Molecular Genetic Characterization Research Articles

TMIC-10. GENETIC LANDSCAPE OF BRAIN METASTASIS IN TRIPLE-NEGATIVE-BREAST CANCER: COMPARISON OF PAIRED PRIMARY AND METASTATIC TUMOR USING SPATIAL TRANSCRIPTOMIC ANALYSIS

Abstract The survival rate of individuals diagnosed with breast cancer has shown improvement over time, primarily attributed to advancements in early detection methods and the implementation of proactive treatment strategies. However, it is concerning that the incidence of breast cancer continues to rise, thereby leading to a corresponding increase in mortality rates among female breast cancer patients. Among these, the presence of brain metastasis is associated with a worse prognosis in individuals with breast cancer. Notably, triple-negative breast cancer exhibits a heightened propensity for the development of brain metastasis. Furthermore, there has been a notable rise in the duration of breast cancer survival, leading to a concomitant increase in the occurrence of metastatic cancer throughout the course of the disease. Presently, a greater number of patients are experiencing brain metastases, surpassing the figures reported in current statistical data. In instances of metastatic cancer, a distinct microenvironment that is particular to the tumor is formed in a distant location. The comprehension of the molecular genetic and immunological mechanisms involved in the several phases of brain metastasis, including tumor cell invasion, engraftment, and proliferation, has significant importance in the context of patient treatment and prognosis prediction. However, it is worth noting that a well-defined scientific foundation in this area is currently absent. The objective of this study was to analyze the molecular genetic characteristics of triple-negative breast cancer primary tumors and brain metastasis tumors. This was achieved by utilizing spatial transcriptome analysis technology to compare the differences in genetic profiles between the tumor cells and the surrounding tumor microenvironment. The findings of this study allowed for a comprehensive comparison of the tumor microenvironment at each site. In order to validate alterations in gene expression of various constituents and elucidate the mechanisms behind metastasis, it is imperative to conduct spatial confirmation.

Genetic analysis of a blood donor with combined FUT1 and ABO dual blood group gene variants resulting in para-Bombay and A2 subtype blood types and a literature review

To investigate the serological and molecular genetic characteristics of a voluntary blood donor with combined FUT1 and ABO blood group gene variants causing para-Bombay and A2 subtype, and to review relevant literature on para-Bombay blood types carrying alleles such as FUT101W.37 and FUT101W.23. A blood donor with para-Bombay and A2 subtype who participated in voluntary blood donation at the Dongguan Blood Center in August 2023 was selected as the study subject. Serological tests were performed to identify the ABO blood group, Lewis blood group antigens, and unexpected serum antibodies in the donor. Adsorption-elution test was conducted to detect trace antibodies in the blood donor's plasma to trace the A, B and H antigens on the red blood cell surface. Sanger sequencing was carried out to analyze the sequences of the FUT1 and ABO genes. Using keywords such as "para-Bombay" "FUT1*01W.37" and "FUT1*01W.23" both in Chinese and English, relevant literature on para-Bombay blood type subjects carrying FUT1*01W.37 and FUT1*01W.23 alleles was retrieved from the CNKI, Wanfang Data Knowledge Service Platform, and PubMed databases, and the retrieval time was set as from the establishment of database to December 2022. This study has been approved by the Ethics Committee of Dongguan Blood Center (No. 2022005), and informed consent of blood donation was obtained from the blood donor. Serological testing of the blood donor revealed inconsistent results between forward and reverse ABO blood typing, negative H antigen on the red blood cell surface, Le(a-b+) secretor type for Lewis blood group, and unexpected anti-H antibodies in the plasma, indicating a suspected para-Bombay type. Absorption-elution test suggested the blood type of the blood donor to be para-Bombay and A subtype. Sanger sequencing showed that the donor has harbored homozygous FUT1*(c.35T+c.803A)/(c.35T+c.803A) variant, with the FUT1*(c.35T+c.803A) allele containing a dual nucleotide variant unrecorded by the International Society of Blood Transfusion (ISBT) FUT1 gene variant database, which was similar to the weakly functional allele of FUT101W. 37(c.803G>A) as recorded by the ISBT database. The ABO genotype was heterozygous ABOA2.05/O.01.02. Combining the results of serological and genetic testing, the blood type of the blood donor was determined to be para-Bombay and A2 subtypes. Literature review has identified a pregnant women from Qingdao carrying the FUT1*01W.37 allele and 2 individuals carrying a heterozygous FUT1*01W.23 allele. This study has discovered a blood donor with coexisting para-Bombay and ABO subtype blood groups. Based on the characteristics of red blood cell surface antigens, the FUT1*01W.37 as classified as an FUT1 null allele.

