Indian Journal of Genetics and Molecular Research

Background: High-grade serous ovarian carcinoma (HGSOC) is frequently associated with homologous recombination repair (HRR) deficiency due to BRCA1/2 mutations. Recognition of characteristic histopathological patterns in BRCA-mutated and HRD-positive tumours has diagnostic and therapeutic relevance. Objective: To identify distinctive histomorphological features associated with BRCA mutated and/or HRD-positive HGSOC and correlate them with clinicopathological parameters. Methods: A retrospective observational study was conducted. Of the 333 histologically confirmed HGSOC cases (2018–2024), 48 underwent BRCA testing, and 9 had concurrent HRD analysis. Archival haematoxylin and eosin (H&E) slides were reviewed for SET morphology (solid, pseudo-endometrioid, transitional), necrosis, nuclear pleomorphism, mitotic index, and tumour infiltrating lymphocytes (TILs). Clinical and molecular data were retrieved, and statistical associations were analysed using Chi-square and Fisher’s exact tests. Results: Among 48 tested cases, BRCA1 mutations were identified in 25% and BRCA2 in 2.1%; 33.3% (16/48) were BRCA / HRD positive. BRCA/HRD-positive tumours showed significantly higher frequencies of necrosis, high mitotic activity, lymphovascular invasion, and SET pattern. The odds of BRCA/HRD positivity were approximately 13–17 times higher in tumours exhibiting SET morphology. TILs were more frequent but not statistically significant.

Hemoglobinopathies, characterized by abnormal hemoglobin structure or production, are primarily caused by mutations in the HBB gene located on chromosome 11. While the contribution of nuclear gene mutations is welldocumented, the involvement of mitochondrial DNA (mtDNA) variations, particularly within the D-loop region, remains underexplored in antenatal carriers. This study screened 320 blood samples from pregnant women to identify the antenatal carriers for hemoglobinopathy by assessing abnormal hemoglobin levels using hemoglobin electrophoresis, and investigated the association between HBB mutations and mitochondrial D-loop variations in 18 hemoglobinopathy carriers using Sanger sequencing. This analysis identified IVS1-5G>C as the most prevalent HBB mutation (83.3%), followed by c.6 A>T and c.26 G>A. Four novel heteroplasmic variations in the Mitochondrial D-loop were identified at positions 716A>C, 747A>T, 749G>C, and 786G>C. The variation at position 786 was associated with the c26 mutations (HbE variant), while the others were linked to the IVS1-5 mutation (Beta thalassemia trait, HbA2). These novel D-loop variations, absent in current GenBank records, may serve as potential genetic markers influencing disease susceptibility and clinical phenotype in antenatal hemoglobinopathy carriers. Our findings indicate that mitochondrial D-loop variations could play a pivotal role in the genetic architecture of hemoglobinopathy in antenatal carriers, potentially influencing disease expression and providing insights into genetic counseling. Further research is needed to clarify the interplay between nuclear and mitochondrial genomes and their implications for antenatal screening and management strategies in hemoglobinopathy and related genetic disorders.

Cytogenetics is the study of structure and behavior of chromosome at a macroscopic level. Various cytogenetic techniques can detect different numerical such as aneuploidies and abnormalities in chromosomal structure such as Duplication, Deletion, Translocation, Inversion, Insertion and Copy Number Variations (CNVs) etc. Scientific and technical advancements from conventional cytogenetics to molecular cytogenetics in the field of medical genetics have brought improvements in the resolution of chromosome analysis facilitating a deeper understanding of chromosomes, structurally and functionally. Shift in cytogenetics to chromosomics has helped in understanding the influence of three-dimensional dynamic structure and function of chromosomes on gene expression and genome evolution by integrating cytogenetics with genomics and cell biology. This evolution in cytogenetics has made the possibility of not only postnatal diagnosis of chromosomal abnormalities but is also responsible for the advent of prenatal chromosomal disorders’ diagnosis and genetic counseling in clinical medicine. Now it is our aim to make aware our patients about these available advanced tests and make available these tests to our patients at low cost. This incredible journey from symptomatic disease to conventional karyotype to molecular cytogenetic to chromosomics (genotype) should be continued in the future for the futuristic genetic evolution. This review article talks over the evolution and advancements in cytogenetic techniques covering a brief overview of conventional Karyotyping and FISH and discussing in detail about molecular cytogenetics advanced techniques like Multiple Ligation Dependent Probe Amplification (MLPA), Quantitative Flourescent-Polymerase Chain Reaction (QFPCR), Chromosomal microarray and Optical Genome mapping.

