Alteration of Cadherin 3 Expression and DNA Methylation in Association with Aggressive Renal Cell Carcinoma.

Cadherins (calcium-dependent adhesion proteins) are important in cellular adhesion and may play a role in the development and progression of renal cell carcinoma (RCC). This study investigated changes in cadherin 3 (CDH3; P-cadherin) mRNA expression, DNA methylation, and protein expression in RCC and compared the results with the histopathological and clinical characteristics of patients. The possible contribution of CDH3 to tumor cell invasiveness was tested in a functional assay using siRNA-based suppression of CDH3 expression and subsequent real-time impedance analysis using a Matrigel invasion model. Our analyses revealed a tumor-specific loss of CDH3 mRNA expression, CDH3 DNA hypermethylation, and loss of distal tubular and collecting duct CDH3 protein expression in RCC. A relatively higher methylation level in tumors was associated with a loss of cell differentiation and higher clinical stage. siRNA-induced suppression of CDH3 expression modulated the invasion characteristics of tumor cells in the impedance-based real-time cellular analysis. Our results indicate that loss of CDH3 expression is common in RCC and may contribute to the pathogenesis of a subset of RCC. Further studies to reveal the mechanisms of loss of expression and its effects on the invasive behavior of renal tumor cells are required.

Diagnostic Yield and Therapeutic Consequences of Targeted Next-Generation Sequencing in Sporadic Primary Immunodeficiency.

INTRODUCTION: Primary immunodeficiencies (PIDs) are a heterogeneous group of disorders characterized by increased susceptibility to infections, immune dysregulation, and/or malignancy. Genetic studies, especially during the last decade, led to a better understanding of the pathogenesis of primary immunodeficiencies and contributed to their classification into distinct monogenic disorders falling under one of the >430 currently known inborn errors of immunity (IEI). The growing availability of molecular genetic testing resulted in the increasing identification of patients with IEI. Here, we evaluated the diagnostic yield and the clinical consequences of targeted next-generation sequencing (tNGS) in a cohort of 294 primary immunodeficiency patients, primarily consisting of cases with sporadic primary antibody deficiency. METHOD: We have custom designed a tNGS panel to sequence a cohort of PID patients. Agilent's HaloPlex Target Enrichment System for Illumina was used for DNA target enrichment. RESULTS: tNGS identified a definite or predicted pathogenic variant in 15.3% of patients. The highest diagnostic rate was observed among patients with combined immunodeficiency or immune dysregulation, for whom genetic diagnosis may affect therapeutic decision-making. CONCLUSION: Next-generation sequencing has changed diagnostic assignment and paved the way for targeted therapeutic intervention with agents directed at reverting the disease-causing molecular abnormality or its pathophysiological consequences. Therefore, such targeted therapies and identifying the genetic basis of PID can be essential for patients with manifested immune dysregulation as conventional immunomodulatory regimens may exert an immunosuppressive effect, aggravating their immunodeficiency or may only inadequately control autoimmune or lymphoproliferative manifestations.

High frequency of variants in genes associated with primary immunodeficiencies in patients with rheumatic diseases with secondary hypogammaglobulinaemia.

OBJECTIVES: Treatment of rheumatic diseases requires immunomodulatory agents which can compromise antibody production. However, even in case of agents directly targeting B cells, a minority of patients develop hypogammaglobulinaemia, suggesting a genetic predisposition, which has not been investigated so far. The phenotypic overlap between primary immunodeficiency disorders (PIDs) and rheumatic diseases suggests a shared genetic basis, especially in case of patients with rheumatic diseases with hypogammaglobulinaemia. METHODS: 1008 patients with rheumatic diseases visiting the outpatient clinics of the Hannover University Hospital were screened for hypogammaglobulinaemia. Those with persistent hypogammaglobulinaemia and an equal number of patients without it underwent targeted next-generation sequencing, searching for variations in genes linked with hypogammaglobulinaemia in the context of PIDs. RESULTS: We identified 33 predicted pathogenic variants in 30/64 (46.9%) patients with persistent secondary hypogammaglobulinaemia. All 33 variants were monoallelic and 10 of them in 10/64 (15.6%) patients were found in genes associated with autosomal dominant PIDs. 2/64 (3.1%) patients harboured variants which were previously reported to cause PIDs. In the group without hypogammaglobulinaemia we identified seven monoallelic variants in 7/64 (10.9%), including a variant in a gene associated with an autosomal dominant PID. CONCLUSIONS: Approximately half of patients with persistent secondary hypogammaglobulinaemia harboured at least a variant in a PID gene. Despite the fact that previous immunomodulatory treatment is an exclusion criterion in the diagnosis of PIDs, we identified genetic variants that can account for PID in patients with clear rheumatic phenotypes who developed hypogammaglobulinaemia after the introduction of immunomodulatory treatment. Our data suggest the common genetic causes of primary and secondary hypogammaglobulinaemia.