Primary intracranial sarcoma associated with DICER1 mutant: a case report and preclinical investigation.

Primary intracranial sarcoma (PIS) is a rare and aggressive pediatric brain tumor, which is partially associated with DICER1 mutant. Although the molecular genetic characteristics of this tumor have previously been investigated, novel therapeutic targets remain unclear. Further, the lack of faithful preclinical models has hampered the development of novel therapeutic strategies. Herein, we describe a pediatric case of PIS with DICER1 mutant and describe the development of the first novel patient-derived xenograft (PDX) model of this rare tumor. Somatic genomic profiling of the tumor revealed mutations in DICER1, TP53, and ATRX. Germline analysis further revealed a pathogenic variant of DICER1, significant for the diagnosis and management of hereditary tumor predisposition syndrome. Overall, we demonstrated that the PDX model faithfully retained the phenotype and genotype of the patient's tumor, as well as the DNA methylation profile. Through high-throughput drug screening using PDX tumor cells, we found that activation of the retinoic acid receptor (RAR) signaling pathway reduced tumor cell viability. These findings indicate that the RAR signaling pathway is a potential therapeutic target for PIS in DICER1 mutant.

TP53 Mutation Status in Myelodysplastic Neoplasm and Acute Myeloid Leukemia: Impact of Reclassification Based on the 5th WHO and International Consensus Classification Criteria: A Korean Multicenter Study.

TP53 mutations are associated with poor prognosis in myelodysplastic neoplasm (MDS) and AML. The updated 5th WHO classification and International Consensus Classification (ICC) categorize TP53-mutated MDS and AML as unique entities. We conducted a multicenter study in Korea to investigate the characteristics of TP53-mutated MDS and AML, focusing on diagnostic aspects based on updated classifications. This study included patients aged ≥ 18 yrs who were diagnosed as having MDS (N=1,244) or AML (N=2,115) at six institutions. The results of bone marrow examination, cytogenetic studies, and targeted next-generation sequencing, including TP53, were collected and analyzed. TP53 mutations were detected in 9.3% and 9.2% of patients with MDS and AML, respectively. Missense mutation was the most common, with hotspot codons R248/R273/G245/Y220/R175/C238 accounting for 25.4% of TP53 mutations. Ten percent of patients had multiple TP53 mutations, and 78.4% had a complex karyotype. The median variant allele frequency (VAF) of TP53 mutations was 41.5%, with a notable difference according to the presence of a complex karyotype. According to the 5th WHO classification and ICC, the multi-hit TP53 mutation criteria were met in 58.6% and 75% of MDS patients, respectively, and the primary determinants were a TP53 VAF >50% for the 5th WHO classification and the presence of a complex karyotype for the ICC. Collectively, we elucidated the molecular genetic characteristics of patients with TP53-mutated MDS and AML, highlighting key factors in applying TP53 mutation-related criteria in updated classifications, which will aid in establishing diagnostic strategies.

Molecular epidemiology and genetic characterization of hepatitis B virus in two major provinces of Pakistan.

Hepatitis B virus (HBV) infection is a major public health issue and is responsible for considerable morbidity and mortality globally. In Pakistan, the prevalence of chronic HBV infection varies from 2% to 4%, with an estimated exposure rate of approximately 34%. The major objective of this study was to determine the prevalence of HBV genotypes and the pattern of escape mutations in the HBV S gene in two major provinces of Pakistan: Punjab and Khyber Pakhtunkhwa. A total of 146 serum/plasma samples collected from hepatitis B patients were sequenced by the Sanger method. Phylogenetic analysis indicated the intermixed circulation of closely related strains of HBV genotype D and subgenotypes HBV/D1, HBV/D2, and HBV/A2 in both provinces, and various escape mutations (Y100C, P120S/T, G119R, C121S/Y, R122K, T126I, A128V, Q129H/R, G130R, T131N/I, M133T/I, Y134N, C137W, S143L, and D144E) were identified. These findings provide important insights into the current prevalence of HBV genotypes in Pakistan and will help in the establishment of more-efficient disease interventions and patient management strategies.

Clinical Outcomes and Molecular Characteristics of Bacteroides fragilis Infections.

