De novo balanced reciprocal translocation mosaic t(1;3)(q42;q25) detected by prenatal genetic diagnosis: a fetus conceived using preimplantation genetic testing due to a t(12;14)(q22;q13) balanced paternal reciprocal translocation

Introduction De novo balanced reciprocal translocations mosaicism in fetus conceived using preimplantation genetic testing from a different balanced translocation carrier parent has been rarely reported. Methods Chromosomal microarray analysis, karyotype analysis and fluorescent in situ hybridization were performed to verify the type and heredity of the rearrangement. STR analysis was conducted to identify potential contamination and verify kinship. In addition, a local BLAST engine was performed to locate potentially homologous segments which might contribute to the translocation in breakpoints of chromosome. Results A rare de novo balanced reciprocal translocations mosaicism mos 46,XY,t(1;3)(q42;q25)[40]/46,XY[39] was diagnosed in a fetus conceived using preimplantation genetic testing due to a 46,XY,t(12;14)(q22;q13) balanced translocation carrier father through multiplatform genetic techniques. Two of the largest continuous high homology segments were identified in chromosomal band 1q42.12 and 3q25.2. At the 21-months follow up, infant has achieved all psychomotor development milestones as well as growth within the normal reference range. Conclusion We present a prenatal diagnosis of a rare de novo balanced reciprocal translocations mosaicism in a fetus who conceived by preimplantation genetic testing. The most reasonable driving mechanism was that a de novo mitotic error caused by nonallelic homologous recombination between 1q42.12 and 3q25.2 in a zygote within the first or early cell divisions, which results in a mosaic embryo with the variant present in a half proportion of cells.

Balanced Reciprocal Translocation t(17;22)(p11.2;q11.2) and 10q23.31 Microduplication in a Infertility Male Suffering from Teratospermia

We describe the first case of two chromosomal abnormalities, balanced reciprocal translocation t(17;22)(p11.2;q11.2) and a microduplication in the region 10q23.31, in an infertility man suffering from teratospermia. Several genes located on the translocation breakpoints or the region of duplication show rich expression in the tissue of testis. They have been reported to be associated with developmental disorder and retardation, which might also be the risk factors affecting in spermatogonial differentiation and spermatogenesis. More studies should be carried out for identifification of new genes associated with semen quality. Our case might support the opinion that haploinsufficiency of the testis-expressed gene could be the cause of sperm immotility and abnormal sperm morphology. The two chromosomal abnormalities that carry additional reproductive risks, is apparently harmful with regard to the male infertility, and could contribute to the genomic instability resulting in disease.

The Influence of Sex on Embryo Development and Pregnancy Outcome in Preimplantation Genetic Testing for Chromosomal Translocation

Background To investigate the embryonic development and clinical pregnancy outcome of reciprocal translocation carriers and Robertsonian translocation carriers with different sex in preimplantation genetic testing (PGT). Methods A retrospective analysis of 1369 cycles of preimplantation genetic testing for structural rearrangements (PGT-SR) was performed in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from 2015 to 2019. All the patients were divided into reciprocal translocation and Robertsonian translocation according to the type of chromosomal translocation and divided into female carriers and male carriers according to the sex of the carriers. SPSS21.0 was used for data statistics and P < 0.05 indicated that the difference was statistically significant. Results The fertilization rate of female carriers(81.5%) with chromosomal structural abnormalities (including reciprocal translocation and Robertsonian translocation) was higher than that of male carriers(80.0%)(P=0.032), and the blastocyst formation rate of female carriers(50.0%) was lower than that of male carriers(54.8%)(P=0.016) in the same parental age. But there was no statistical difference in cleavage rate, high quality embryo rate, normal rate of biopsy, clinical pregnancy rate, abortion rate and live birth rate between female and male carriers. In the reciprocal translocation group, the blastocyst formation rate of male carriers (54.8%) was higher than that of female carriers (50.0%) (P=0.022) with the same parental age and there was no difference in pregnancy outcome. In the Robertsonian translocation group, the fertilization rate of male carriers (75.0%) was lower than that of female carriers (81.8%) (P=0.005) and the normal rate of biopsy (33.3%) was higher than that of female carriers (25.0%) (P=0.022) with the same parental age and there was no difference in pregnancy outcome. Conclusions In reciprocal translocation, male carriers have a higher rate of blastocyst formation rate than female carriers. In Robertsonianian translocation, male carriers have a higher noamal rate of biopsy than female carriers. However, there was no significant difference in pregnancy outcome between male carriers and female carriers with abnormal chromosome structure.

Balanced Chromosomal Rearrangements Associated with Hypoprolificacy in Australian Boars (Sus scrofa domesticus)

Balanced chromosomal rearrangements, mainly reciprocal translocations, are considered to be the causative agent of several clinical conditions in farmed pigs, resulting in hypoprolificacy and economic losses. Literature suggests that reciprocal translocations are heritable and can occur de novo. The prevalence rate of these balanced structural rearrangements of chromosomes differs from country to country and varies between 0.5% and 3.3%. The Australian pig population is descendent of a small founder population and has since been a closed genetic group since the 1980s. Hence, any incident of reciprocal translocation along with the pedigree of boars that contribute sperm for artificial insemination has the potential to have an economic consequence. To date, there has been no published account for screening of reciprocal translocation associated with hypoprolificacy in the Australian pig population. In this study, we performed standard and molecular cytogenetic analyses to identify evidence of chromosome rearrangements and their association with hypoprolificacy in a representative 94 boar samples from a commercial nucleus herd. We identified three novel rearrangements between chromosomes 5 and 14, between chromosomes 9 and 10, and between chromosomes 10 and 12. In addition, we also detected a reciprocal translocation between chromosomes 3 and 16 that has previously been detected in pig herds in France. The prevalence rate was 6.38% within the samples used in this study. All four rearrangements were found to have an association with hypoprolificacy. Further study and routine monitoring will be necessary to identify any further rearrangements that will allow breeders to prevent the propagation of reciprocal translocations from generation to generation within the Australian pig population.