DNA methylation of tumor associated calcium signal transducer 2 (TACSTD2) loci shows association with clinically aggressive renal cell cancers.

BACKGROUND: DNA methylation is frequently observed in the development and progression of many human tumors as well as renal cell cancer (RCC). Tumor Associated Calcium Signal Transducer 2 (TACSTD2) participates in cell cycle progression through MAPK signalling pathway activation. Moreover, tumor-specific hypermethylation and association with aggressive cancer characteristics has been found for lung adenocarcinoma, hepatocellular carcinoma and cholangiocarcinoma. Whether TACSTD2 is tumor specifically hypermethylated in RCC or shows association of methylation with adverse clinicopathological parameters and survival of patients has not been investigated at yet. METHODS: Quantitative methylation-specific PCR (qMSP) analysis of a locus in the intron 1 region of TACSTD2 gene was carried out in a cross-sectional study of 127 paired RCC and normal samples. In silico analysis of TACSTD2 methylation in the TCGA Kidney Renal Clear Cell Carcinoma (KIRC) dataset of 280 patients served as validation cohort. Statistical analyses were carried out using the two-sided paired t-test for matched tumor and normal sample comparisons, logistic regression for subgroup comparisons, Cox regression for analysis of recurrence free survival (RFS) and Pearson correlation analysis for correlation of TACSTD2 methylation and TACSTD2 mRNA in KIRC data. RESULTS: Higher methylation levels in RCC were significantly associated with advanced disease (p < 0.001), high tumor stage (p = 0.003), tumor differentiation (p = 0.033) and presence of lymph node (p = 0.021) or distant metastases (p = 0.008). TACSTD2 hypermethylation was associated with a shorter RFS of patients and demonstrate statistical independency from clinical parameters as state of metastasis, tumor stage, grade and state of advanced disease. In silico validation using TCGA KIRC data also demonstrated association of TACSTD2 loci with adverse clinicopathology and shortened RFS of patients. In addition, in silico analyses of TCGA KIRC data showed an inverse correlation between DNA methylation levels of TACSTD2 and mRNA expression. CONCLUSIONS: Our results suggest an association between TACSTD2 methylation and disease progression and clinical course of RCC.

Patient survival and tumor characteristics associated with CHEK2:p.I157T - findings from the Breast Cancer Association Consortium.

BACKGROUND: P.I157T is a CHEK2 missense mutation associated with a modest increase in breast cancer risk. Previously, another CHEK2 mutation, the protein truncating c.1100delC has been associated with poor prognosis of breast cancer patients. Here, we have investigated patient survival and characteristics of breast tumors of germ line p.I157T carriers. METHODS: We included in the analyses 26,801 European female breast cancer patients from 15 studies participating in the Breast Cancer Association Consortium. We analyzed the association between p.I157T and the clinico-pathological breast cancer characteristics by comparing the p.I157T carrier tumors to non-carrier and c.1100delC carrier tumors. Similarly, we investigated the p.I157T associated risk of early death, breast cancer-associated death, distant metastasis, locoregional relapse and second breast cancer using Cox proportional hazards models. Additionally, we explored the p.I157T-associated genomic gene expression profile using data from breast tumors of 183 Finnish female breast cancer patients (ten p.I157T carriers) (GEO: GSE24450). Differential gene expression analysis was performed using a moderated t test. Functional enrichment was investigated using the DAVID functional annotation tool and gene set enrichment analysis (GSEA). The tumors were classified into molecular subtypes according to the St Gallen 2013 criteria and the PAM50 gene expression signature. RESULTS: P.I157T was not associated with increased risk of early death, breast cancer-associated death or distant metastasis relapse, and there was a significant difference in prognosis associated with the two CHEK2 mutations, p.I157T and c.1100delC. Furthermore, p.I157T was associated with lobular histological type and clinico-pathological markers of good prognosis, such as ER and PR expression, low TP53 expression and low grade. Gene expression analysis suggested luminal A to be the most common subtype for p.I157T carriers and CDH1 (cadherin 1) target genes to be significantly enriched among genes, whose expression differed between p.I157T and non-carrier tumors. CONCLUSIONS: Our analyses suggest that there are fundamental differences in breast tumors of CHEK2:p.I157T and c.1100delC carriers. The poor prognosis associated with c.1100delC cannot be generalized to other CHEK2 mutations.