Bacteroides fragilis is the most common opportunistic anaerobic pathogen. In the absence of appropriate antimicrobial therapy, mortality rates associated with B. fragilis group infections can reach as high as 50%. Therefore, we aimed to elucidate the clinical characteristics and outcomes of B. fragilis infections and the molecular genetic characteristics of B. fragilis isolates. Forty B. fragilis clinical isolates were collected at Hanyang University Hospital between January 2022 and December 2023. Antimicrobial susceptibility was tested using the agar dilution method. Whole-genome sequencing was conducted using the Illumina platform (Illumina, San Diego, CA, USA). Various multilocus sequence types of B. fragilis were identified, including ST149 (N=4), ST11 (N=4), ST1 (N=3), ST21 (N=2), and ST157 (N=1). The insertion sequence (IS) IS1187, located upstream of cfiA, was associated with high-level carbapenem resistance in the ST157 isolate. B. fragilis toxin genes (bft ) were identified in 30% of isolates. The most common comorbidities were diabetes mellitus (26.5%) and non-metastatic cancer (23.5%). Five patients (14.7%) died within 30 days, and two (5.9%) deaths were directly attributable to B. fragilis infection. The emergence of high-level MIC carbapenem-resistant B. fragilis ST157 has led to caution in the presence of B. fragilis infections.

Molecular Genetic Factors of Risk Stratification of Lymph Node Metastasis in Endometrial Carcinoma.

According to epidemiological studies, endometrial carcinoma is one of the most frequently diagnosed malignancies of the female reproductive system, with an increasing incidence. Currently, the risk stratification of this neoplasm takes into account the stage, degree of tumor differentiation, histological type and depth of myometrial invasion. Since the publication of the last International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial cancer in 2009, numerous reports have appeared on the molecular characteristics of different types of endometrial carcinoma. Taking this into account, the FIGO Committee determined in 2023 that changes and updates to the staging system are justified to reflect new information about this tumor. Due to the high prevalence of the disease and mortality from endometrial cancer, an in-depth study of the molecular genetic characteristics of tumor cells is relevant; the results of such studies can be used to improve the efficiency of diagnosis, assess the risk of metastasis and prognosis of the disease. Lymph node assessment is crucial for the choice of treatment strategy for endometrial cancer, since metastatic lymph node involvement is one of the main factors affecting prognosis. At the same time, the criteria for the appropriateness of lymphadenectomy in low-differentiated malignant tumors are not clearly defined. Various molecular methods have been proposed to assess the status of lymph nodes; candidate genes are being studied as potential diagnostic biomarkers, as well as microRNA. The aim of the study was to analyze the literature data on numerous studies of molecular risk factors for progression in endometrioid carcinoma, as well as to preserve the most important marker changes in relation to the prognostic development of this disease. A literature review was conducted using data from the electronic databases PubMed, Google Scholar, and Wiley Cochrane Library for the period from 2018 to 2023 using the specific keywords. The current scientific genetic studies on metastasis and prognostic factors in uterine cancer were analyzed, and a systematization of the reviewed data from the modern literature was done. To select the most effective treatment - intraoperative, adjuvant or combination therapy, minimize postoperative risks of lymphadenectomy and clearly predict the results - further study of the molecular genetic features of endometrial cancer is necessary.

Metanephric tumors in children and adolescents: clinical, morphological and molecular genetic characteristics

Metanephric tumors in children and adolescents: clinical, morphological and molecular genetic characteristics

Pilomatrix-like breast carcinoma: A mammary analog of pilomatrix-like high-grade endometrioid carcinoma (PiMHEC).

To describe what is, to our knowledge, the first recognized case of a triple-negative breast carcinoma (TNBC) with a PiMHEC-like phenotype.Pilomatrix-like high-grade endometrioid carcinoma (PiMHEC) is a high-grade carcinoma with divergent differentiation resembling cutaneous pilomatrix carcinoma that was recently described in the endometrium and ovary. For reference, pertinent features of PiMHEC include (1)high-grade basaloid to squamoidmorphology withthe presence of ghost cells; (2) only focal p63 and/or p40 expression despite a squamoid appearance; (3) CTNNB1 mutation, accompanied by diffusely aberrant β-catenin expression and LEF1 and/or CDX2 expression; and (4) loss of site-specific markers (ie, PAX8, ER). Here we report the histologic, immunophenotypic and molecular genetic features ofa case of a triple-negative breast carcinoma (TNBC) with a PiMHEC-like phenotype. The tumor developed immediately adjacent to a HER2+, androgen receptor (AR)+, GATA3+ conventional grade 3 invasive ductal carcinoma (IDC) with only membranous β-catenin expression. The PiMHEC-like component had all of the above-noted morphologic and immunophenotypic features of endometrial PiMHEC but with loss of GATA3 and AR rather than PAX8 and ER.Molecular analysis performed on both tumor components demonstrated a shared TP53 point mutation and an exon 3 CTNNB1 mutation restricted to the PiMHEC-like component, implying a clonal relationship with secondary acquisition of CTNNB1. Following neoadjuvant chemotherapy, the HER2+ conventional component had completely resolved, but the PiMHEC-like component had very little response. This case demonstrates that a PiMHEC-like phenotype may be seen as a form of TNBC that can develop from conventional IDC, with loss of site-specific biomarkers, acquisition of CTNNB1 mutation, and resistance to conventional chemotherapy.

