Germline Gene Research Articles

The molecular basis of the neutralization breadth of the RBD-specific antibody CoV11.

SARS-CoV-2, the virus behind the COVID-19 pandemic, has changed over time to the extent that the current virus is substantially different from what originally led to the pandemic in 2019-2020. Viral variants have modified the severity and transmissibility of the disease and continue do so. How much of this change is due to viral fitness versus a response to immune pressure is hard to define. One class of antibodies that continues to afford some level of protection from emerging variants are those that closely overlap the binding site for angiotensin-converting enzyme 2 (ACE2) on the receptor binding domain (RBD). Some members of this class that were identified early in the course of the pandemic arose from the VH 3-53 germline gene (IGHV3-53*01) and had short heavy chain complementarity-determining region 3s (CDR H3s). Here, we describe the molecular basis of the SARS-CoV-2 RBD recognition by the anti-RBD monoclonal antibody CoV11 isolated early in the COVID-19 pandemic and show how its unique mode of binding the RBD determines its neutralization breadth. CoV11 utilizes a heavy chain VH 3-53 and a light chain VK 3-20 germline sequence to bind to the RBD. Two of CoV11's four heavy chain changes from the VH 3-53 germline sequence, to Ile and to Arg, and some unique features in its CDR H3 increase its affinity to the RBD, while the four light chain changes from the VK 3-20 germline sequence sit outside of the RBD binding site. Antibodies of this type can retain significant affinity and neutralization potency against variants of concern (VOCs) that have diverged significantly from original virus lineage such as the prevalent omicron variant. We also discuss the mechanism by which VH 3-53 encoded antibodies recognize spike antigen and show how minimal changes to their sequence, their choice of light chain, and their mode of binding influence their affinity and impact their neutralization breadth.

Homologous recombination-related (HRR) gene mutation profiling and the association with TMB in Chinese patients with urological cancer.

e16561 Background: Homologous recombination deficiency (HRD) is associated with tumorigenesis and could predict the response of PARP inhibitor (PARPi) therapy and immunotherapy. Loss of function or deleterious mutations in homologous recombination-related (HRR) genes contribute to HRD phenotype. Methods: Tumor tissue samples from 484 Chinese patients with urological cancer were sequenced with 551 cancer-related genes. 957 patients with WES data from the TCGA datasets were included for analysis. Results: In the Chinese cohort, 35.88% (47/131) bladder cancer (BCa) patients, 15.47% (28/181) renal cell carcinoma (RCC) and 37.21% (64/172) prostate cancer (PCa) patients exhibited somatic HRR (sHRR) gene mutations. The most frequently mutated genes were BRCA2 (12% in BCa, 5% in RCC) and CDK12 (17% in PCa), respectively. The germline HRR (gHRR) gene mutations were identified in 62.6% (82/131) BCa, 55.33% (96/180) RCC and 60.62% (97/160) PCa patients. The most frequently mutated gene was BRCA2 (24% in BC, 18% in RCC, 26% in PCa). 7.6% (10/131) BCa patients, 1.7% (3/181) RCC patients and 2.9% (5/173) Pca patients carried both germline and somatic HRR gene mutations. In the TCGA cohort, 38.69% (159/411) BCa patients, 11.62% (43/370) RCC and 6.25% (11/176) PCa patients exhibited somatic HRR (sHRR) gene mutations. The most frequently mutated gene was ATM (14% in BCa, 4% in RCC, 5% in PCa). Interestingly, for the patients with PCa, the somatic mutant frequency of HRR genes in Chinese cohort was higher than that in TCGA cohort (37.21% vs 6.25%, p < 0.001). The sHRR-Mut patients had a higher median TMB compared to the sHRR-WT patients (Chinese cohort: BCa 13.97 vs 4.96, p < 0.001; RCC, 4.96 vs 2.84, p < 0.001; PCa, 5.64 vs 2.84, p < 0.001, TCGA cohort: BCa, 7.21 vs 3.63, p < 0.001; RCC, 1.68 vs 1.42, p = 0.003; PCa, 1.03 vs 0.71, p < 0.001). However, the median TMB was similar between the gHRR-Mut and the gHRR-WT patients (Chinese cohort, BCa 6.38 vs 7.09 p = 0.646; RCC, 3.55 vs 2.84, p = 0.229; PCa, 3.55 vs 2.84, p = 0.111). Conclusions: Our data reported the genetic landscape of HRR gene in Chinese urological cancer patients and suggested that patients with altered HRR genes may be rational candidates for precision oncology treatment and provide new opportunities to predict the tumor response to multiple treatments.

