title: Can Characteristics of Reciprocal Translocations Predict the Chance of Transferable Embryos in PGD Cycles?
abstract: Translocation carriers have an increased risk of miscarriage or the birth of a child with congenital anomalies. Preimplantation genetic diagnosis (PGD) is performed in translocation carriers to select for balanced embryos and, thus, increase the chance of an ongoing pregnancy. However, a common experience is that reciprocal translocation carriers produce a high percentage of unbalanced embryos, which cannot be transferred. Therefore, the pregnancy rates in PGD in this patient group are low. In a cohort of 85 reciprocal translocation carriers undergoing PGD we have searched for cytogenetic characteristics of the translocations that can predict the percentage of balanced embryos. Using shape algorithms, the most likely segregation mode per translocation was determined. Shape algorithm, breakpoint location, and relative chromosome segment sizes proved not to be independent predictors of the percentage of balanced embryos. The ratio of the relative sizes of the translocated segments of both translocation chromosomes can give some insight into the chance of transferable embryos: Very asymmetrical translocations have a higher risk of unbalanced products (p = 0.048). Counseling of the couples on the pros and cons of all their reproductive options remains very important.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, GZ Groningen 9713, The Netherlands. e.c.dul@umcg.nl.
authors.forename: Elsbeth
authors.initials: E
authors.lastname: Dul
authors.affiliation: Department of Obstetrics and Gynaecology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, GZ Groningen 9713, The Netherlands. j.van.echten@umcg.nl.
authors.forename: Jannie
authors.initials: J
authors.lastname: van Echten-Arends
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, GZ Groningen 9713, The Netherlands. h.groen01@umcg.nl.
authors.forename: Henk
authors.initials: H
authors.lastname: Groen
authors.affiliation: Department of Reproductive Medicine, University Medical Center Utrecht, Heidelberglaan 100, CX Utrecht 3584, The Netherlands. peter_kastrop@hotmail.com.
authors.forename: Peter
authors.initials: P
authors.lastname: Kastrop
authors.affiliation: Department of Obstetrics & Gynaecology, Academic Hospital Maastricht, P. Debyelaan 25, HX Maastricht 6229, The Netherlands. lucie.amory@mumc.nl.
authors.forename: Lucie Amory-van
authors.initials: LA
authors.lastname: Wissen
authors.affiliation: Department of Clinical Genetics, Academic Hospital Maastricht, P. Debyelaan 25, HX Maastricht 6229, The Netherlands. john.engelen@mumc.nl.
authors.forename: John
authors.initials: J
authors.lastname: Engelen
authors.affiliation: Department of Obstetrics and Gynaecology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, GZ Groningen 9713, The Netherlands. j.a.land@umcg.nl.
authors.forename: Jolande
authors.initials: J
authors.lastname: Land
authors.affiliation: Department of Obstetrics & Gynaecology, Academic Hospital Maastricht, P. Debyelaan 25, HX Maastricht 6229, The Netherlands. edith.coonen@mumc.nl.
authors.forename: Edith
authors.initials: E
authors.lastname: Coonen
authors.affiliation: Department of Genetics, University of Groningen, University Medical Center Groningen, Hanzeplein 1, GZ Groningen 9713, The Netherlands. c.m.a.van.ravenswaaij@umcg.nl.
authors.forename: Conny
authors.initials: C
authors.lastname: van Ravenswaaij-Arts
keywords: Robertsonian translocation; meiotic segregation; preimplantation genetic diagnosis (PGD); reciprocal translocation