Mechanisms of drug resistance to neoadjuvant chemotherapy in breast cancer

Aim. Тo study the molecular genetic characteristics of the tumor microenvironment and the mechanisms of cell death in resistant locally advanced breast cancer.Materials and methods. The study included 48 patients with breast cancer T2–4N0–3M0–1 (mean age 55.6 ± 9.8 years), and 29 patients of comparable age with breast fibroadenoma. According to the design of the study, patients were divided into groups: Group 1 included women with breast cancer resistant to neoadjuvant chemotherapy (n = 23), Group 2 – with breast cancer and a complete response to neoadjuvant chemotherapy (n = 25), control Group – with fibroadenoma (n = 29). The expression of markers CD4+, CD8+, CD20+, CD68+, tumor necrosis factor α (TNF-α), vascular endothelial growth factor A (VEGF A), Ang-2, matrix metalloproteinase 12 (MMP-12), inducible nitric oxide synthase (iNOS), bcl-2, p53, CD95 was assessed using immunohistochemistry.Results. When phenotyping immune cells, the following differences were obtained: in the tumor tissue of patients in Group 1, a significant decrease in the number of cytotoxic CD8+ cells was noted compared to Group 2 (p = 0.001) and control (p = 0.032). In Group 2, a significant increase in the number of CD68+ cells was revealed in relation to Group 1 (p = 0.027). The cytokine profile of the tumor microenvironment in Group 1 is characterized by statistically significant overexpression of TNF-α compared to Group 2 (p >0.001) and the control Group (p = 0.01). With regard to apoptotic factors, noteworthy is the significant decrease in the expression of bcl-2 and p53 in Group 1 compared to Group 2 (p = 0.001 and p = 0.02 accordingly).Conclusion. The presented results can serve as the basis for the creation of diagnostic algorithms that have predictive value regarding the effectiveness of NCT, and also to help identify new targets to justify the use of combined breast cancer treatments in the early stage.

Clinicopathological and molecular characteristics of microsecretory adenocarcinoma in salivary gland

Objective: To investigate the clinicopathological, immunohistochemical, and molecular genetic characteristics of microsecretory adenocarcinoma (MSA) of the salivary gland, and to improve the understanding of this rare tumor. Methods: Cases originally diagnosed as MSA at the Department of Oral Pathology, the Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine were retrospectively collected. The cases of polymorphous adenocarcinoma and adenocarcinoma, not otherwise specified from January 2000 to January 2020 were reviewed to identify potential misdiagnosed MSA cases. Clinicopathological analysis and follow-up of all confirmed MSA cases were performed, and relevant literature was reviewed. Results: A total of 4 MSA cases were identified, including 2 screened from the polymorphous adenocarcinoma cohort. Of the 4 MSA patients, 3 were male and 1 was female, with an average age of 53 years (range, 37-67 years). Three cases occurred in the palate, and one in the buccal region. The clinical manifestation was usually a slow-growing painless mass. Tumors were generally small, with a maximum diameter ranging from 0.7 to 1.8 cm (average, 1.2 cm). Microscopically, the tumor was unencapsulated and showed an infiltrative growth pattern. The tumor cells appeared small in size and showed bland, cubic and flattened cytological features, forming microcystic lumens and glandular tubes. Significant basophilic secretions were seen in the lumens. Between the tumor nests there was fibro-myxoid stroma. Immunohistochemistry showed diffusely or partially positive staining for cytokeratin 7, S-100, SOX-10, p63 and vimentin and negative staining for p40, mammaglobin, and calponin. The proliferation index of Ki-67 was relatively low (1%-3%). Four MSA cases all harbored SS18 gene rearrangement as shown by fluorescence in situ hybridization (FISH), including 2 cases with MEF2C::SS18 fusion gene through RNA-targeted next generation sequencing. All 4 patients underwent surgical resection without any adjuvant treatments. Three patients were followed up for a period of 2 to 203 months. No tumor recurrence, metastasis, or disease-related death was found. Conclusions: Salivary gland MSA is a novel and rare low-grade carcinoma with unique and consistent histological morphology, immunophenotype, and molecular changes. Immunohistochemical staining and SS18 break apart FISH are useful for the diagnosis of the tumor with atypical morphology and high-grade transformation.