Homologous recombination-related (HRR) gene mutation profiling and the association with TMB in Chinese patients with pancreatic cancer.

e16252 Background: Homologous recombination deficiency (HRD) is associated with tumorigenesis and could predict the response of PARP inhibitor (PARPi) therapy and immunotherapy. Loss of function or deleterious mutations in homologous recombination-related (HRR) genes contribute to HRD phenotype. Methods: Tumor tissue samples from 669 Chinese patients with pancreatic cancer were sequenced with 551 cancer-related genes. Based on the clinical evidence, 15 HRR genes ( ATM, BRCA1, BRCA2, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D, RAD54L, PPP2R2A) were selected. 495 patients with WES data from the TCGA datasets were included for analysis. Results: In the Chinese cohort, 10.46% (70/669) patients exhibited somatic HRR (sHRR) gene mutations. ATM (4%) was the most common mutant gene, followed by BRCA2 (3%), BARD1 (1%), BRCA1 (1%), BRIP1 (1%), RAD51D (1%), CHEK2(1%). The germline HRR (gHRR) gene mutations were identified in 55.67% (118/245) patients. BRCA2 (23%) was the most common mutant gene, followed by ATM (10%), BRCA1 (9%), BRIP1 (9%), PALB2 (8%), BARD1 (7%), FANCL (3%). 1.49% (10/669) patients carried both germline and somatic HRR gene mutations. The sHRR-Mut patients had a higher median TMB compared to the sHRR-WT patients (3.97 vs 2.13, p<0.001). However, the median TMB was similar between the gHRR-Mut and the gHRR-WT patients (2.13 vs 2.13, p=0.49). In the TCGA cohort, 9.09% (45/495) patients exhibited sHRR gene mutations. The most common mutant gene was ATM (4%), followed by CDK12 (2%) BRCA2 (2%), BARD1 (1%). The sHRR-Mut patients had a higher median TMB compared to the sHRR-WT patients (1.03 vs 0.71, p<0.001). Totally, the somatic mutant frequency of HRR genes was similar between Chinese cohort and TCGA cohort (10.46% vs 9.09%, p = 0.113). For the TCGA cohort, the patients with sHRR-Mut had a similar median progression free survival compared to the ones with sHRR-WT (74.4 months vs not reached, p = 0.299). Conclusions: Our data reported the genetic landscape of HRR gene in Chinese pancreatic cancer patients. Patients with somatic HRR gene mutations had a significantly elevated TMB level. Our data suggest that patients with altered HRR genes may be rational candidates for precision oncology treatment and provide new opportunities to predict the tumor response to multiple treatments.

Homologous recombination-related (HRR) gene mutation profiling and the association with TMB in Chinese patients with esophageal and gastric cancer.

e16000 Background: Homologous recombination deficiency (HRD) is associated with tumorigenesis and could predict the response of PARP inhibitor (PARPi) therapy and immunotherapy. Loss of function or deleterious mutations in homologous recombination-related (HRR) genes contribute to HRD phenotype. Methods: Tumor tissue samples from 1237 Chinese patients with esophageal and gastric cancer were sequenced with 551 cancer-related genes. Based on the clinical evidence, 15 HRR genes ( ATM, BRCA1, BRCA2, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D, RAD54L, PPP2R2A) were selected. 623 patients with WES data from the TCGA datasets were included for analysis. Results: In the Chinese cohort, 25.1% (62/247) esophageal cancer (EC) patients and 20.71% (205/990) gastric cancer (GC) patients exhibited somatic HRR (sHRR) gene mutations. The most frequently mutated genes were CHEK2 (7%) in EC and ATM (8%) in GC. The germline HRR (gHRR) gene mutations were identified in 48.16% (118/245) EC patients and 50.66% (498/983) GC patients. BRCA2 was the most common mutant gene (22% in EC and 9% in GC). 4.84% EC patients and 4.14% GC patients carried both germline and somatic HRR gene mutations. The sHRR-Mut patients had a higher median TMB compared to the sHRR-WT patients (EC, 8.09 vs 4.41, p < 0.001; GC, 8.09 vs 4.26, p < 0.001). However, the median TMB was similar between the gHRR-Mut and the gHRR-WT patients (EC, 5.67 vs 5.67, p = 0.903; GC, 4.96 vs 4.41, p = 0.356). In the TCGA cohort, 15.68% (29/185) EC patients and 23.97% (105/438) GC patients exhibited sHRR gene mutations. The most common mutant gene was ATM (5% in EC and 10% in GC). The sHRR-Mut patients had a higher median TMB compared to the sHRR-WT patients (EC, 4.78 vs 2.75, p < 0.001; GC, 21.23 vs 2.65, p < 0.001). For the TCGA gastric cancer cohort, the patients with sHRR-Mut had a significantly better median overall survival compared to the ones with sHRR-WT (46.9 months vs 26.5 months, p = 0.043). Conclusions: Our data reported the genetic landscape of HRR genes in Chinese esophageal and gastric cancer patients. Patients with somatic HRR gene mutations had a significantly elevated TMB level. In gastric cancer, patients carried somatic HRR gene mutations had a significantly prolonged OS.

