Background: The subtelomeric REARRANGEMENTS are increasingly being investigated in cases of idiopathic intellectual disabilities (ID) and congenital abnormalities (CA) but are also thought to be responsible for unexplained recurrent miscarriage (RM). Such REARRANGEMENTS can go unnoticed through conventional cytogenetic techniques and are undetectable even with high-resolution molecular cytogenetic techniques such as array comparative genomic hybridization (aCGH), especially when DNA of the stillbirth or families are not available. The aim of the study is to evaluate the rate of subtelomeric REARRANGEMENTS in patients with RM.Materials and Methods: In this cross-sectional study, fluorescent in situ hybridization (FISH), based on ToTelVysion telomeric probes, was undertaken for 21 clinically normal couples exhibiting a “normal” karyotype with at least two abortions. Approximately 62% had RM with a history of stillbirth or CA/ID while the other 38% had only RM.Results: FISH detected one cryptic rearrangement between chromosomes 3q and 4p in the female partner of a couple (III: 4) [46, XX, ish t (3; 4) (q28-, p16+; p16-, q28+) (D3S4559+, D3S4560-, D4S3359+; D3S4560+, D4S3359-, D4S2930+)] who presented a history of RM and family history of ID and CA. Analysis of the other family members of the woman showed that her sisters (III: 6 and III: 11) and brother (III: 8) were also carriers of the same subtelomeric translocation t (3; 4) (q28; p16).Conclusion: We conclude that subtelomeric FISH should be undertaken in couples with RM especially those who not only have abortions but also have had at least one child with ID and/or CA, or other clinically recognizable syndromes.For balanced and cryptic anomalies, subtelomeric FISH still remains the most suitable and effective tool in characterising such chromosomal REARRANGEMENTS in RM couples.

Background: Chromosomal REARRANGEMENTS play an important role in infertility. Carriers of chromosomal REARRANGEMENTS have a lower chance of producing normal or balanced gametes due to abnormal segregation of chromosomes at meiosis, which leads to recurrent spontaneous abortions and infertility. Preimplantation genetic testing for structural chromosome REARRANGEMENTS (PGT-SR) is offered to couples who have balanced chromosomal REARRANGEMENTS in order to select embryos with a balanced karyotype prior to implantation, thereby increasing the chances of pregnancy. The purpose of the current study was to assess the outcomes of PGT-SR in patients carrying various balanced chromosomal REARRANGEMENTS and to assess their clinical pregnancy outcome after in vitro fertilization (IVF). Methods: In this study, infertile couples with balanced chromosomal abnormalities undergoing PGT-SR were retrospectively analyzed at a single fertility center from January 2016 to December 2019. Results: PGT-SR was performed on 87 embryos from 22 couples in whom one partner carried a balanced translocation or an inversion. Fifty-seven (65. 5%) of these embryos had unbalanced or sporadic aneuploidies, 30 (34. 5%) embryos were normal or chromosomally balanced, which were then transferred in 18 couples. A higher rate of unbalanced translocations in comparison to sporadic aneuploidies was observed in couples with reciprocal translocation. The live birth rate per embryo transfer was found to be 66. 6% (12/18). Conclusion: PGT-SR is a useful tool in selecting normal or balanced embryos for transfer in IVF, which could lead to a pregnancy by reducing the chance of miscarriages due to chromosome aneuploidy in couples with balanced chromosomal REARRANGEMENTS.