12279 Molecular Strategy And Genetic Characterization Of A Large Cohort Of Pediatric Patients With Hereditary Hypophosphatemic Rickets: Advantages Of Next Generation Sequencing

Abstract Disclosure: N. Perez Garrido: None. P. Ramirez: None. G.L. Viterbo: None. M. del Pino: None. S. Abbate: None. N.I. Saraco: None. F. Tesan: None. M. Ciaccio: None. V. Fano: None. A. Belgorosky: None. R. Marino: None. Background: Hereditary hypophosphatemic rickets (HHR) is a group of rare disorders characterized by renal phosphate wasting and impairment of vitamin D metabolism. Different genetic defects can cause HHR, although they share similar clinical, radiological and biochemical features. Dominant X-linked HR (XLHR) is the most frequent form (1/ 20,000) caused by inactivating variants in PHEX gene. As affected individuals present with a broad phenotypic spectrum next generation sequencing (NGS) represent a useful tool for molecular diagnosis characterization. Aim: To report a molecular strategy and genetic characterization of a large cohort of pediatric patients with HHR followed in a single tertiary institution. Patients and Methods: We analyzed 77 affected patients from 60 non related families (and 58 parents) sent to our laboratory for molecular genetic testing under suspicion of HHR based on clinical, radiological and laboratory studies.In patients without hypercalciuria, Sanger sequencing of PHEX gene was initially performed. In female cases in which no alteration was detected, MLPA analysis was used to detect copy number variations. A group of patients with no proven variations in PHEX gene and those with hypercalciuria were analyzed using a NGS custom panel including 14 related genes. Results: Of the total 60 non related cases a pathogenic variant was found in 52 (87%). Regarding PHEX gene analysis, a pathogenic variant was found in 48/60 (80%), 27 were sporadic and 21 familial cases. Forty-one different pathogenic variants were found (5 gross deletions, 13 nonsense, 9 frameshift, 5 splice-site and 9 missense) distributed throughout the gene with higher prevalence from exon 15 to 22. 18/41 (44%) of variants were novel. RNA analysis was performed in 2 novel splice variants (c.849G>A-p.Glu283Glu and c.1586+6T>A) in which an abnormal splicing was confirmed.We found a pathogenic variant in 5/9 cases analyzed by NGS. Three of them in SLC34A3 gene (2 homozygous, 1 compound heterozygous), 1 in ENPP1 gene (compound heterozygous) and 1 in PHEX gene non-detected by Sanger sequencing. Discussion: This molecular strategy, along with a careful clinical and biochemical selection of patients, allowed us to perform genetic diagnosis in 87 % of non-related families. This study reports 21 novel pathogenic variants and it shows the greatest genetic characterization in pediatric HHR patients in Argentine population. The results obtained confirmed that PHEX is the most responsible gene for HHR phenotype, as previously described. By NGS, less common forms of rickets could be detected. Among them, the most frequent was HHR with hypercalciuria due to recessive mutations in SLC34A3 gene. NGS studies represent a useful tool, especially in those complex cases, to reach an accurate diagnosis, and they contribute to improve long term follow up of patients and genetic counseling. Presentation: 6/2/2024

Clinicopathological and molecular genetic insights into EBV-positive inflammatory follicular dendritic cell sarcoma

