FANCJ DNA helicase is recruited to the replisome by AND-1 to ensure genome stability.

FANCJ, a DNA helicase linked to Fanconi anemia and frequently mutated in cancers, counteracts replication stress by dismantling unconventional DNA secondary structures (such as G-quadruplexes) that occur at the DNA replication fork in certain sequence contexts. However, how FANCJ is recruited to the replisome is unknown. Here, we report that FANCJ directly binds to AND-1 (the vertebrate ortholog of budding yeast Ctf4), a homo-trimeric protein adaptor that connects the CDC45/MCM2-7/GINS replicative DNA helicase with DNA polymerase α and several other factors at DNA replication forks. The interaction between FANCJ and AND-1 requires the integrity of an evolutionarily conserved Ctf4-interacting protein (CIP) box located between the FANCJ helicase motifs IV and V. Disruption of the CIP box significantly reduces FANCJ association with the replisome, causing enhanced DNA damage, decreased replication fork recovery and fork asymmetry in cells unchallenged or treated with Pyridostatin, a G-quadruplex-binder, or Mitomycin C, a DNA inter-strand cross-linking agent. Cancer-relevant FANCJ CIP box variants display reduced AND-1-binding and enhanced DNA damage, a finding that suggests their potential role in cancer predisposition.

Extended panel testing in ovarian cancer reveals BRIP1 as the third most important predisposition gene.

PURPOSE: The prevalence of germline pathogenic variants (PVs) in homologous recombination repair (HRR) and Lynch syndrome (LS) genes in ovarian cancer (OC) is uncertain. METHODS: An observational study reporting the detection rate of germline PVs in HRR and LS genes in all OC cases tested in the North West Genomic Laboratory Hub between September 1996 and May 2024. Effect sizes are reported using odds ratios (ORs) and 95% confidence intervals (95% CI) for unselected cases tested between April 2021 and May 2024 versus 50,703 controls from the Breast Cancer Risk after Diagnostic Gene Sequencing study. RESULTS: 2934 women were tested for BRCA1/2 and 433 (14.8%) had a PV. In up to 1572 women tested for PVs in non-BRCA1/2 HRR genes, detection rates were PALB2 = 0.8%, BRIP1 = 1.1%, RAD51C = 0.4% and RAD51D = 0.4%. In 940 unselected cases, BRIP1 (OR = 8.7, 95% CI 4.6-15.8) was the third most common OC predisposition gene followed by RAD51C (OR = 8.3, 95% CI 3.1-23.1), RAD51D (OR = 6.5, 95% CI 2.1-19.7), and PALB2 (OR = 3.9, 95% CI 1.5-10.3). No PVs in LS genes were detected in unselected cases. CONCLUSION: Panel testing in OC resulted in a detection rate of 2% to 3% for germline PVs in non-BRCA1/2 HRR genes, with the largest contributor being BRIP1. Screening for LS in unselected cases of OC is unnecessary.

BRIP1 and BRIP2 maintain root meristem by affecting auxin-mediated regulation.

MAIN CONCLUSION: This study reveals that mutations in BRIP1/2 subunits of the BAS complex disrupt root meristem development by decreasing PIN genes expression, affecting auxin transport, and downregulating essential root genes PLT. Switch defective/sucrose non-fermentable (SWI/SNF) chromatin remodeling complexes play vital roles in plant development. BRAHMA-interacting proteins1 (BRIP1) and BRIP2 are subunits of BRAHMA (BRM)-associated SWI/SNF complex (BAS) in plants; however, their role and underlying regulatory mechanism in root development are still unknown. Here, we show that brip1 brip2 double mutants have a significantly shortened root meristem and an irregular arrangement in a portion of the root stem cell niche. The mutations in BRIP1 and BRIP2 cause decreased expression of the PIN-FORMED (PIN) genes, which in turn reduces the transport of auxin at the root tip, leading to the disruption of the accurate establishment of normal auxin concentration gradients in the stem cells. Chromatin immunoprecipitation (ChIP) experiments indicated that BRIP1 and BRIP2 directly bind to the PINs. Furthermore, we found a significant down-regulation in the expression of key root development genes, PLETHORA (PLT), in brip1 brip2. The brip1 brip2 plt1 plt2 quadruple mutations do not show further exacerbation in the short-root phenotype compared to plt1 plt2 double mutants. Using a dexamethasone (DEX)-inducible PLT2 transgenic line, we showed that acute overexpression of PLT2 partially rescues root meristem defects of brip1 brip2, suggesting that BRIP1 and BRIP2 act in part through the PLT1/2 pathway. Taken together, our results identify the critical role and the underlying mechanism of BRIP1/2 in maintaining the development of root meristem through the regulation of auxin output and expression of PLTs.