Genomic landscapes of early-onset versus average-onset colorectal cancer populations.

3536 Background: Early-onset colorectal cancer (eoCRC, initial CRC diagnosis at age < 50 years) has been increasing in the past two decades especially in Western countries. This study evaluates somatic and germline profiles in eoCRC compared to average-onset CRC (aoCRC, initial CRC diagnosis at age ≥ 50 years). Methods: This is a retrospective, cross-sectional study utilizing data from de-identified records of colorectal cancer patients tested with the Tempus xT assay from 2017 to 2022. Briefly, the assay is a targeted panel that detects single nucleotide variants, insertions and/or deletions, and copy number variants in 598-648 genes, as well as chromosomal rearrangements in 22 genes with high sensitivity and specificity. Baseline characteristics and immunologic markers were compared between eoCRC and aoCRC by Wilcoxon Rank Sum or Chi-squared test (reporting p-values). Somatic and germline mutations were compared between two age groups with false discover rate adjustments (reporting q-values). Results: In this study, 2,379 eoCRC and 8,627 aoCRC patients were included, with the majority diagnosed with stage IV disease. Additionally, germline alterations were assessed on a subset of 6,311 patients with tumor/normal match testing (eoCRC = 1,413 and aoCRC = 4,898). Left-sided primaries were more common in eoCRC (85% left/rectum in eoCRC vs. 75% left/rectum in aoCRC (p < 0.001), and rates of microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) were lower compared to aoCRC (4.2% vs. 6.8%, p < 0.001). eoCRC has a unique somatic mutation profile compared to aoCRC. A higher prevalence of germline mutations was observed in eoCRC overall (6.9% vs. 5%, p = 0.006); however, no statistically significant differences were observed in individual germline genes compared to aoCRC, likely due to relatively small numbers. Conclusions: eoCRC has a unique mutational profile and presence of germline mutations in 6.9% of eoCRC, indicating a potential role for universal germline testing in CRC. [Table: see text]

The peripheral TCR repertoire diversity indexes can be used as an independent indicator for long term survival rate of ovarian cancer patients.

e17558 Background: According to GLOBOCAN 2020 data, ovarian cancer (OC) ranks 19th in incidence and 15th in mortality with a rate of 1.6% and 2.1%, respectively, High-grade serous OC is the most common sub-type of malignant ovarian tumors, remains the leading cause of cancer-related death among all gynecological cancers in the developed parts of the world. In the United States in 2016, 5-year survival rate was only 10-25% in stage III or IV OC patients, and there was considerable variability in survival in an advanced stage. At present, there is no reliable molecular marker to identify patients with better or worse prognosis. As is known to all, the adaptive immune system defends the body against different foreign antigens, using two main types of antigen receptors: T-cell receptors (TCRs) and antibodies. Now we use high-throughput sequencing approach to analyze the expressed TCRβ repertoires in the peripheral blood of OC patients and healthy women donors. Methods: The experimental design and participant recruitment were approved by Medical Ethics Committee of West China Second University Hospital (Ethics Approval for Research: 2022). Total RNA was extracted from PBMC using TRIZOL reagent. High through put sequencing of the TCRβ gene, assignment of the Vβ, Dβ, and Jβ germline gene, and TCR diversity indexes analyses were conducted essentially following our previously published protocols. Statistical analysis and graph drawing were performed using R language (R 4.0.3). Results: Comparison of the TCR repertoires between the 232 OC patients (OC group) and the 250 healthy women donors (HD group) revealed significant differences. For examples, the VJ combinations of the OC group were distinct from those of the HD group. In addition, the TCR repertoire diversity indexes of the OC group were significantly lower than those of the HD group ( p < 0.001), including D50s, Simpson indexes, the number of highly expressed clones (HECs), and the frequencies of the largest TCR clones. As reported before, the TCR repertoire diversity indexes decreased gradually with increasing age in the HD group (all p < 0.001). Moreover, the TCR repertoire diversities in the survival group were significantly higher than those in the death group (D50: p = 0.0342; the number of HECs: p = 0.0414). Using as the cut off value, the OC patients with D50 < 0.032 had significantly higher mortality rates compared to the OC patients with D50 > 0.032 ( p = 0.0019). Similarly, using the numbers of HECs or the frequencies of the largest TCR clones can also distinguish OC patients in long term survival. Conclusions: Analyzing the peripheral TCR repertoires in the OC and HD revealed significant differences, and the peripheral TCR repertoire diversity indexes may be used as a potential predictor for long term survival for ovarian cancer.

