Preimplantation genetic testing using Karyomapping for a paternally inherited reciprocal translocation: a case study

Abstract

Purpose Preimplantation genetic testing (PGT) using Karyomapping is used to screen embryos for single gene disorders prior to implantation. While Karyomapping is not designed to screen for abnormalities in chromosome copy number, this testing is based upon a genome-wide analysis of single nucleotide polymorphisms (SNP) and, as such, some chromosome abnormalities are detected. The aim of this study was to validate whether Karyomapping could provide reliable and accurate PGT for a paternal 46,XY,t(10;19)(p15;p13.3) reciprocal translocation. Methods Feasibility/validation for PGT was performed using DNA from the couple, as well as DNA from the paternal parents and from a previous unbalanced pregnancy. Karyomapping was performed using Illumina's HumanKaryomap-12 BeadChip microarray technology. SNP analysis was performed using BlueFuse Multi software (Illumina). Transmission of the translocation was assessed through the analysis of SNP markers on the chromosome regions of interest. Results PGT-SR was determined to be feasible as chromosomal SNP analysis could reliably distinguish normal/balanced outcomes from all unbalanced outcomes. The couple transferred a normal/balanced embryo in an elective single embryo transfer procedure following 2 IVF/PGT-SR cycles. A clinical pregnancy was achieved. Conclusion This is the first report of PGT-SR test validation using Karyomapping for a 46,XY,t(10;19)(p15;p13.3) reciprocal translocation. Karyomapping may offer a means of detecting unbalanced forms of chromosome rearrangements when other PGT platforms fail.

One healthy live birth after preimplantation genetic testing of a cryptic balanced translocation (9;13) in a family with cerebral palsy and glaucoma: a case report

“…The preimplantation genetic testing technique has been exploited to help balanced translocation carriers give birth to healthy offspring [ 5 , 14 , 15 ], while only one case has been reported regarding assisted reproduction for cryptic balanced translocation carriers [ 10 ] with no successful pregnancy, which may be related to the high rate of chromosome abnormalities in embryos with translocations with terminal breakpoints [ 16 ]. In our study, only one balanced and no normal embryos were acquired in a total of 5 embryos biopsied in 2 PGT cycles, a very low incidence of normal or balanced embryos consistent with the other reported result [ 10 ].…”

In Vitro Fertilization Using Preimplantation Genetic Testing in a Romanian Couple Carrier of Mutations in the TTN Gene: A Case Report and Literature Review

“…Preimplantation genetic testing using karyomapping has proven its usefulness in obtaining healthy embryos and subsequent successful pregnancies in which myotonic dystrophy type I (MDI) [ 22 , 23 , 24 , 25 ], Duchenne muscular dystrophy (DMD) [ 26 , 27 ], muscular atrophy [ 28 ] are avoided. This approach has also been applied effectively for averting the consequences of other genetic events such as reciprocal translocation [ 29 ] and dynamic mutation [ 30 ].…”

Should non-invasive prenatal testing be recommended for patients who achieve pregnancy with PGT?

“…The sequencing data of the NGS platform were analysed by Peking Jabrehoo Med Tech Co., Ltd. The data of the Karyomapping platform were analysed by BlueFuse Multi V4.0 (Illumina) [ 29 , 30 ].…”