Patterns of care and outcomes of risk reducing surgery in women with pathogenic variants in non-BRCA and Lynch syndrome ovarian cancer susceptibility genes.

OBJECTIVES: Guidelines recommend risk-reducing bilateral salpingo-oophorectomy (RRSO) for women with pathogenic variants of non-BRCA and Lynch syndrome-associated ovarian cancer susceptibility genes. Optimal timing and findings at the time of RRSO for these women remains unclear. We sought to characterize practice patterns and frequency of occult gynecologic cancers for these women at our two institutions. METHODS: Women with germline ovarian cancer susceptibility gene pathogenic variants who underwent RRSO between 1/2000-9/2019 were reviewed in an IRB-approved study. All patients were asymptomatic with no suspicion for malignancy at time of RRSO. Clinico-pathologic characteristics were extracted from the medical records. RESULTS: 26 Non-BRCA (9 BRIP1, 9 RAD51C, and 8 RAD51D) and 75 Lynch (36 MLH1, 18 MSH2, 21 MSH6) pathogenic variants carriers were identified. Median age at time of RRSO was 47. There were no occurrences of occult ovarian or fallopian tube cancer in either group. Two patients (3%) in the Lynch group had occult endometrial cancer. Median follow up was 18 and 35 months for non-BRCA and Lynch patients, respectively. No patient developed primary peritoneal cancer upon follow up. Post-surgical complications occurred in 9/101 (9%) of patients. Hormone replacement therapy (HRT) was rarely used despite reported post-menopausal symptoms in 6/25 (23%) and 7/75 (37%) patients, respectively. CONCLUSIONS: No occult ovarian or tubal cancers were observed in either group. No recurrent or primary gynecologic-related cancers occurred upon follow-up. Despite frequent menopausal symptoms, HRT use was rare. Both groups experienced surgical complications when hysterectomy and/or concurrent colon surgery was performed suggesting concurrent surgeries should only be performed when indicated.

Multimolecular characteristics and role of BRCA1 interacting protein C-terminal helicase 1 (BRIP1) in human tumors: a pan-cancer analysis.

BACKGROUND: The aberrant expression of BRIP1 was associated with several cancers; however, the panoramic picture of BRIP1 in human tumors remains unclear. This study aims to explore the pan-cancerous picture of the expression of BRIP1 across 33 human cancers. METHODS: Based on the data from TCGA and GTEx, a series of bioinformatic analyses were applied to systematically explore the genetic landscape and biologic function of BRIP1 in 33 human tumors. RESULTS: We observed prognosis-related differential BRIP1 expressions between various carcinomas and the corresponding normal tissues. "Basal transcription factors," "homologous recombination," "nucleotide excision repair," and DNA metabolism pathways may play a role in the functional mechanisms of BRIP1. Patients with uterine corpus endometrial carcinoma presented with the highest alteration frequency of BRIP1 (nearly 10%). Single-nucleotide and copy number variations of BRIP1 were noticed in multiple cancers, and the expression of BRIP1 is significantly regulated by copy number variation in breast invasive carcinoma and lung squamous cell carcinoma. BRIP1 expression is negatively correlated with the DNA methylation levels in many tumors and is associated with the activation of apoptosis, cell cycle, DNA damage response, and inhibition of hormone ER and RNS/MARK signaling pathways. Moreover, a positive correlation was observed between BRIP1 expression and the immune infiltration levels of cancer-associated fibroblasts and CD8+ T cells in lung adenocarcinoma. CONCLUSION: Our pan-cancer analysis of BRIP1 provides a valuable resource for understanding the multimolecular characteristics and biological function of BRIP1 across human cancers.

