Introduction Cytogenetic abnormalities are a major genetic cause of infertility and recurrent early pregnancy loss (REPL), conditions that affect a substantial proportion of couples of reproductive age. Both numerical and structural chromosomal abnormalities can impair gametogenesis, fertilization, implantation, or embryonic development. This study aimed to evaluate the frequency, spectrum, and clinical relevance of chromosomal abnormalities in individuals referred for infertility, single miscarriage, or recurrent pregnancy loss (RPL). Materials and methods This large retrospective cytogenetic study analyzed 10,285 individuals referred for infertility, single miscarriage, or recurrent pregnancy loss over a five-year period. Conventional G-banded karyotyping was performed in accordance with International System for Human Cytogenomic Nomenclature (ISCN) 2025 guidelines. Chromosomal abnormalities were classified as numerical or structural, with variants further categorized by specific chromosome involvement. Data on sex distribution and abnormality patterns were summarized to identify trends and clinically significant associations. Results Among the 10,285 individuals evaluated, cytogenetic abnormalities were identified in 980 cases, representing 9.5% of the study population. The cohort demonstrated a largely balanced sex distribution, with 46,XX karyotypes observed in 5,380 cases (52.3%) and 46,XY karyotypes in 4,857 cases (47.2%). Analysis of abnormal karyotypes revealed that chromosomal variants were the most frequent finding, accounting for 514 cases (52.4%), followed by variant inversions in 94 cases (9.6%). Structural chromosomal rearrangements were commonly observed and included reciprocal translocations in 120 cases (12.2%) and Robertsonian translocations in 33 cases (3.4%), involving multiple autosomes and sex chromosomes. Sex chromosome abnormalities comprised a notable subset, with Klinefelter syndrome identified in 53 cases (5.4%), Y-chromosome inversions in 36 cases (3.7%), mosaic karyotypes in 38 cases (3.9%), isochromosome X in 18 cases (1.8%), and additional X chromosomes in 12 cases (1.2%). Other abnormalities such as derivative chromosomes (24 cases, 2.4%), deletions (13 cases, 1.3%), autosomal inversions (14 cases, 1.4%), marker chromosomes (3 cases, 0.3%), and rare duplications or insertions (one case each, 0.1%) were observed less frequently, highlighting the broad spectrum of cytogenetic abnormalities associated with infertility and recurrent pregnancy loss. Conclusion This study demonstrates that chromosomal variants and structural rearrangements constitute the majority of cytogenetic abnormalities in individuals with infertility or recurrent pregnancy loss. Although clinically significant numerical and complex structural abnormalities were less frequent, they confer substantial reproductive risk through mechanisms affecting gametogenesis, chromosomal segregation, and embryonic viability.

The prevalence, incidence, and associated factors of liver disease (LD) in Turner syndrome (TS) remain uncertain. A meta-analysis was performed to quantify LD burden in TS. Four electronic databases were searched through June 2025 for observational studies involving karyotype-confirmed individuals with TS. LD was defined by raised serum liver enzymes (RLE), International Classification of Diseases codes, imaging, or histology. Pooled prevalence, incidence, and odds ratios (OR) with 95% confidence intervals (CI) were calculated. Forty studies from 19 countries with aggregate data on 9728 young TS individuals (median age 25.5 years, IQR 16.8-30.7) were included. Prevalences of RLE, steatotic LD (SLD), and significant/advanced liver fibrosis were 26.9% (95% CI 19.7-35.6), 22.3% (9.9-42.9), and 12.2% (2.6-41.7), respectively. Incidence of RLE was 16.7 per 1000 person-years (7.6-36.8). Compared to age-matched healthy controls, TS individuals had higher odds of RLE (OR 3.96 [95% CI 1.45-10.84]), SLD (OR 4.03 [1.86-8.70]), and significant/advanced fibrosis (OR 5.74 [2.99-11.01]). Compared to X monosomy, isochromosome Xq conferred a higher risk of RLE (OR 1.55 [1.15-2.10]), while mosaicism without structural abnormalities was protective (OR 0.54 [0.32-0.89]). Ring X or Y chromosome material carried risks like X monosomy. Hormone replacement therapy was not associated with an increased risk of RLE (OR 1.10 [0.79-1.53]). Liver disease is common in individuals with TS, with a 4-6 times higher risk than age-matched healthy females. X chromosome abnormalities are more strongly associated with an increased liver disease risk than hypogonadism.