Background: Ovarian cancer (OC) is the most common gynaecological malignancy among women worldwide, with a significant disease burden in India (incidence: 6.6%; mortality: 7.4% per 100,000). Epithelial ovarian cancer (EOC) is the predominant subtype, typically diagnosed at an advanced stage. Standard treatment involves cytoreductive surgery followed by adjuvant chemotherapy with a taxane platinum combination, which initially shows favourable clinical outcomes. However, the majority of patients relapse within 12–18 months due to the development of chemoresistance. Methods: The cytotoxic effects of CDDP, PJ34, and BSO were evaluated individually and in combination using MTT assays in ovarian cancer cell lines (KURAMOCHI, OVSAHO, and IGROV1). Cell cycle and apoptosis were analysed by flow cytometry. Gene expression of PARP-1 and GCS in peripheral blood (PB) and ascitic fluid of newly diagnosed and relapsed ovarian cancer patients was assessed using QRT-PCR, and GSH levels were quantified using ELISA. Results: CDDP showed greater cytotoxicity than PJ34 and BSO, with the IGROV1 cell line exhibiting the highest sensitivity. Combination treatment with CDDP + PJ34 + BSO demonstrated a synergistic effect, significantly reducing cell viability and enhancing cell death compared to monotherapies. Co-treatment induced S-phase arrest and promoted apoptosis. GCS MRNA was significantly upregulated in PB and ascitic fluid of newly diagnosed patients, whereas PARP-1 expression remained unchanged. Elevated GSH levels in PB and reduced levels in ascitic fluid correlated with GCS activity, suggesting a redox imbalance contributing to chemoresistance.

Background: A non-consanguineous couple approached us with a history of 6 first trimester unexplained miscarriages (4 natural conceptions, 1 intrauterine insemination (IUI) cycle conception and 1 in-vitro fertilization (IVF) cycle conception. No genetic testing was carried out for abortuses. Clinical data: Couple karyotyping was normal. Couple carrier screening revealed that the husband was heterozygous for a variants c.3829A>G in RELN gene exon 27 and the wife was compound heterozygous for 2 variant c.4739C>G exon 32 and c.5156C>T exon 34 in RELN gene with autosomal recessive (AR) inheritance, responsible for Lissencephaly 2. All were reported as variants of uncertain significance (VUS). As the wife was unaffected, both variants must have been in cis. The husband was also heterozygous for AR SMN1 variant. No preimplantation genetic testing (PGT) was offered previously. Investigation: The couple underwent 3 IVF cycles with PGT for chromosomal aneuploidy (PGT-A) followed by PGT for monogenic disorder (PGT-M) for RELN gene variants. Results: Of 9 blastocyst embryos tested, only one euploid heterozygous embryo with a single variant was available for implantation. Frozen embryo transfer led to a singleton pregnancy and birth of a healthy boy Discussion: As there was no family history of lissencephaly, the findings of RELN variants on carrier screening were not further evaluated. No possible correlation was made with RELN variants or presence of aneuploidy in the embryos and first trimester recurrent pregnancy loss. Hence PGT-M was not offered previously for VUS neither PGT-A. However, as the classification of VUS may change to pathogenic in future after availability of sufficient data, we offered PGT. In this case as the couple had 3 VUS in RELN gene, a compound heterozygous future child could be affected with cobblestone lissencephaly. Hence PGT-M was important in this case. Due to the history of failed IUI-IVF cycles and 6 miscarriages, PGT-A was also very important to use euploid embryos for successful implantation and to reduce miscarriage risk due to aneuploidy. Recent literature shows that RELN gene variant may impair embryonic microenvironment homeostasis leading to early miscarriages and the possible cause of miscarriages. This shows the importance of genetic counselling to offer specific investigations, to deliver a healthy child to couples.