Association of BARD1 and BRIP1 Gene Polymorphisms with the Risk of Uveal Melanoma.

Considering the limited information about the role of hereditary predisposition to the development of uveal melanoma, we have performed an analysis of the frequencies of BARD1 (rs1048108, rs2229571, rs2070094) and BRIP1 (rs4986764) gene polymorphisms in patients with uveal melanoma and benign choroidal nevus in comparison with healthy volunteers (control). It has been found that the minor alleles of BRIP1 rs4986764 and BARD1 rs2070094 polymorphisms, as well as the homozygosity of T allele at the BARD1 rs1048108 locus are common genetic markers for the predisposition to uveal melanoma and benign choroidal nevus, while the homozygous genotype GG for the BARD1 rs2229571 polymorphism is a specific marker for the predisposition to uveal melanoma and progressive choroidal nevus. We have also found that the heterozygous genotype at BARD1 rs1048108 polymorphic locus is a specific marker for protection against uveal melanoma and progressive choroidal nevus. Thus, our results indicate the advisability of studying polymorphisms of the BARD1 gene (rs1048108, rs2229571, and rs2070094) and the BRIP1 gene (rs4986764) in patients with uveal melanoma and progressive choroidal nevus. The obtained findings can be used for forming risk groups, prevention of uveal melanoma, and differential diagnosis of intraocular neoplasms.

Population-based Screening for Hereditary Colorectal Cancer Variants in Japan.

BACKGROUND & AIMS: Colorectal cancer (CRC) is one of the most common cancers in the world. A small proportion of CRCs can be attributed to recognizable hereditary germline variants of known CRC susceptibility genes. To better understand cancer risk, it is necessary to explore the prevalence of hereditary CRC and pathogenic variants of multiple cancer-predisposing genes in non-European populations. METHODS: We analyzed the coding regions of 27 cancer-predisposing genes in 12,503 unselected Japanese CRC patients and 23,705 controls by target sequencing and genome-wide SNP chip. Their clinical significance was assessed using ClinVar and the guidelines by ACMG/AMP. RESULTS: We identified 4,804 variants in the 27 genes and annotated them as pathogenic in 397 and benign variants in 941, of which 43.6% were novel. In total, 3.3% of the unselected CRC patients and 1.5% of the controls had a pathogenic variant. The pathogenic variants of MSH2 (odds ratio (OR) = 18.1), MLH1 (OR = 8.6), MSH6 (OR = 4.9), APC (OR = 49.4), BRIP1 (OR=3.6), BRCA1 (OR = 2.6), BRCA2 (OR = 1.9), and TP53 (OR = 1.7) were significantly associated with CRC development in the Japanese population (P-values<0.01, FDR<0.05). These pathogenic variants were significantly associated with diagnosis age and personal/family history of cancer. In total, at least 3.5% of the Japanese CRC population had a pathogenic variant or CNV of the 27 cancer-predisposing genes, indicating hereditary cancers. CONCLUSIONS: This largest study of CRC heredity in Asia can contribute to the development of guidelines for genetic testing and variant interpretation for heritable CRCs.

High detection rate from genetic testing in BRCA-negative women with familial epithelial ovarian cancer.