Decreased GATA5 mRNA expression associates with CpG island methylation and shortened recurrence-free survival in clear cell renal cell carcinoma.

BACKGROUND: GATA-5, a zinc-finger transcription factor and member of the GATA family proteins 1-6, is known to be involved in cellular differentiation. We recently found that tumor-specific hypermethylation of the GATA5 CpG island (CGI) occurs in renal cell carcinoma (RCC) and is associated with an adverse clinical outcome. In this study, we investigated whether epigenetic GATA5 alterations may result in changes in GATA5 mRNA expression levels and correlate with the observed prognostic impact of epigenetic changes in GATA5 in RCC. METHODS: Quantitative real-time reverse-transcribed polymerase chain reaction was applied to measure relative GATA5 mRNA expression levels in 135 kidney tissue samples, including 77 clear cell RCC (ccRCC) tissues and 58 paired adjacent normal renal tissue samples. Relative GATA5 expression levels were determined using the ΔΔCt method and detection of three endogenous control genes then compared to previously measured values of relative methylation. RESULTS: The mean relative GATA5 mRNA expression level exhibited an approximately 31-fold reduction in tumor specimens compared with corresponding normal tissues (p < 0.001, paired t-test). Decreased GATA5 mRNA expression was inversely correlated with increased GATA5 CGI methylation (p < 0.001) and was associated with shortened recurrence-free survival in ccRCC patients (p = 0.023, hazard ratio = 0.25). CONCLUSION: GATA5 mRNA expression is decreased in ccRCC, likely due to gene silencing by methylation of the GATA5 CGI. Moreover, reduced GATA5 mRNA levels were associated with a poor clinical outcome, indicating a possible role of GATA5 for the development of aggressive ccRCC phenotypes.

Nonsense mutation p.Q548X in BLM, the gene mutated in Bloom's syndrome, is associated with breast cancer in Slavic populations.

Bloom's syndrome is a rare autosomal recessive chromosomal instability disorder with a high incidence of various types of neoplasia, including breast cancer. Whether monoallelic BLM mutations predispose to breast cancer has been a long-standing question. A nonsense mutation, p.Q548X, has recently been associated with an increased risk for breast cancer in a Russian case-control study. In the present work, we have investigated the prevalence of this Slavic BLM founder mutation in a total of 3,188 breast cancer cases and 2,458 controls from Bashkortostan, Belarus, Ukraine, and Kazakhstan. The p.Q548X allele was most frequent in Russian patients (0.8 %) but was also prevalent in Byelorussian and Ukrainian patients (0.5 and 0.6 %, respectively), whereas it was absent in Altaic or other non-European subpopulations. In a combined analysis of our four case-control series, the p.Q548X mutation was significantly associated with breast cancer (Mantel-Haenszel OR 5.1, 95 % CI 1.2; 21.9, p = 0.03). A meta-analysis with the previous study from the St. Petersburg area corroborates the association (OR 5.7, 95 % CI 2.0; 15.9, p = 3.7 × 10(-4)). A meta-analysis for all published truncating mutations further supports the association of BLM with breast cancer, with an estimated two- to five-fold increase in risk (OR 3.3, 95 %CI 1.9; 5.6, p = 1.9 × 10(-5)). Altogether, these data indicate that BLM is not only a gene for Bloom's syndrome but also might represent a breast cancer susceptibility gene.

Corrigendum: Vulnerability to meningococcal disease in immunodeficiency due to a novel pathogenic missense variant in NFKB1.