A pan-cancer statistical study of microsatellite instability and Lynch syndrome–associated mismatch repair genes germline mutations.

10593 Background: Lynch Syndrome (LS), known as hereditary nonpolyposis colorectal cancer (HNPCC1), is caused by germline mutations in the mismatch repair (MMR) genes ( MLH1, MSH2, PMS2, MSH6), or epigenetic silencing of MSH2 which caused by deletion of 3-prime exons of the EPCAM gene and intergenic regions directly upstream of the MSH2 gene. DNA mismatches commonly occur in regions of repetitive nucleotide sequences called microsatellites, and the status of microsatellite instability (MSI) is the key feature in LS-associated cancers. Although there are sporadic reports of MSI and LS in certain cohorts, the real-world status of MSI in large pan-cancer cohort remains to be analyzed. Methods: We retrospectively reviewed all 18189 solid tumor patients from August 1, 2020 to February 5, 2023 from HaploX Genomic Sequencing Center and analyzed their germline mutations in MMR genes ( MLH1,MSH2,PMS2,MSH6 and EPCAM). MSI status was determined using Sanger sequencing or Next-generation sequencing, with tumor MSI status classified as microsatellite instability-high (MSI-H), or microsatellite-stable (MSS). Results: LS-associated germline mutations were detected in 0.313% (n = 57) of patients, and75.4% (n = 43) of patients were identified as MSI-H, and 24.6% (n = 14) of patients were MSS. The patients were grouped into CRC/EC group (colorectal cancer and endometrial cancer) and non-CRC/EC (lung cancer, central nervous system tumor, gastric cancer, esophageal cancer, hepatological cancer, pancreatic adenocarcinoma, small bowel carcinoma, kidney cancer, etc.). Among MSI-H patients, the CRC/EC group accounted for 90.7% (n = 39) and the non-CRC/EC group accounted for 9.3% (n = 4). In MSS patients, the CRC/EC patients accounted for 35.7% (n = 5), and the non-CRC/EC patients accounted for 60% (n = 9). Among patients with MSI-H, the most frequently mutated gene was MSH6 (n = 9): MSH6 (NM_000179) c.3261dup (p.F1088Lfs*5) mutation was detected in 4 patients, of which 2 patients were paternal and both were diagnosed as colorectal cancer; MSH6 c.718C > T (p.R240*) mutation was detected in 2 patients with available MMR IHC results, and one of them was MSH6 negative in IHC staining. Conclusions: Traditionally, a family history of colorectal cancer or endometrial cancers was the primary clinical feature to diagnose Lynch syndrome. Once it was recognized that Lynch-associated CRCs were microsatellite unstable, tumor testing became an additional tool for identification of Lynch syndrome. Some previous studies also reported Lynch syndrome mutations, primarily MSH6 and PMS2, were present in a few MSS patients. Thus, MSI status or family history as diagnostic factor alone may result in Lynch syndrome under-recognized, and additional NGS test on MMR genes should facilitate more accurate diagnosis.