PURPOSE: Epithelial ovarian cancer (EOC) is associated with pathogenic variants (PVs) in homologous recombination and/or mismatch repair genes. We aimed to review the testing of women with familial EOC at our center. METHODS: Women with familial EOC (≥2 EOC in family, including index case) referred to our center between 1993 and 2021 were included. Genetic testing (BRCA/Lynch syndrome screening, exome sequencing, panel testing, 100,000 Genome Project, and NIHR BioResource genome sequencing) and clinical demographic, diagnosis, and survival data were reviewed. RESULTS: Of 277, 128 (46.2%) women were BRCA heterozygotes (BRCA1: 89, BRCA2: 39). The detection rate in BRCA-negative women was 21.8%; the most commonly affected gene was BRIP1 (5.9%). The non-BRCA detection rate was significantly higher in families with 2 affected members with EOC only (22.4%) than the families with ≥3 (11.1%) affected members (odds ratio = 9.9, 95% CI = 1.6-105.2, P = .0075). Overall, 112 different PVs in 12 homologous recombination/mismatch repair genes were detected in 150 of 277 (54.2%) unrelated women. CONCLUSION: This is the largest report of women with familial EOC undergoing wider testing to date. One-fifth of BRCA-negative women were heterozygous for a PV in a potentially actionable gene. Wider genetic testing of women with familial EOC is essential to optimize their treatment and prevention of disease in family members.

Dominant-negative pathogenic variant BRIP1 c.1045G>C is a high-risk allele for non-mucinous epithelial ovarian cancer: A case-control study.

BRIP1 is a moderate susceptibility epithelial ovarian cancer (EOC) gene. Having identified the BRIP1 c.1045G>C missense variant in a number of families with EOC, we aimed to investigate the frequency of this and BRIP1.2392C>T pathogenic variant in patients with breast cancer (BC) and/or EOC. A case-control study of 3767 cases and 2043 controls was undertaken investigating the presence of these variants using Sanger sequencing and gene panel data. Individuals with BC and/or EOC were grouped by family history. BRIP1 c.1045G>C was associated with increased risk of BC/EOC (OR = 37.7; 95% CI 5.3-444.2; P = 0.0001). The risk was highest for women with EOC (OR = 140.8; 95% CI 23.5-1723.0; P < 0.0001) and lower for BC (OR = 11.1; 95% CI 1.2-106.5; P = 0.1588). BRIP1 c.2392C>T was associated with smaller risks for BC/EOC (OR = 5.4; 95%CI 2.4-12.7; P = 0.0003), EOC (OR = 5.9; 95% CI 1.3-23.0; p = 0.0550) and BC (OR = 5.3; 95%CI 2.3-12.9; P = 0.0009). Our study highlights the importance of BRIP1 as an EOC susceptibility gene, especially in familial EOC. The variant BRIP1 c.1045G>C, rs149364097, is of particular interest as its dominant-negative effect may confer a higher risk of EOC than that of the previously reported BRIP1 c.2392C>T nonsense variant. Dominant-negative missense variants may confer higher risks than their loss-of-function counterparts.

FOXO3a Mediates Homologous Recombination Repair (HRR) via Transcriptional Activation of MRE11, BRCA1, BRIP1, and RAD50.

To test whether homologous recombination repair (HRR) depends on FOXO3a, a cellular aging model of human dermal fibroblast (HDF) and tet-on flag-h-FOXO3a transgenic mice were studied. HDF cells transfected with over-expression of wt-h-FOXO3a increased the protein levels of MRE11, BRCA1, BRIP1, and RAD50, while knock-down with siFOXO3a decreased them. The protein levels of MRE11, BRCA1, BRIP1, RAD50, and RAD51 decreased during cellular aging. Chromatin immunoprecipitation (ChIP) assay was performed on FOXO3a binding accessibility to FOXO consensus sites in human MRE11, BRCA1, BRIP1, and RAD50 promoters; the results showed FOXO3a binding decreased during cellular aging. When the tet-on flag-h-FOXO3a mice were administered doxycycline orally, the protein and mRNA levels of flag-h-FOXO3a, MRE11, BRCA1, BRIP1, and RAD50 increased in a doxycycline-dose-dependent manner. In vitro HRR assays were performed by transfection with an HR vector and I-SceI vector. The mRNA levels of the recombined GFP increased after doxycycline treatment in MEF but not in wt-MEF, and increased in young HDF comparing to old HDF, indicating that FOXO3a activates HRR. Overall, these results demonstrate that MRE11, BRCA1, BRIP1, and RAD50 are transcriptional target genes for FOXO3a, and HRR activity is increased via transcriptional activation of MRE11, BRCA1, BRIP1, and RAD50 by FOXO3a.