[This corrects the article DOI: 10.3389/fimmu.2021.767188.].

Rituximab to treat prolidase deficiency due to a novel pathogenic copy number variation in PEPD.

Prolidase deficiency (PD) is a rare autosomal recessive inborn error of immunity caused by biallelic homozygous or compound heterozygous loss-of-function mutations in PEPD, the gene that encodes prolidase. PD typically manifests with variable dysmorphic features, chronic cutaneous ulcers, recurrent infections and autoimmune features, including systemic lupus erythematosus. So far, there is no consensus regarding treatment of PD and its autoimmune manifestations. Here, we present a 28-year-old female patient with PD due to a novel homozygous intragenic deletion in PEPD, diagnosed at the age of 6 years and 7 months with an undifferentiated connective tissue disease that, apart from its very early onset, would be consistent with the diagnosis of Sjögren's syndrome. Steroids and diverse conventional synthetic disease-modifying antirheumatic drugs failed to control PD-associated vasculitis and mucocutaneous ulcerations and led to infectious complications, including cytomegalovirus colitis. Introduction of rituximab (RTX) treatment in this patient led to sustained recession of mucocutaneous ulceration, enabling tapering of steroids. High interleukin-1ß (IL-1ß) production by this patient's monocytes, together with the detection of both IL-1ß and interleukin-18 (IL-18) in her serum, suggest enhanced inflammasome activation in PD, whereas the therapeutic efficacy of RTX implies a role for CD20 positive B cells in the complex immunopathogenesis of PD.

A role for XRCC2 gene polymorphisms in breast cancer risk and survival.

BACKGROUND: The XRCC2 gene is a key mediator in the homologous recombination repair of DNA double strand breaks. It is hypothesised that inherited variants in the XRCC2 gene might also affect susceptibility to, and survival from, breast cancer. METHODS: The study genotyped 12 XRCC2 tagging single nucleotide polymorphisms (SNPs) in 1131 breast cancer cases and 1148 controls from the Sheffield Breast Cancer Study (SBCS), and examined their associations with breast cancer risk and survival by estimating ORs and HRs, and their corresponding 95% CIs. Positive findings were further investigated in 860 cases and 869 controls from the Utah Breast Cancer Study (UBCS) and jointly analysed together with available published data for breast cancer risk. The survival findings were further confirmed in studies (8074 cases) from the Breast Cancer Association Consortium (BCAC). RESULTS: The most significant association with breast cancer risk in the SBCS dataset was the XRCC2 rs3218408 SNP (recessive model p=2.3×10(-4), minor allele frequency (MAF)=0.23). This SNP yielded an OR(rec) of 1.64 (95% CI 1.25 to 2.16) in a two-site analysis of SBCS and UBCS, and a meta-OR(rec) of 1.33 (95% CI 1.12 to 1.57) when all published data were included. This SNP may mark a rare risk haplotype carried by two in 1000 of the control population. Furthermore, the XRCC2 coding R188H SNP (rs3218536, MAF=0.08) was significantly associated with poor survival, with an increased per-allele HR of 1.58 (95% CI 1.01 to 2.49) in a multivariate analysis. This effect was still evident in a pooled meta-analysis of 8781 breast cancer patients from the BCAC (HR 1.19, 95% CI 1.05 to 1.36; p=0.01). CONCLUSIONS: These findings suggest that XRCC2 SNPs may influence breast cancer risk and survival.

Identification of variants in genes associated with autoinflammatory disorders in a cohort of patients with psoriatic arthritis.

OBJECTIVES: Besides adaptive immunity genes, genetic risk factors for psoriatic arthritis (PsA) include innate immunity loci, which suggests an autoinflammatory disease mechanism, at least in a subset of patients. Here, we aimed at investigating the autoinflammatory genetic background of PsA. METHODS: A total of 120 patients with PsA visiting the outpatient clinics of the Hannover University hospital underwent targeted next-generation sequencing, searching for variations in genes linked with inborn errors of immunity classified as autoinflammatory disorders (AIDs). Deleteriousness of rare variants was evaluated through in silico analysis. RESULTS: We found 45 rare predicted deleterious variants in 37 out of 120 (30.8%) patients with PsA. Relatively common were variants in AP1S3, PLCG2, NOD2 and NLRP12. All 45 variants were monoallelic and 25 of them, identified in 20 out of 120 (16.7%) patients, were localised in genes associated with autosomal dominant (AD) disorders. Detection of those variants is associated with pustular psoriasis or a coexisting inflammatory bowel disease (IBD). CONCLUSIONS: Approximately 30% of patients with PsA harboured at least one variant in a gene associated with an AID, suggesting an autoinflammatory disease mechanism. Detection of variants in genes linked to AD-AIDs may explain extra-articular manifestations of PsA, such as pustular psoriasis and IBD.

