Genetics of recurrent pregnancy loss among Iranian population

Association of Y chromosome AZF region microdeletions with recurrent miscarriage in Iranian couples: A case-control study

BACKGROUND

Recent studies have linked recurrent pregnancy loss (RPL) to abnormalities in the sperm genome, specifically microdeletions in the azoospermia factor (AZF) region. This study investigated the potential association between Y chromosome microdeletions in the AZF region and RPL in Iranian couples.

METHODS

The research presents a case-control study of 240 men: 120 whose partners experienced recurrent miscarriage, and 120 who had successful pregnancies without history of miscarriage. The study used semen parameters, hormone analyses, and microdeletion analysis via multiplex PCR and the YChromStrip kit. Thus, the sequence-tagged site (STS) markers of AZFa (sY84, sY86), AZFb (sY127, sY134), and AZFc (sY254, sY255) regions were examined.

RESULTS

The variations in semen parameters and sex hormone levels between cases and controls are suggest impaired testicular function in men whose partners had recurrent miscarriages (p < 0.05). Furthermore, the study revealed a negative correlation between sperm count and follicle-stimulating hormone (FSH) level, and a positive one between sperm motility and testosterone concentration. There were no microdeletions in the control group, while the RPL group showed 20 deletions in AZFb (sY134) (16.66%) and 10 deletions each in AZFb (sY127) (8.33%) and AZFc (sY254) (8.33%).

CONCLUSION

Microdeletions in sY134 (AZFb) were significantly associated with RPL in Iranian men (p = 0.03). AZF microdeletion screening in couples with RPL can provide valuable information for ethnical genetic counseling and management of recurrent miscarriage. Further studies on larger populations or across various ethnic groups, conclusions and the inclusion of other factors like epigenetic changes explain the role of AZF microdeletions in RPL.

Association of Genetic Polymorphisms in Long Noncoding RNA HOTTIP with Risk of Idiopathic Recurrent Spontaneous Abortion

The clustered homeobox gene family known as the Hox family plays a fundamental role in the morphogenesis of the vertebrate's embryo. A long noncoding RNA (lncRNA), known as HOTTIP (HOXA transcript at the distal tip), has been functionally characterized and contributed to the pathogenesis of various conditions. The current case-control study was undertaken to examine the gene frequencies and shared alleles of the HOTTIP  gene in Iranian participants with or without idiopathic recurrent spontaneous abortion (RSA). Both ARMS-PCR reaction and RFLP-PCR techniques were employed to detect three HOTTIP polymorphisms (rs2023843C/T, rs78248039A/T, and rs1859168C/A) in a DNA sample of 161 women with RSA and 177 healthy women. We found that the TT genotype of the HOTTIP rs2023843 C/T polymorphism was associated with a lower risk for idiopathic RSA. In contrast, the TT genotype of the HOTTIP rs78248039 A/T polymorphism was correlated with an enhanced risk of RSA. The presence of the A-allele for HOTTIP rs1859168 C/A polymorphism was associated with an increased risk for idiopathic RSA. Haplotype analysis showed that the T/T/A, C/T/A, T/T/C, and T/A/A haplotypes of rs2023843/rs78248039/rs1859168 enhanced RSA susceptibility. Computational analysis predicted that this lncRNA might act as a potential sponge for some microRNAs; therefore, affecting the expression of genes being targeted by them. In addition, both rs2023843 and rs1859168 variants could alter the local secondary structure of HOTTIP. Our results showed that HOTTIP rs2023843C/T, rs78248039A/T, and rs1859168C/A polymorphisms may confer genetic susceptibility to idiopathic RSA in an Iranian population.

Chromosome analysis of foetal tissue from 1903 spontaneous abortion patients in 5 regions of China: a retrospective multicentre study

BACKGROUND

Abnormal foetal tissue chromosome karyotypes are one of the important pathogenic factors for spontaneous abortion (SA). To investigate the age and abnormal foetal karyotypes of 1903 couples who experienced SA.

METHODS

A retrospective multicentre study collected age and foetal tissue karyotypes CNV-seq data of 1903 SA couples from 6 hospitals in 5 regions from January 2017 to March 2022. The distribution and correlation of abnormal foetal tissue karyotypes were evaluated by using regions and age.

RESULTS

In our study, 1140 couples (60.5% of the total) had abnormal foetal tissue chromosome karyotypes in all regions. We found that there were differences in the number of abnormal foetal tissue chromosome karyotypes, of which the incidence of trisomy was higher. At the same time, the populations situated in the eastern region had a more triploid (15.5%) distribution, trisomy (58.1%) in the southern region, mosaicism (14.8%) and microduplication (31.7%) in the southwestern region, microdeletion (16.7%) in the northern region. There are variances across areas, and it is more common in the north. The incidence risk of prenatal chromosomal abnormalities varied according to age group.