Turner syndrome (TS) is a sex chromosome disorder affecting phenotypic females who have one intact X chromosome and a completely or partially missing second sex chromosome. It was first described approximately a century ago by Seresevskij, Ullrich and Turner. However, the cytogenetic basis of TS was only reported by Ford in 1959 following Tjio and Levan's optimisation of chromosome visualisation. TS karyotypes include classic monosomy X (40%-50%); monosomy X mosaicism (3%-25%); isochromosome X (10%-18%); ring X (10%-16%); mosaicism for monosomy X and a normal or structurally abnormal Y chromosome (6%-12%); deletion Xp (< 5%) and unbalanced X-autosome translocation (< 2%). While parental age does not affect the complete loss of one X chromosome, the paternal X chromosome is absent in three-quarters of patients with TS. Clinically, detecting the parental origin of the remaining X chromosome is not currently useful in routine TS care. Recurrence risk is low for phenotypically normal parents with a child diagnosed with TS. Pregnancy loss is the outcome for the majority (~99%) of TS cases; however, prenatal ultrasound findings for foetuses with TS may include abnormalities like cystic hygroma and hydrops. Postnatal phenotype for patients with TS includes short stature, delayed puberty, ovarian dysgenesis, hypergonadotropic hypogonadism, infertility, cardiac defects, endocrine, metabolic and autoimmune disorders. This review aims to outline clinical indications for testing, describe test methodologies, provide genetic test result examples that highlight complex TS karyotype diagnoses, summarise clinical management options and discuss the phenomenon of 'normal' sex chromosome loss with advancing age.

Variant Klinefelter syndrome (VKS) presents with variable phenotypes, caused by the involvement of different genetic abnormalities leading to delays in confirming diagnosis and, therefore, delays in early management of this disorder. We describe a male with VKS and trisomy Xq resulting from an isochromosome X(i(Xq10)). He had characteristics of classical KS such as azoospermia, hypergonadotropic hypogonadism with elevated follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, and bilateral atrophic testes. He achieved a normal intelligence level. However, we observed a normal stature appropriate for his height. There was no history of developmental delays or learning problems during childhood. His karyotype was found to be 47,X,i(X)(q10),Y, which indicates that extra copies of the long arm of Xq (trisomy Xq) have phenotypic expression. In conclusion, Trisomy Xq does not affect stature and neurological development and does not express classical phenotypes during early childhood. Hence, the cytogenetic screening of sex chromosomal abnormalities is important in cases of hypergonadotropic hypogonadism and testicle abnormality, which can help in appropriate genetic counseling.

Turner syndrome (TS) presents with multiple karyotypes, including 45,X monosomy and variants such as isochromosomes and mosaicism, and is characterized by several co-morbidities, including metabolic conditions and autoimmunity. Here, we investigated the genomic landscapes across a range of karyotypes. We show that TS have a common autosomal methylome and transcriptome, despite distinct karyotypic variations. All TS individuals lacked the X chromosome p-arm, and XIST expression from the q-arm did not affect the autosomal transcriptome or methylome, highlighting the critical role of the missing p-arm with its pseudoautosomal region 1. Furthermore, we show increased levels of neutrophils and increased neutrophil activation. The increase in neutrophils was linked to TS clinical traits and to increased expression of the X-Y homologous gene TBL1X, suggesting a genetic basis, which may lead to neutrophil-driven inflammatory stress in TS. Identifying TS individuals with increased neutrophil activation could potentially mitigate the progression towards more severe metabolic issues.