Cellular and molecular mechanisms breaking immune tolerance in inborn errors of immunity.

In addition to susceptibility to infections, conventional primary immunodeficiency disorders (PIDs) and inborn errors of immunity (IEI) can cause immune dysregulation, manifesting as lymphoproliferative and/or autoimmune disease. Autoimmunity can be the prominent phenotype of PIDs and commonly includes cytopenias and rheumatological diseases, such as arthritis, systemic lupus erythematosus (SLE), and Sjogren's syndrome (SjS). Recent advances in understanding the genetic basis of systemic autoimmune diseases and PIDs suggest an at least partially shared genetic background and therefore common pathogenic mechanisms. Here, we explore the interconnected pathogenic pathways of autoimmunity and primary immunodeficiency, highlighting the mechanisms breaking the different layers of immune tolerance to self-antigens in selected IEI.

Vulnerability to Meningococcal Disease in Immunodeficiency Due to a Novel Pathogenic Missense Variant in NFKB1.

NF-κB1 deficiency is suggested to be the most common cause of common variable immunodeficiency (CVID). NFKB1 encodes for the p105 precursor protein of NF-κB1, which is converted into the active transcriptional subunit p50 through proteasomal processing of its C-terminal half upon stimulation and is implicated in the canonical NF-kB pathway. Rare monoallelic NFKB1 variants have been shown to cause (haplo) insufficiency. Our report describes a novel NFKB1 missense variant (c.691C>T, p.R230C; allele frequency 0.00004953) in a family vulnerable to meningitis, sepsis, and late-onset hypogammaglobulinemia. We investigated the pathogenic relevance of this variant by lymphocyte stimulation, immunophenotyping, overexpression study and immunoblotting. The ectopic expression of p50 for c.691 C>T restricted transcriptionally active p50 in the cytoplasm, and immunoblotting revealed reduced p105/50 expression. This study shows that the deleterious missense variant in NFKB1 adversely affects the transcriptional and translational activity of NFκB1, impairing its function. Patients immunological parameters show a progressive course of hypogammaglobulinemia, which may partially account for the incomplete disease penetrance and suggest the need for closer immunological monitoring of those mutation carriers.

DNA Methylation in INA, NHLH2, and THBS4 Is Associated with Metastatic Disease in Renal Cell Carcinoma.

The detection of DNA methylation in primary tumor tissues could be relevant for early stratification of aggressive renal cell carcinomas (RCCs) as a basis for future personalized adjuvant therapy. Methylated TCGA KIRC based candidate CpG loci in INA, NHLH2, and THBS4 that are possibly associated with RCC metastasis were evaluated by pyrosequencing in 154 paired normal adjacent and primary tumor tissues, as well as in 202 metastatic tissues. Statistical analysis was carried out by bivariate logistic regression for group comparisons, log rank survival analysis, and unsupervised and supervised analysis for the classification of tumors. Increased methylation of INA, NHLH2, and THBS4 loci were significantly associated with distant metastasis in primary tumors (p < 0.05), tissue-specific hypermethylation in metastatic (p = 7.88 × 10-8, 5.57 × 10-10, 2.06 × 10-7) and tumor tissues (p = 3.72 × 10-24, 3.17 × 10-13, 1.58 × 10-19), and shortened progression free survival in patients (p = 0.03). Combined use of CpG site-specific methylation permits the discrimination of tissues with metastatic disease and reveals a significant contribution of CpG sites in all genes to the statistical classification model. Thus, metastasis in RCC is significantly associated with methylation alterations in INA, NHLH2, and THBS4 loci, providing independent information for the potential early detection of aggressive renal cancers as a rationale for stratifying patients to adjuvant therapies.