CONCLUSION

The findings of this study suggest that the karyotypes of patients with abnormal foetal tissue chromosome abortion in different regions were different. Meanwhile, patients ≥ 35 years old had a higher risk of abnormal foetal tissue chromosome abortion.

Combined Parental Thrombophilia Gene Mutation Defects in Couples with Repeated Pregnancy Loss

Background

Several genetic mutations in female thrombotic defects have recently been shown to affect recurrent pregnancy loss (RPL); however, it is unclear which common parental mutations are involved in thrombosis-associated repeated pregnancy loss RPL.

Aims

In this study, the prevalence of some combined parental thrombophilia gene mutation defects was studied in couples with RPL.

Settings and Design

The observational study was done in babol infertility research center (Iran) in 2022.

Materials and Methods

Sixty-two infertile women with a history of RPL and their male partners (124 individuals) participated in this study. The frequencies of common defects associated with methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, factor V Leiden, protein C, protein S and homocysteine were analysed in these couples.

Statistical analysis used

The data were statistically analysed using the Mann-Whitney test.

Results

Sixty-two couples (124 individuals) were analysed. 56.2% of couples with a history of RPL had MTHFR C677T and 23.1% had MTHFR A1298C. Forty percent of couples showed homocysteine deficiency and 12.5% protein C deficiency. Other genes tested were only observed in the mother or father but not both.

Conclusions

Results obtained with RPL couples demonstrate the importance of further investigating combined parental thrombophilia gene mutation defects (not only maternal).

Hormone supply to the pituitary gland: A comprehensive investigation of female‑related tumors (Review)

The hypothalamus acts on the pituitary gland after signal integration, thus regulating various physiological functions of the body. The pituitary gland includes the adenohypophysis and neurohypophysis, which differ in structure and function. The hypothalamus-hypophysis axis controls the secretion of adenohypophyseal hormones through the pituitary portal vein system. Thyroid-stimulating hormone, adrenocorticotropic hormone, gonadotropin, growth hormone (GH), and prolactin (PRL) are secreted by the adenohypophysis and regulate the functions of the body in physiological and pathological conditions. The aim of this review was to summarize the functions of female-associated hormones (GH, PRL, luteinizing hormone, and follicle-stimulating hormone) in tumors. Their pathophysiology was described and the mechanisms underlying female hormone-related diseases were investigated.

Chromosomal Copy Number Variation Analysis in Pregnancy Products from Recurrent and Sporadic Miscarriage Using Next-Generation Sequencing

Chromosomal abnormality is one of the causes of fetal miscarriage. The potential differences of fetal chromosomal abnormalities in sporadic miscarriage (SM) and recurrent miscarriage (RM) remain unclear. The purpose of this study was to investigate copy number variations (CNVs) in SM and RM to provide useful genetic guidance for pregnancy and prenatal diagnosis. Four hundred eight samples of aborted fetuses were analyzed by CNV sequencing, and further functional enrichment analysis was performed. Chromosomal abnormalities were identified in 218 (53.4%) fetuses. There were 62 cases (15.2%) with structural chromosomal abnormalities, including 41 with VUS CNVs, 8 with pathogenic CNVs (pCNVs), and 5 with likely pCNVs. Duplications or deletions of 7p22, 8p22, 8p23, and Xp22.31 were significantly more common in RM cases and therefore believed to be related to RM. A total of 289 genes were identified, and 29 different functions were enriched as potential RM candidate genes and functions, which were mainly concentrated in 4 functional categories: chemokines and chemotaxis, protease activity and protein modification, defense response to bacterial and fungal infections, and immune response. The results of this study may improve our understanding of the etiology of RM and contribute to the establishment of a population-based genetic marker information for RM.

Genetics and molecular biology of male infertility among Iranian population: an update

Infertility is one of the main social and health problems among young couples. Although a noticeable ratio of infertilities are asymptomatic, about half of the cases are observed among males. Various environmental factors such as life style, dietary patterns, and pathogens are associated with male infertility. Mutations and chromosomal abnormalities are also the most important genetic risk factors of male infertility. Similar to other populations, there is a dramatically rising trend of male infertility among Iranian. Regarding the high ratio of asymptomatic cases, it is required to clarify the molecular biology and cellular processes involved in male infertility in this population to suggest an efficient panel of diagnostic markers. In this review, we have summarized all of the cellular and molecular processes which have been reported among Iranian infertile males to clarify the molecular biology of male infertility in this population. It was observed that the stress response, cellular detoxification, and DNA repair processes were the most common aberrant cellular mechanisms among Iranian infertile males. This review paves the way of introducing a population-based diagnostic panel of genetic markers among Iranian infertile males.