Epstein-Barr virus (EBV)-positive inflammatory follicular dendritic cell (FDC) sarcoma (EBV + IFDCS) is a rare entity, and its histopathological characteristics have not been fully described. This study aimed to investigate the clinical characteristics, pathological features, and molecular genetic profiles of EBV + IFDCS to improve our understanding of these lesions. A total of 12 EBV + IFDCS specimens were obtained from patients in our pathology diagnostic center. The clinical data, morphology, immunohistochemistry, in situ hybridization, and high-throughput DNA-targeted sequencing data were collected, and follow-up data were analyzed. These data were compared with those of 6 patients with traditional FDCS. The patients with EBV + IFDCS ranged from 21 to 84 years old, with a mean age of 52.3 years and a male-to-female ratio of 1:5. At the last follow-up, all patients were alive, with 2 experiencing recurrence and metastasis. In these cases, four were classified as the classical subtype, four as the angiomatoid/sclerosing subtype, and four as the lymphoma-like subtype, with two cases also exhibiting epithelioid granulomas. All patients exhibited heterogeneous expression of follicular dendritic cell markers (CD21, CD23, CD35, and CXCL13) alongside the fibroblast marker SMA, with significantly higher expressions of IgG4, EBER, and SMA in EBV + IFDCS patients compared to FDCS patients (P < 0.05). Conversely, SSTR2, EGFR, and STAT3 expression were significantly lower in the EBV + IFDCS group (P < 0.05). The average value of EBER was significantly higher in the classical subtype group (P = 0.022). Among the four cases of EBV + IFDCS analyzed for molecular genetic features, one patient exhibited germline mutations in the CDKN1C, PDGFRA, MSH2, FANCG, MLH1, ALK, and RUNX1 genes; three exhibited simultaneous SNP variations in the MTHFR gene; and two exhibited simultaneous SNP variations in the NQO1 gene. We conducted KEGG pathway analysis on the mutant genes, revealing significant enrichment in the cAMP signaling pathway, which plays a crucial role in tumor development. Survival analysis demonstrated that the median PFS rates were not reached (NR) for EBV + IFDCS patients, compared to 5 months (HR = 7.76) for FDCS patients. The 3-year PFS rates were 66.67% and 16.67%, respectively. Compared with the FDCS group, EBV + IFDCS patients had a significantly longer median PFS time (p < 0.05). In conclusion, EBV + IFDCS represents a group of tumors with unique clinical, morphological, immunological, prognostic, and molecular cytogenetic characteristics.

New insights into hematopoietic cell transplantation in ALL: Who should be transplanted, when, and how

Advancements in multi-agent chemotherapy through clinical trials conducted by multi-institutional collaborative groups worldwide, along with risk stratification using molecular genetic features and treatment responses, including minimal residual disease, have significantly improved outcomes for children and adolescents with acute lymphoblastic leukemia (ALL) over the past half-century. However, for a certain number of high-risk patients, including those with relapsed or refractory disease, for whom existing chemotherapy alone is insufficient for cure, allogeneic hematopoietic cell transplantation (HCT) has provided a potential opportunity for leukemia cure. For these patients, the appropriate selection of donor and stem cell source, conditioning regimen, timing of transplantation, and comprehensive supportive care, including effective graft-versus-host disease prophylaxis, are prerequisites for successful HCT. While HCT from a human leukocyte antigen (HLA)-matched sibling has traditionally been the preferred option, less than 25 % of patients currently have such a donor in developed countries. Consequently, alternative donor HCT options, such as those from matched unrelated donors identified through high-resolution HLA typing, unrelated cord blood donors, and more recently, haploidentical donors using post-transplant cyclophosphamide or TCRαβ+/CD19+ cell-depleted grafts, are providing broader access to HCT for patients lacking matched sibling donors. Nonetheless, HCT carries the risk of various acute and late toxicities. In particular, the use of myeloablative conditioning with total body irradiation, a standard in pediatric ALL, is associated with significant long-term sequelae. As our understanding of the pathophysiology of the disease improves and novel molecular targeted therapies and immunotherapies are developed, the indication for HCT in pediatric ALL is becoming more selective, leading to a gradual decrease in the number of transplants performed. However, further optimization and evolution of allogeneic HCT are needed to both maximize its anti-leukemia effects and minimize transplant-related complications, as there remain cases that undoubtedly require HCT for the cure of leukemia.

Гено-фенотипические особенности муковисцидоза у российских детей из Чеченской и Карачаево-Черкесской Республик