Germline mutations in a clinic-based series of pregnancy associated breast cancer patients.

BACKGROUND: Pregnancy-associated breast cancer (PABC) defined as breast cancer diagnosed during gestation, lactation or within 1 year after delivery, represents a truly challenging situation with significantly increasing incidence rate. The genomic background of PABC has only recently been addressed while the underlying mechanisms of the disease still remain unknown. This analysis aims to further elucidate the frequency of PABC cases attributable to genetic predisposition and identify specific cancer susceptibility genes characterizing PABC. METHODS: A comprehensive 94-cancer gene panel was implemented in a cohort of 20 PABC patients treated in our clinic and descriptive correlation was performed among the results and the patients' clinicopathological data. RESULTS: In the present study, 35% of PABC patients tested carried pathogenic mutations in two known cancer predisposition genes (BRCA1 and CHEK2). In total, 30% of the patients carried BRCA1 pathogenic variants. An additional 5% carried pathogenic variants in the CHEK2 gene. Variants of unknown/uncertain significance (VUS) in breast cancer susceptibility genes BRCA2, CHEK2 and BRIP1 were also identified in three different PABC patients (15%). Not all patients carrying germline mutations reported known family history of cancer. CONCLUSIONS: Genetic testing should be considered as an option for PABC patients since the disease is highly associated with genetic susceptibility among other predisposing factors. Germline mutation identification may further modify PABC management approach and improve the prognostic outcome.

Novel role of BRCA1 interacting C-terminal helicase 1 (BRIP1) in breast tumour cell invasion.

Breast cancer (BC) is the most common malignancy and the leading cause of death in women worldwide. Only 5%-10% of mutations in BRCA genes are associated with familial breast tumours in Eastern countries, suggesting the contribution of other genes. Using a microarray gene expression profiling study of BC, we have recently identified BRIP1 (fivefold up-regulation) as a potential gene associated with BC progression in the Omani population. Although BRIP1 regulates DNA repair and cell proliferation, the precise role of BRIP1 in BC cell invasion/metastasis has not been explored yet; this prompted us to test the hypothesis that BRIP1 promotes BC cell proliferation and invasion. Using a combination of cellular and molecular approaches, our results revealed differential overexpression of BRIP1 in different BC cell lines. Functional assays validated further the physiological relevance of BRIP1 in tumour malignancy, and siRNA-mediated BRIP1 knockdown significantly reduced BC cell motility by targeting key motility-associated genes. Moreover, down-regulation of BRIP1 expression significantly attenuated cell proliferation via cell cycle arrest. Our study is the first to show the novel function of BRIP1 in promoting BC cell invasion by regulating expression of various downstream target genes. Furthermore, these findings provide us with a unique opportunity to identify BRIP1-induced pro-invasive genes that could serve as biomarkers and/or targets to guide the design of appropriate BC targeted therapies.

Frequency of heterozygous germline pathogenic variants in genes for Fanconi anemia in patients with non-BRCA1/BRCA2 breast cancer: a meta-analysis.