Homeostatic and pathogenic roles of PI3Kδ in the human immune system.

Phosphoinositide 3-kinase delta (PI3Kδ) mediates signaling transduction downstream of diverse immune receptors, including the T cell receptor (TCR), the B cell receptor (BCR), costimulatory molecules and cytokine receptors. Our understanding of the role of PI3Kδ in the immune system comes primarily from mice, and especially from the consequences of pharmacological inhibition of PI3Kδ in mouse models of human disease as well as the consequences of genetic manipulation, resulting in hyperactivation or loss of PI3Kδ function. In case of humans, in vitro studies with PI3Kδ-specific inhibitors, the consequences of treatment of hematologic malignancies with the PI3Kδ-specific inhibitor idelalisib and primary immunodeficiency disorders due to germline variants hyper- or underactivating PI3Kδ provide most of our knowledge on the role of PI3Kδ in immunity and immune regulation. In this review, we summarize the physiological and pathophysiological roles of PI3Kδ in the human immune system, focusing on immunodeficiency due to defects in PI3Kδ signaling and especially on the recently reported cases with mutations resulting in loss of PI3Kδ activity.

Age-, tumor-, and metastatic tissue-associated DNA hypermethylation of a T-box brain 1 locus in human kidney tissue.

BACKGROUND: While a considerable number of tumor-specific hypermethylated loci have been identified in renal cell cancer (RCC), DNA methylation of loci showing successive increases in normal, tumoral, and metastatic tissues could point to genes with high relevance both for the process of tumor development and progression. Here, we report that DNA methylation of a locus in a genomic region corresponding to the 3'UTR of the transcription factor T-box brain 1 (TBR1) mRNA accumulates in normal renal tissues with age and possibly increased body mass index. Moreover, a further tissue-specific increase of methylation was observed for tumor and metastatic tissue samples. RESULTS: Biometric analyses of the TCGA KIRC methylation data revealed candidate loci for age-dependent and tumor-specific DNA methylation within the last exon and in a genomic region corresponding to the 3'UTR TBR1 mRNA. To evaluate whether methylation of TBR1 shows association with RCC carcinogenesis, we measured 15 tumor cell lines and 907 renal tissue samples including 355 normal tissues, 175 tissue pairs of normal tumor adjacent and corresponding tumor tissue as well 202 metastatic tissues samples of lung, bone, and brain metastases by the use of pyrosequencing. Statistical evaluation demonstrated age-dependent methylation in normal tissue (R = 0.72, p < 2 × 10-16), association with adiposity (P = 0.019) and tumor-specific hypermethylation (P = 6.1 × 10-19) for RCC tissues. Comparison of tumor and metastatic tissues revealed higher methylation in renal cancer metastases (P = 2.65 × 10-6). CONCLUSIONS: Our analyses provide statistical evidence of association between methylation of TBR1 and RCC development and disease progression.

DNA methylation of sarcosine dehydrogenase (SARDH) loci as a prognosticator for renal cell carcinoma.

DNA methylation plays an important role in the genesis and progression of tumor diseases. To identify new DNA methylation markers possibly associated with the clinical characteristics of renal cell carcinoma (RCC), we investigated loci in the sarcosine dehydrogenase (SARDH) gene. SARDH is involved in the metabolism of the glycine­derivative sarcosine and is closely linked through a functional control loop. Statistical evaluation of methylation data and clinical characteristics of patients showed that kidney tumors with clinically aggressive features such as a high tumor stage, positive lymph nodes, distant metastases or a previously advanced tumor status exhibited significantly lower methylation of a locus in the SARDH gene. Moreover, SARDH methylation was found to be a significant prognostic factor for recurrence­free survival in RCC patients showing statistical independence from the clinical prognosticators, grade, stage and state of metastasis. In conclusion, the methylation status of the SARDH­CGI was identified as an independent prognostic candidate marker for RCC.

Progressive Immunodeficiency with Gradual Depletion of B and CD4⁺ T Cells in Immunodeficiency, Centromeric Instability and Facial Anomalies Syndrome 2 (ICF2).