Background: Cystic fibrosis (CF) is an autosomal recessive disease that occurs with a frequency of 1:1,500 to 1:5,000 newborns, according to the World Health Organization. In the Russian Federation, the average incidence of the disease is 1:10,000 newborns. The medical and social significance of this disease is associated with the early disability of patients, the need for long-term treatment and constant follow-up, as well as the heterogeneity of phenotypic manifestations, which in turn requires early diagnosis using molecular genetic methods. The aim of the study: To study the clinical and molecular genetic characteristics of children with CF from the Chechen and Karachay-Cherkess Republics. Materials and methods: The study included 237 patients with a confirmed diagnosis of CF. Molecular genetic diagnostics was performed using the method of mass parallel sequencing using a hybridization target panel that includes the entire CFTR gene. Sequencing was performed on the MiSeq platform. All causal nucleotide variants were validated using Sanger sequencing. Results: The most common amino acid variants of the CFTR gene in patients with CF from the Chechen Republic are: p.Y515* (94 alleles/78.3%), p.E92K (18 alleles/15%). The presence of variants p.Y515* and p.E92K in the heterozygous state in the genotype is more often a favorable prognostic factor for the absence of pancreatic lesion. The main distinctive clinical feature of these patients is the onset of the disease with manifestations of pseudo-Bartter syndrome. The major amino acid variant of the CFTR gene in patients with CF from the Karachay-Cherkess Republic is: p.W1282* (28 alleles/70%). The number of patients with pseudo-Bartter syndrome was 54.5%. In 90% of cases, in patients who are homo- and heterozygous according to p.W1282*, a severe degree of pancreatic insufficiency was noted. Conclusion: Patients with cystic fibrosis from the Chechen and Karachay-Cherkess Republics are a difficult category of patients, despite neonatal screening, and cystic fibrosis therapy developed and implemented. This is partly due to the peculiarities of the phenotype and the unique distribution of alleles and genotypes of the CFTR gene. The high number of homozygous variants of the CFTR gene in patients from the Chechen and Karachay-Cherkess Republics is probably due to monoethnic marital assortativity.

Myelodysplastic syndrome (MDS)/Myeloproliferative neoplasm (MPN) with loss of long arm of chromosome 5 (del 5q): Clinical case and treatment perspectives.

this clinical case report presents a patient diagnosed with a myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN), specifically myelofibrosis with a deletion of the long arm of chromosome 5 (del 5q), an exceedingly rare anomaly in chronic myeloproliferative disorders. We performed a thorough analysis of the patient’s clinical, laboratory, and molecular-genetic characteristics to evaluate their impact on prognosis, treatment decisions, and therapeutic outcomes. After excluding other genetic abnormalities, the patient was treated with lenalidomide and prednisolone, resulting in improved clinical and hematological parameters. These findings are consistent with previous studies and suggest the potential efficacy of lenalidomide in treating patients with MDS/MPN characterized by del 5q, especially when no additional genetic abnormalities are present.

Experience with HCV Detection and Molecular Genetic Characterization among Otherwise Healthy Pregnant Women and Their Partners in the Republic of Guinea.

According to recent data, there are currently 170 to 200 million people infected with HCV worldwide, and the number of new cases annually is approximately 40,000. Thus, the overall prevalence of the pathogen in the world is about 1.8-3%. The dynamic monitoring of circulating viral variants in specific groups that reflect the situation in the wider population, including potential pathogen spread, is of high importance for predicting the epidemiologic situation. Pregnant women are such a group. The Republic of Guinea is one of the poorest countries in the world, in which medicine receives little finance from the state. Among other conditions, HCV infection is not monitored in the country. This work used blood plasma from pregnant women living in the Republic of Guinea and their partners (1810 and 481). ELISA diagnostic kits were used to detect serologic markers, and PCR diagnostic kits were used to detect molecular biologic markers. Sanger sequencing, followed by phylogenetic analysis, was used for genotyping. The present study shows that HCV antibodies were detected in 3.2% of the pregnant women examined and in 3.33% of their male partners. HCV RNA was detected in 0.5% of cases in women and in all anti-HCV-positive male partners (3.33%). HCV RNA was more common in the men than in the pregnant women (χ2 = 25.6, df 1, p < 0.0001, RR = 6.69 with 95% CI: 2.97-15.04). The HCV viral load was determined for all the RNA-HCV-positive samples. The HCV viral load exceeded 1000 IU/mL in all nine women and only in two cases in men. The HCV genes NS5A and NS5B and the NS3 gene fragment were sequenced for 11 samples. Subtype 2q was determined for three isolates and 2j for another three isolates. Another five isolates could not be confidently assigned a subtype because different results were obtained with different methods of analyzing the three viral regions. It can be assumed that these isolates belong to new viral subtypes or to recombinant forms between genotype 2 subtypes. No drug resistance mutations were identified, but a large number of natural polymorphisms in the analyzed genomic regions of the HCV isolates were shown. These results may serve as baseline data for the future planning of a nationwide estimate of the prevalence of bloodborne infections among pregnant women.

Unusual BA222-like strains of Rotavirus A (Sedoreoviridae: Rotavirus: Rotavirus A): molecular and genetic analysis based on all genome segments.