Clinical synergy of universal paired tumor genomic and germline sequencing in an unselected, pan-cancer cohort of patients: Greater than the sum of the parts.

e22537 Background: Germline and tumor next-generation sequencing (NGS) are complementary tests whose benefit in capturing patients (pts) potentially eligible for precision therapies is maximized when the tests are paired, as qualifying pathogenic variants (PVs) are missed if either test was done in isolation (Lincoln et al. 2020). Germline NGS has the additional benefit of informing prevention through surveillance and cascade testing. We highlight the benefits of a universal approach to concurrent testing in a subset of the previously reported cohort of pan-cancer pts who underwent universal germline NGS (Samadder et al. 2020). Methods: Unselected pts with solid tumors underwent an 80+ gene germline panel and 315+ gene tumor panel. Variants in genes unique to the germline or tumor panels, including microsatellite instability (MSI) and tumor mutation burden (TMB), were also evaluated. Results: 104 pts [81.7% White, non-Hispanic, 71.2% male] with 23 cancer types [28% colorectal, 13% lung, 11% prostate, 49% other] were included. Five (5%) pts had no actionable tumor alterations or germline variants identified (Table). 18 pts (17%) had 19 pathogenic germline variants (PGVs) identified, 11 (58%) of which were detected on tumor NGS (Table). 92 pts had >1 tumor alteration identified, of which 12% were confirmed as PGVs (Table). Notably, tumor NGS revealed 81 pts (78%) pts with biomarkers that would could not have been identified with germline testing alone, such as variants in genes not on germline panel (80) or MSI-high (4), or TMB-high (21) status of the tumor. Conclusions: Germline and tumor NGS are complementary tests that often detect different actionable alterations. There is value in confirming both the presence and absence of somatic variants in the germline in order to make appropriate clinical recommendations for the patient and their family members. [Table: see text]

Genetic and Epigenetic Regulation of Drosophila Oocyte Determination.

Primary oocyte determination occurs in many organisms within a germ line cyst, a multicellular structure composed of interconnected germ cells. However, the structure of the cyst is itself highly diverse, which raises intriguing questions about the benefits of this stereotypical multicellular environment for female gametogenesis. Drosophila melanogaster is a well-studied model for female gametogenesis, and numerous genes and pathways critical for the determination and differentiation of a viable female gamete have been identified. This review provides an up-to-date overview of Drosophila oocyte determination, with a particular emphasis on the mechanisms that regulate germ line gene expression.

Identification and characterization of IgNAR and VNAR repertoire from the ocellate spot skate (Okamejei kenojei)

Elasmobranchs are crucial for comparative studies of evolution, as they belong to the most ancient vertebrate lineages that survived numerous extinction events and persist until today. The immunoglobulin new antigen receptor (IgNAR) found in sharks and heavy-chain-only antibody (HCAb) found in camelidae are products of convergent evolution. Although it was previously believed that IgNAR emerged 220 million years ago, before the divergence of sharks and skates, there is limited evidence to support this. In this study, we provide data supporting the existence of IgNAR in the ocellate spot skate (Okamejei kenojei) mononuclear cell transcriptome and peripheral blood serum. Additionally, we characterize the germline gene configuration of the ocellate spot skate IgNAR V domain. The ocellate spot skate IgNAR structure prediction and VNAR crystal structure exhibit high similarity to their shark counterparts. These data strongly suggest that IgNAR in both sharks and skates share a common ancestor. Sequencing of the ocellate spot skate VNAR repertoire provided crucial data for further understanding of the IgNAR generation. Notably, we discovered that approximately 99% of the ocellate spot skate VNARs belonged to type IV. This represents an exceptionally high proportion of type IV within the VNAR repertoire, which has not been documented in previously studied elasmobranchs. This unique characteristic of the ocellate spot skate VNAR adds essential structural diversity to the naïve VNAR library from elasmobranchs and could potentially benefit the development of pharmaceutical drugs.

Role of complementarity-determining regions 1 and 3 in pathologic amyloid formation by human immunoglobulin κ1 light chains

