In vitro fertilization and preimplantation genetic testing methods in infertility treatment of a woman with karyotype 46,XX,ins(13;4)(q34;p14p15.3),inv(4)(p14q12). Case report

The frequency of structural chromosomal transpositions can range from 1.8 to 8% among patients with reproductive disorders. There are several types of the rarest chromosomal abnormalities: insertion (insertion of a chromosomal region) and inversion (rotation of a chromosome region). This article describes a clinical case of the infertility treatment using assisted reproductive technologies in a woman with a rare chromosomal abnormality: simultaneous insertion and inversion of chromosomes – 46, XX, ins (13;4)(q34;p14p15.3), inv(4)(p14q12). The structure and frequency of chromosomal aberrations were determined by high-throughput sequencing in preimplantation embryos. The result of the sequencing analysis showed that unbalanced variants for a known pathology were detected in 9 (56.3%) out of 16 observations, while in 6 (37%) only for a pathology known in the karyotype and in 3 (19%) they were presented simultaneously with the pathology of other chromosomes or with mosaicism. According to the results of the study, in preimplantation embryos, where one of the parents had chromosomal abnormalities, in addition to unbalanced variants, there is aneuploidy of other chromosomes not involved in the known pathology. They are described in 3 (21%) out of 14 observations of all identified pathology. In this regard, patients with aberrations in the karyotype are recommended, whenever possible, to carry out preimplantation genetic testing of structural rearrangements by methods allowed to analyze all chromosomes simultaneously. For example, high-throughput sequencing on the Illumina platform may become an alternative for prenatal diagnostics, which is performed in fertile couples with high risk of having a child with hereditary or congenital disorders. In the case of detection of chromosomal changes in the fetus, patients are faced with a number of ethical issues related to the necessity for medical abortion, which may contradict their religious and moral convictions.