Immunodeficiency, centromeric instability and facial anomalies syndrome 2 (ICF2) is a rare autosomal recessive primary immunodeficiency disorder. So far, 27 patients have been reported. Here, we present three siblings with ICF2 due to a homozygous ZBTB24 gene mutation (c.1222 T>G, p. (Cys408Gly)). Immune deficiency in these patients ranged from late-onset combined immunodeficiency (CID) with severe respiratory tract infections and recurrent shingles to asymptomatic selective antibody deficiency. Evident clinical heterogeneity manifested despite a common genetic background, suggesting the pathogenic relevance of epigenetic modification. Immunological follow-up reveals a previously unidentified gradual depletion of B and CD4⁺ T cells in all three presented patients with transition of a common variable immunodeficiency (CVID)-like disease to late-onset-CID in one of them. Considering all previously published cases with ICF2, we identify inadequate antibody responses to vaccines and reduction in CD27⁺ memory B cells as prevalent immunological traits. High mortality among ICF2 patients (20%) together with the progressive course of immunodeficiency suggest that hematopoietic stem cell transplantation (HSCT) should be considered as a treatment option in due time.

A Splice Site Variant of CDK12 and Breast Cancer in Three Eurasian Populations.

CDK12 is a member of the cyclin-dependent kinase family that acts as regulator of DNA damage response gene expression. A c.1047-2A>G splice site variant of the CDK12 gene was recently reported to strongly associate with hereditary breast and ovarian cancer in patients of Tatar ethnic origin. To gain more insight into the potential risk and the population spread of the c.1047-2A>G variant, we have genotyped three breast cancer case-control series of Tatar, Bashkir and Kazakh ethnicity. We identified c.1047-2A>G in 6/155 cases and 12/362 controls of Tatar ancestry, 0/96 cases and 9/189 controls of Bashkir ancestry, and 1/131 cases and 0/154 controls of Kazakh ancestry (Mantel-Haenszel odds ratio 0.72, 95% CI 0.30-1.70, p = 0.45). Consistent with the absence of a large effect, bioinformatic analyses predicted that c.1047-2A>G modulates alternative splicing of a NAGNAG sequence rather than constituting a loss-of-function allele, and RT-PCR analyses of c.1047-2A>G heterozygous lymphocytes verified the usage of the predicted alternative acceptor site. Our study confirms a high prevalence of CDK12*c.1047-2A>G in the Tatar and Bashkir population but excludes a role as a clinically actionable high-risk breast cancer mutation.

DNA methylation of neural EGFL like 1 (NELL1) is associated with advanced disease and the metastatic state of renal cell cancer patients.

Recent studies have shown that NELL1 expression is silenced epigenetically in human renal cell cancer (RCC) tissues and in RCC cell lines. However, it remains unknown whether NELL1 promoter methylation observed in clinical specimens might be associated with the clinicopathology or survival of patients with RCC. We analyzed NELL1 DNA methylation in tissues from patients with RCC and in adjacent normal renal tissues. In addition, we evaluated NELL1 methylation in cell lines derived from different urogenital tumors (prostate cancer, urothelial cancer and RCC). We performed regression analyses to determine whether NELL1 methylation is associated with clinicopathological parameters and recurrence­free survival (RFS). This cross­sectional study included 98 patients with RCC and 63 paired tumor and adjacent normal tissue samples. We analyzed a locus in the intron 1 region of NELL1 with pyrosequencing. We performed in silico analysis of NELL1 methylation in the TCGA Kidney Renal Clear Cell Carcinoma (KIRC) data set (n=284 patients), which served as a validation study. Statistical analyses were performed with the two­sided paired t­test for paired tumor and adjacent normal samples. We used logistic regression for subgroup comparisons and Cox regression for RFS comparisons. The mean methylation level was 6.8% higher in RCC tissues compared to paired adjacent normal tissues (paired t­test, P<0.001). Methylation levels in RCC were associated with advanced disease (P=0.002), the presence of distant metastases (P=0.004), and shorter RFS (P=0.035, HR: 4.15). In silico validation with TCGA KIRC data for adjacent loci also demonstrated that high relative methylation levels were associated with adverse clinicopathology and shortened RFS. Our results suggest that NELL1 methylation contributes to RCC disease progression. This finding could provide a clinical marker to complement recent functional analyses in tumor models.