Rotavirus infection is the major cause of severe dehydrating diarrhea requiring hospitalization in young children worldwide. Due to their segmented genome, rotaviruses are capable of gene reassortment, which makes the emergence and spread of genetically novel strains possible. The purpose of this study was to search for unusual rotaviruses circulating in Nizhny Novgorod in 2021‒2023 and their molecular genetic characterization based on all genome segments. Rotavirus-positive stool samples of children were examined by PCR genotyping and electrophoresis in PAAG. cDNA fragments of each of the 11 genes (VP1‒VP4, VP6, VP7, NSP1‒NSP5), 570 to 850 nucleotide pairs in length were sequenced for the selected strains. The phylogenetic analysis was performed in the MEGA X program. In the study period 2021‒2023, 11 G[P] combinations with a predominance of G3P[8] (59.5%) were identified. Six atypical Rotavirus А (RVA) strains were identified: 2 strains of the G2P[4] genotype (G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E2-H3, G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E3-H2) and 4 G3P[9] strains (all strains had the genotype G3-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3). Phylogenetic analysis based on all genes showed an evolutionary relationship between rotaviruses similar to rotaviruses of cats and dogs (BA222-like) and unusual strains of the G2P[4] genotype, for which a mixed combination of genotypes was identified and characterized for the first time. The results obtained expand the understanding of the diversity of reassortant RVAs, as well as complement the data on the genotypic structure of the rotavirus population in Nizhny Novgorod. The wide genetic diversity of reassortant RVA can help rotaviruses overcome the immunological pressure provided by natural and vaccine-induced immunity. In this regard, to control the emergence of new variants and assess changes in the virulence of rotaviruses after reassortment processes, continuous molecular monitoring for circulating RVA is necessary.

First Molecular Detection and Genetic Characterization of Tetratrichomonas buttreyi and Pentatrichomonas hominis in Donkeys in Shanxi Province, China.

Two species of trichomonads, Tetratrichomonas buttreyi and Pentatrichomonas hominis, are common intestinal parasites that can impact animal health and productivity. Severe infection by these parasites can lead to diarrhea and wasting in affected animals. Notably, P. hominis is known to cause diarrhea and has the potential to be transmitted between animals and humans. Donkeys hold significant economic importance in China's agricultural sector. However, whether donkeys are infected with T. buttreyi and P. hominis remains unknown globally. To address this gap in knowledge, 815 fecal samples were collected from donkeys in three representative regions in Shanxi Province, North China. Then, the presence and genetic characteristics of T. buttreyi and P. hominis were examined using species-specific PCR primers amplifying the small subunit ribosomal RNA genes. The overall prevalence was detected to be 25.4% (207/815) for T. buttreyi and 0.7% (6/815) for P. hominis in donkeys in Shanxi Province. All obtained P. hominis sequences were identified as genotype CC1. Genetic analysis revealed that all P. hominis isolates from donkeys were clustered into the same branch with isolates detected in humans, suggesting possible zoonotic transmission. This study is the first to report the occurrence and prevalence of T. buttreyi and P. hominis in donkeys globally. These findings expand the host range of trichomonads and improve our understanding of their genetic diversity and zoonotic potential, providing essential baseline data for the prevention and control of these parasites in donkeys in the region.

Clinical characteristics and molecular genetic analysis of ten cases of ornithine carbamoyltransferase deficiency in southeastern China

BackgroundThis study aimed to investigate the clinical and molecular genetic characteristics of ten children with ornithine carbamoyltransferase deficiency (OTCD) in southeastern China, as well as the correlation between the genotype and phenotype of OTCD.MethodsA retrospective analysis was performed on the clinical manifestations, laboratory testing, and genetic test findings of ten children with OTCD admitted between August 2015 and October 2021 at Quanzhou Maternity and Children’s Hospital of Fujian Province in China.ResultsFive boys presented with early-onset symptoms, including poor appetite, drowsiness, groaning, seizures, and liver failure. In contrast, five patients (one boy and four girls) had late-onset gastrointestinal symptoms as the primary clinical manifestation, all presenting with hepatic impairment, and four with hepatic failure.Nine distinct variants of the OTC gene were identified, including two novel mutations: c.1033del(p.Y345Tfs*50) and c.167T > A(p.M56K). Of seven patients who died, five had early-onset disease despite active treatment. Three patients survived, and two of them underwent liver transplantation.ConclusionsThe clinical manifestations of OTCD lack specificity. However, elevated blood ammonia levels serve as a crucial diagnostic clue for OTCD. Genetic testing aids in more accurate diagnosis and prognosis assessment by clinicians. In addition, we identified two novel pathogenic variants and expand the mutational spectrum of the gene OTC, which may contribute to a better understanding of the clinical and genetic characteristics of OTCD patients.