A comprehensive analysis of chromosomal polymorphic variants on reproductive outcomes after intracytoplasmic sperm injection treatment

Challenges in classifying human chromosomal heteromorphisms using banding cytogenetics: From controversial guidelines to the need for a universal scoring system

Chromosomal heteromorphisms (CHs) are morphological variations predominantly found in constitutive heterochromatic regions of the genome, primarily composed of tandemly repetitive sequences of satellite DNA. Although not completely devoid of genes, these regions are typically not transcribed into proteins and lack obvious phenotypic impact. Nonetheless, their clinical importance is increasingly under scrutiny, with several studies aiming to assess their influence on human diseases and susceptibilities, especially as they are seemingly part of the long noncoding RNAs in certain tissues. This article summarizes the classification methods of human heterochromatic CHs documented in the literature over the last two decades. Multiple scoring systems have been identified, and previous approaches for CH assessment and reporting in genetic diagnosis have shown inconsistencies. Owing to the current heterogeneity in the classification of CHs, data analysis may be biased, impacting the quality of clinical reports and human genetic research. This review highlights the need for a universal scoring system, which is essential for scientific reproducibility and the accurate identification and clinical evaluation of human CHs.

Impacts of male chromosomal polymorphisms on semen quality and IVF/ICSI outcomes: A retrospective cohort study

OBJECTIVE

The study aims to elucidate the impacts of different types of male chromosomal polymorphisms (MCPs) on various outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.

METHODS

This retrospective cohort study included 1442 couples with normal karyotypes, 1442 couples with MCPs, 42 couples with male chromosomal rearrangements (MCRs), and 42 couples with MCRs combined with MCPs who underwent IVF/ICSI treatment at Peking University Third Hospital from 2015 to 2021. The semen quality, embryological outcomes, and clinical outcomes of different groups stratified by karyotypes were compared.

RESULTS

For couples undergoing IVF, male inv(9) was associated with a significantly lower sperm viability rate (29.41% vs 34.49%, P = 0.030), a lower progressive motility rate (25.13% vs 30.50%, P = 0.013), and a lower normal fertilization rate (52.41% vs 59.84%, P = 0.014). Male 9qh + was related to a lower sperm viability rate (27.56% vs 34.49%, P = 0.028). No MCPs were observed to compromise clinical outcomes in couples undergoing IVF. For couples undergoing ICSI, no MCPs exhibited an association with poorer semen quality and embryological outcomes. However, Yqh + and DGpstk+ were found to be significantly correlated with an increased likelihood of preterm birth (23.3% vs 9.2%, P = 0.003; 20.0% vs 9.2%, P = 0.041, respectively). In couples with MCRs, the presence of MCPs significantly reduced the sperm viability rate (19.99% vs 30.97%, P = 0.017) and progressive motility rate (8.07% vs 27.85%, P = 0.018).

CONCLUSION

Our study provides detailed evidence for the impacts of various MCPs on IVF/ICSI outcomes, reveals the complexity and heterogeneity of these impacts, and highlights the adverse effects of male inv(9).

Systematic analysis and evaluation of chromosome aberrations in major birth defects associated with infertility

Previous studies have indicated an elevated risk of infertility in certain birth defects, including congenital heart disease (CHD), hypospadias, cryptorchidism, and disorders of sexual development (DSD). Although the identification of chromosomal abnormalities or chromosomal aberrations (CAs) is crucial for the diagnosis of these conditions, the assessment of CAs in these disorders remains unclear, and few large-scale studies have been conducted at multiple centers. The aim of the current study was to systematically evaluate the prevalence of CAs in CHD, hypospadias, cryptorchidism, and DSD. Studies reporting CAs in these birth defects were retrospectively analyzed from 1991- 2023, using online databases such as PubMed and Google scholar as well as preprints and references from related literature. Comprehensive screening, data acquisition, and systematic assessments of the identified literature were performed. Ultimately, searches yielded a total of 7,356 samples from 14 published articles on CHD, 298 hypospadias cases from 4 published articles, 1,681 cryptorchidism cases from 4 published articles, and 2,876 DSD cases from 7 published articles. Carrier rates of CAs varied widely among these studies and conditions. A retrospective analysis revealed that CHD was associated with the highest carrier rate (26%) for CAs, followed by DSD (21%), hypospadias (9%), and cryptorchidism (5%). A subtype analysis of CAs indicated a higher prevalence of numerical abnormalities among the reported cases. Therefore, considering CAs in birth defects associated with infertility is imperative. This provides a foundation for the further clinical implementation of chromosomal screening and enhancing high-risk screening for individuals in the real world.