thedevelopment of the disease3. Carrier embryosü Pathology disappears of the familyü Offspring won’t have to use techniques such as PGD toavoid the disease in their own offspringNegative selection of healthy carrier embryosIf there are only carrier embryos available, parents willhave to decide to transfer them or notAccording to the Spanish Law 14/2006, PreimplantationGenetic Diagnosis with purposes other than the detectionof early-onset severe diseases or alterations that maycompromise the viability of the embryo requires theapproval of the competent sanitary authority after afavorable report from the National Human AssistedReproduction Commission, which must evaluate the clinical,therapeutic and social features in each case.• Preimplantation genetic diagnosis is a useful tool forpreventing hereditary genetic diseases and increases theprobability of a successful pregnancy in assistedreproduction techniques.• Nowadays, PGD enables diagnosis of a broad range ofgenetic diseases but there are many not diagnosablediseases, its efficiency is still limited and it presents somedetractor sectors that critic its application.à However, some experts call PGD the medicine of thefuture.IntroductionMaterial and methodsEthical issues LegislationConclusions• Geraedts JPM, De Wert GMWR. Preimplantation genetic diagnosis. Clinical Genetics 2009: 76: 315–325• Sermon K, Van Steirteghem A, Liebaers I. Preimplantation genetic diagnosis. The Lancet 2004; 363: 1633-41• ESHRE PGD Consortium Steering Committee. ESHRE Preimplantation Genetic Diagnosis Consortium: data collection III (May 2001). Hum Reprod 2002; 17: 233–46.• Ley 14/2006, de 26 de mayo, sobre técnicas de reproducción humana asistida. Boletín Oficial del Estado (BOE)Figures:1.a.: http://www.reproduccionasistida.org/zona/fecundacion-in-vitro/1.b.: http://www.infertile.com/brochures/Treating_Infertility.pdf2.a.: http://www.northwestfertility.co.uk/preimplantation.aspx2.b./3.b.: Sermon K, Van Steirteghem A, Liebaers I. Preimplantation genetic diagnosis. TheLancet 2004; 363: 1633-412.c.: http://www.prweb.com/releases/DFA/2012/prweb10229756.htm3.a.: Geraedts JPM, De Wert GMWR. Preimplantation genetic diagnosis. Clinical Genetics 2009:76: 315–325Bibliography and References

Preimplantation genetic diagnosis in asymptomatic carriers

http://ddd.uab.cat/pub/tfg/2013/114645/Poster_SaraCorellaCano.pdf

Preimplantation genetic diagnosis in asymptomatic carriers

Abstract

Similar works

Full text

Available Versions

Diposit Digital de Documents de la UAB