Background Immunoglobulin light chain (LC) amyloidosis is a life-threatening disease complicated by vast numbers of patient-specific mutations. We explored 14 patient-derived and engineered proteins related to κ1-family germline genes IGKVLD-33*01 and IGKVLD-39*01. Methods Hydrogen-deuterium exchange mass spectrometry analysis of conformational dynamics in recombinant LCs and their fragments was integrated with studies of thermal stability, proteolytic susceptibility, amyloid formation and amyloidogenic sequence propensity. The results were mapped on the structures of native and fibrillary proteins. Results Proteins from two κ1 subfamilies showed unexpected differences. Compared to their germline counterparts, amyloid LC related to IGKVLD-33*01 was less stable and formed amyloid faster, whereas amyloid LC related to IGKVLD-39*01 had similar stability and formed amyloid slower, suggesting different major factors influencing amyloidogenesis. In 33*01-related amyloid LC, these factors involved destabilization of the native structure and probable stabilization of amyloid. The atypical behavior of 39*01-related amyloid LC stemmed from increased dynamics/exposure of amyloidogenic segments in βC′V and βEV that could initiate aggregation and decreased dynamics/exposure near the Cys23–Cys88 disulfide. Conclusions The results suggest distinct amyloidogenic pathways for closely related LCs and point to the complementarity-defining regions CDR1 and CDR3, linked via the conserved internal disulfide, as key factors in amyloid formation.

A Caenorhabditis elegans Male Pheromone Feminizes Germline Gene Expression in Hermaphrodites and Imposes Life-History Costs.

Sex pheromones not only improve the reproductive success of the recipients, but also impose costs, such as a reduced life span. The underlying mechanisms largely remain to be elucidated. Here, we show that even a brief exposure to physiological amounts of the dominant Caenorhabditis elegans male pheromone, ascr#10, alters the expression of thousands of genes in hermaphrodites. The most dramatic effect on the transcriptome is the upregulation of genes expressed during oogenesis and the downregulation of genes associated with male gametogenesis. This result reveals a way in which social signals help to resolve the inherent conflict between spermatogenesis and oogenesis in a simultaneous hermaphrodite, presumably to optimally align reproductive function with the presence of potential mating partners. We also found that exposure to ascr#10 increased the risk of persistent intestinal infections in hermaphrodites due to pathological pharyngeal hypertrophy. Thus, our study reveals ways in which the male pheromone can not only have beneficial effects on the recipients' reproduction, but also cause harmful consequences that reduce life span.

Untangling associations between immunoglobulin genotypes, repertoires and function

Immunoglobulin (IG) genes, encoding B cell receptors (BCRs), are fundamental components of the mammalian immune system, which evolved to recognize the diverse antigenic universe present in nature. To handle these myriad inputs, BCRs are generated through combinatorial recombination of a set of highly polymorphic germline genes, resulting in a vast repertoire of antigen receptors that initiate responses to pathogens and regulate commensals. Following antigen recognition and B cell activation, memory B cells and plasma cells form, allowing for the development of anamnestic antibody (Ab) responses. How inherited variation in IG genes impacts host traits, disease susceptibility, and Ab recall responses is a topic of great interest. Here, we consider approaches to translate emerging knowledge about IG genetic diversity and expressed repertoires to inform our understanding of Ab function in health and disease etiology. As our understanding of IG genetics grows, so will our need for tools to decipher preferences for IG gene or allele usage in different contexts, to better understand antibody responses at the population level.

De novo mutation of NAXE (APOAIBP)-related early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1: A case report

Early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1 (PEBEL1) is a rare autosomal recessive severe neurometabolic disease. The aim of this study was to investigate the clinical characteristics and genetic pathogenicity of PEBEL1 caused by rare NAXE (or APOA1BP)-related defects. The patient was a girl aged 2 years and 10 mo. She was hospitalized due to walking disorder for > 40 d. The clinical manifestations were ataxia, motor function regression, hypotonia, and eyelid ptosis. Within 1 mo of hospitalization, she developed sigh breathing, respiratory failure, cerebellar edema and brain hernia, and finally she died. Changes were found in cranial imaging, including cerebellar edema accompanied by symmetrical myelopathy. Through whole exome sequencing, we detected NAXE compound heterozygous variation (NM 144772.3) c.733A>C (p. Lys245Gln, dbSNP: rs770023429) and novel variation c.370G>T (p.Gly124Cys) in the germline gene. The clinical features and core phenotypes of this case were consistent with 18 previously reported cases of PEBEL1. This is the first case of NAXE-related PEBEL1 with severe clinical phenotype in Mainland China. The p.Gly124Cys mutation discovered in this case has enriched the pathogenic variation spectrum of NAXE.

Towards an appropriate African framework for public engagement with human genome editing: a call to synergistic action.