Association of FOXP3 rs3761548 polymorphism and its reduced expression with unexplained recurrent spontaneous abortions: A South Indian study

PROBLEM

Fork Head Box Protein 3 (FOXP3) is an X-linked gene, codes for a master transcription regulatory protein that controls the development and function of immunosuppressive T regulatory (Treg) cells. They are crucial mediators of maternal foetal tolerance and successful pregnancy outcome. The aim of the study is to evaluate the association of FOXP3 rs3761548 functional polymorphism and to assess the serum concentrations of full-length FOXP3 protein in Unexplained Recurrent Spontaneous Abortions (URSA) patients of Southern India.

METHOD OF STUDY

The study included blood samples from 150 URSA patients and 150 healthy, pregnant parous women. Polymerase Chain Reaction-Restriction Fragment Length Polymorphism was done for rs3761548 FOXP3 genotyping. Serum concentrations of full-length FOXP3 protein were estimated by enzyme-linked immunosorbent assay.

RESULTS

The frequencies of mutant A allele, CA and AA genotypes of rs3761548 functional polymorphism were significantly elevated in patients compared to healthy, pregnant parous women and exhibited a two, three and twofold increased risk respectively towards URSA. Serum concentrations of full-length FOXP3 protein were high in controls compared to patients (10.14 ± .30 vs. 8.84 ± 1.73 ng/ml; p < .05).

CONCLUSION

Our results advocate an association of FOXP3 rs3761548 polymorphism and reduced expression of full-length FOXP3 protein with URSA.

Sex-Biased lncRNA Signature in Fetal Growth Restriction (FGR)

Impaired fetal growth is one of the most important causes of prematurity, stillbirth and infant mortality. The pathogenesis of idiopathic fetal growth restriction (FGR) is poorly understood but is thought to be multifactorial and comprise a range of genetic causes. This research aimed to investigate non-coding RNAs (lncRNAs) in the placentas of male and female fetuses affected by FGR. RNA-Seq data were analyzed to detect lncRNAs, their potential target genes and circular RNAs (circRNAs); a differential analysis was also performed. The multilevel bioinformatic analysis enabled the detection of 23,137 placental lncRNAs and 4263 of them were classified as novel. In FGR-affected female fetuses’ placentas (ff-FGR), among 19 transcriptionally active regions (TARs), five differentially expressed lncRNAs (DELs) and 12 differentially expressed protein-coding genes (DEGs) were identified. Within 232 differentially expressed TARs identified in male fetuses (mf-FGR), 33 encompassed novel and 176 known lncRNAs, and 52 DEGs were upregulated, while 180 revealed decreased expression. In ff-FGR ACTA2-AS1, lncRNA expression was significantly correlated with five DEGs, and in mf-FGR, 25 TARs were associated with DELs correlated with 157 unique DEGs. Backsplicing circRNA processes were detected in the range of H19 lncRNA, in both ff- and mf-FGR placentas. The performed global lncRNAs characteristics in terms of fetal sex showed dysregulation of DELs, DEGs and circRNAs that may affect fetus growth and pregnancy outcomes. In female placentas, DELs and DEGs were associated mainly with the vasculature, while in male placentas, disturbed expression predominantly affected immune processes.

Genetics of recurrent pregnancy loss among Iranian population

Background

Recurrent pregnancy loss (RPL) is one of the most common reproductive disorders which is defined as the occurrence of recurrent miscarriage before 24 weeks of gestation and is observed among 1%–5% of women.

Methods

Various factors are associated with RPL such as immunological disorders, maternal age, obesity, alcohol, chromosomal abnormality, endocrine disorders, and uterine abnormalities. About half of the RPL cases are related with chromosomal abnormalities. Therefore, RPL genetic tests are mainly limited to karyotyping. However, there is a significant proportion of RPL cases without any chromosomal abnormalities that can be related to the single‐gene aberrations. Therefore, it is required to prepare a diagnostic panel of genetic markers besides karyotyping.

Results

In the present review, we have summarized all the significant reported genes until now which are associated with RPL among Iranian women. We categorized all the reported genes based on their cellular and molecular functions in order to determine the molecular bases of RPL in this population.

Conclusion

This review paves the way of introducing a population‐based diagnostic panel of genetic markers for the first time among Iranian RPL cases. Moreover, this review clarifies the genetic and molecular bases of RPL in this population.