The CRISPR-Cas9 system has revolutionised the biotechnology of human genome editing. Human germline gene editing promises exponential benefits to many in Africa and elsewhere, especially those affected by the highly prevalent monogenic disorders - for which, thanks to CRISPR, a relatively safe heritable radical therapy is a real possibility. Africa evidently presents a unique opportunity for empirical research in human germline gene editing because of its high prevalence of monogenic disorders. Critically, however, germline gene editing has raised serious ethical concerns especially because of the significant risks of inadvertent and intentional misuse of its transgenerational heritability. Calls for due prudence have become even more pronounced in the wake of the 2018 case of He Jiankui's 'CRISPR'd babies'. Meanwhile, Africa is seriously lagging in articulating its position on human genome editing. Conspicuously, there has been little to no attempt at comprehensively engaging the African public in discussions on the promises and concerns about human genome editing. Thus, the echoing key question remains as to how Africa should prudently embrace and govern this revolutionary biotechnology. In this article, therefore, I lay the groundwork for the possible development of an appropriate African framework for public engagement with human genome editing and call upon all stakeholders to urgent synergistic action. I particularly highlight the World Health Organisation's possible leadership role in promptly establishing the requisite expert working group for this urgent need.

Adjuvant and neoadjuvant approaches in pancreatic cancer.

Pancreatic cancer treatment remains a challenging problem for surgeons and oncologists. This review aims to summarize the current advances on adjuvant and neoadjuvant treatment approaches for resectable pancreatic cancer. Recent phase III randomized trials of adjuvant therapy showed improvement of overall survival in both experimental and control groups. Effectiveness of adjuvant therapy in specific subgroups as elderly patients, intraductal papillary mucinous neoplasms, stage I, and DNA damage repair gene germline variants has been reported. Completion of all cycles of planned adjuvant chemotherapy is confirmed as an independent prognostic factor. Adjuvant chemotherapy remains underutilized, mainly because of early recurrence, prolonged recovery, or older age older than 75 years. So, neoadjuvant treatment is a logical approach to administer systemic treatment to more patients. Meta-analysis did not demonstrate an overall survival benefit of neoadjuvant treatments in resectable pancreatic cancer, and definitive conclusions cannot be drawn from available randomized controlled trials. Upfront surgery and adjuvant chemotherapy should still be considered a standard approach in resectable pancreatic cancer. Adjuvant chemotherapy with mFOLFIRINOX remains the standard of care in fit patients with resected pancreatic cancer, and limited high-level evidence support the use of neoadjuvant therapy in upfront resectable pancreatic cancer.

Molecular basis of SARS-CoV-2 Omicron variant evasion from shared neutralizing antibody response

Understanding the molecular features of neutralizing epitopes is important for developing vaccines/therapeutics against emerging SARS-CoV-2 variants. We describe three monoclonal antibodies (mAbs) generated from COVID-19 recovered individuals during the first wave of the pandemic in India. These mAbs had publicly shared near germline gene usage and potently neutralized Alpha and Delta, poorly neutralized Beta, and failed to neutralize Omicron BA.1 SARS-CoV-2 variants. Structural analysis of these mAbs in complex with trimeric spike protein showed that all three mAbs bivalently bind spike with two mAbs targeting class 1 and one targeting a class 4 receptor binding domain epitope. The immunogenetic makeup, structure, and function of these mAbs revealed specific molecular interactions associated with the potent multi-variant binding/neutralization efficacy. This knowledge shows how mutational combinations can affect the binding or neutralization of an antibody, which in turn relates to the efficacy of immune responses to emerging SARS-CoV-2 escape variants.

Enhanced Mott cell formation linked with IgM Fc receptor (FcμR) deficiency.

In previous studies, Mott cells, an unusual form of plasma cells containing Ig-inclusion bodies, were frequently observed in peripheral lymphoid tissues in our IgM Fc receptor (FcμR)-deficient (KO) mouse strain. Because of discrepancies in the reported phenotypes of different Fcmr KO mouse strains, we here examined two additional available mutant strains and confirmed that such enhanced Mott-cell formation was a general phenomenon associated with FcμR deficiency. Splenic B cells from Fcmr KO mice clearly generated more Mott cells than those from WT mice when stimulated in vitro with LPS alone or a B-1, but not B-2, activation cocktail. Nucleotide sequence analysis of the Ig variable regions of a single IgMλ+ Mott-hybridoma clone developed from splenic B-1 B cells of Fcmr KO mice revealed the near (VH) or complete (Vλ) identity with the corresponding germline gene segments and the addition of six or five nucleotides at the VH/DH and DH/JH junctions, respectively. Transduction of an FcμR cDNA into the Mott hybridoma significantly reduced cells containing IgM-inclusion bodies with a concomitant increase in IgM secretion, leading to secreted IgM binding to FcμR expressed on Mott transductants. These findings suggest a regulatory role of FcμR in the formation of Mott cells and IgM-inclusion bodies.

Germline genetic variants in pheochromocytoma/paraganglioma: single-center experience.

Pheochromocytoma and paragangliomas (PPGLs) are rare neuroendocrine tumors carrying 25-40% pathogenic germline gene variants (PGVs). We evaluated clinical, laboratory, and germline molecular profile of 115 patients with pathologic (14 patients were relatives from 8 different families recruited for genetic survey) confirmed PPGL followed in our institution. Patients with classic MEN2A/MEN2B phenotypes and at-risk relatives underwent direct analysis of RET proto-oncogene, and the remaining had samples submitted to complete next-generation sequencing aiming 23 PPGL-related genes: ATM, ATR, CDKN2A, EGLN1, FH, HRAS, KIF1B, KMT2D, MAX, MDH2, MERTK, MET, NF1, PIK3CA, RET, SDHA, SDHAF2, SDHB, SDHC, SDHD, TMEM127, TP53, and VHL. We also developed a clinical judgment score (CJS) to determine the probability of patients having a potentially hereditary disease. The resulting genetic landscape showed that 67 patients (58.3%) had variants in at least one gene: 34 (50.7%) had exclusively pathogenic or likely pathogenic variants, 13 (19.4%) had pathogenic or likely pathogenic variants and variant of undetermined significance (VUS), and 20 (29.8%) carried only VUS. PGVs were found in RET (n = 18; 38.3%), VHL (n = 10; 21.3%), SDHB and NF1 (n = 8; 17% each), and MAX, SDHD, TMEM127, and TP53 (n = 1; 2.1% each). Direct genetic testing disclosed 91.3% sensitivity, 81.2% specificity, and 76.4% and 93.3% positive predictive value (PPV) and negative predictive values (NPV), respectively. The CJS to identify patients who would not benefit from genetic testing had 75% sensitivity, 96.4% specificity, and 60% and 98.2% PPV and NPV, respectively. In summary, the landscape of PPGL germline gene variants from 115 Brazilian patients resulted in slightly higher prevalent pathogenic and likely pathogenic variants, especially in the RET gene. We suggest a CJS to identify PPGL patients who would not require initial genetic evaluation, improving test specificity and reducing costs.

Cytochrome P450 Oxidoreductase (POR) Associated with Severe Paclitaxel-Induced Peripheral Neuropathy in Patients of European Ancestry from ECOG-ACRIN E5103.

Paclitaxel is a widely used anticancer therapeutic. Peripheral neuropathy is the dose-limiting toxicity and negatively impacts quality of life. Rare germline gene markers were evaluated for predicting severe taxane-induced peripheral neuropathy (TIPN) in the patients of European ancestry. In addition, the impact of Cytochrome P450 (CYP) 2C8, CYP3A4, and CYP3A5 metabolizer status on likelihood of severe TIPN was also assessed. Whole-exome sequencing analyses were performed in 340 patients of European ancestry who received a standard dose and schedule of paclitaxel in the adjuvant, randomized phase III breast cancer trial, E5103. Patients who experienced grade 3-4 (n = 168) TIPN were compared to controls (n = 172) who did not experience TIPN. For the analyses, rare variants with a minor allele frequency ≤ 3% and predicted to be deleterious by protein prediction programs were retained. A gene-based, case-control analysis using SKAT was performed to identify genes that harbored an imbalance of deleterious variants associated with increased risk of severe TIPN. CYP star alleles for CYP2C8, CYP3A4, and CYP3A5 were called. An additive logistic regression model was performed to test the association of CYP2C8, CYP3A4, and CYP3A5 metabolizer status with severe TIPN. Cytochrome P450 oxidoreductase (POR) was significantly associated with severe TIPN (P value = 1.8 ×10-6). Six variants were predicted to be deleterious in POR. There were no associations between CYP2C8, CYP3A4, or CYP3A5 metabolizer status with severe TIPN. Rare variants in POR predict an increased risk of severe TIPN in patients of European ancestry who receive paclitaxel.