PURPOSE: Germline pathogenic variants in BRCA1 (FANCD1) and BRCA2 (FANCS) do not explain all familial or sporadic cases with breast cancer. Several reports indicate a role for pathogenic variants in other genes in the Fanconi anemia/breast cancer DNA repair pathway; the strengths of these associations vary widely. Publications from 2006 through 2017 were reviewed to provide a better estimate of the role of pathogenic variants in genes in this pathway in breast cancer. METHODS: We identified cohorts and case-control reports describing heterozygous pathogenic variants in Fanconi anemia genes in breast cancer cases with high risk of a germline pathogenic variant in a non-BRCA1/2 breast cancer susceptibility gene ("familial"), and cases unselected for family history ("unselected"). Meta-analysis and meta-regression were used to estimate the frequencies of pathogenic variants in cohorts and the odds ratios (OR) in case-control studies. RESULTS: Meta-analysis of more than 100 reports of FANCN/PALB2 in familial breast cancer cases provided an overall pathogenic variant prevalence of 1.29% and an OR of 8.45. The prevalence in unselected cohorts was 0.64%, and the OR was 4.76. Pathogenic variants in FANCJ/BRIP1 had a prevalence of 0.5% in familial cases, and an OR of 1.62; their prevalence in unselected cases was 0.39%. FANCO/RAD51C, FANCP/SLX4, FANCU/XRCC2, FANCD2, and other FA-related genes all had prevalences of ≤ 0.5% among familial cases, and even lower in unselected cases. CONCLUSIONS: Heterozygous pathogenic variants in FANCN/PALB2 and possibly FANCJ/BRIP1 may account for 1-2% of familial non-BRCA1/2 breast cancer cases and 0.5-1% of unselected cases. Genetic counseling and testing may be suggested for unaffected relatives.

BRIP1 rs10744996C>A variant increases the risk of chronic obstructive pulmonary disease in the Mongolian population of northern China.

NEW FINDINGS: What is the central question of this study? What is the role of breast cancer type 1 interacting protein C-terminal helicase 1 (BRIP1) polymorphism in chronic obstructive pulmonary disease (COPD)? What is the main finding and its importance? Variant rs10744996C>A of BRIP1 increases the susceptibility of the Mongolian population to COPD. The expression of BRIP1 was significantly reduced in cigarette smoke extract-treated airway epithelial cells. ABSTRACT: Cigarette smoke is a major environmental pollutant that can induce DNA damage in humans. The development and progression of chronic obstructive pulmonary disease (COPD) are known to be related to the impairment of DNA repair. Breast cancer type 1 interacting protein C-terminal helicase 1 (BRIP1) plays an important role in DNA interstrand crosslink repair and double-strand break repair. However, the role of BRIP1 polymorphisms in COPD has not been previously described. In this study, whole genome sequencing was used to identify mutations, and single nucleotide polymorphism (SNP) genotyping was used to verify the selected SNPs. In addition the BRIP1 expression levels in 16HBE and A549 airway epithelial cells treated with or without cigarette smoke extract (CSE) were measured using western blotting and RT-qPCR. Rs10744996C>A in the 3'-untranslated region (3'UTR) of BRIP1 was then genotyped in 1296 COPD cases and 988 healthy control subjects from a Mongolian population in northern China. Significant differences in the distribution of rs10744996C>A variants between COPD and control groups (P = 0.001) were identified. Rs10744996C>A was found to be associated with significantly increased COPD risk (adjusted odds ratio = 1.60, 95% CI = 1.30-1.98, P < 0.0001). Additionally, rs10744996A genotype was found to interact with a family history of cancer and a history of x-ray exposure (P = 0.028 and 0.009, respectively). BRIP1 expression levels in 16HBE and A549 cells treated with CSE were significantly lower compared to the control treated cells. The rs10744996C>A variant of BRIP1 increased the COPD susceptibility of the Mongolian population cohort. BRIP1 mRNA and protein expression levels were significantly reduced in conjunction with CSE-induced DNA damage in 16HBE and A549 cells.

Inhibition of poly(ADP-ribose) polymerase induces synthetic lethality in BRIP1 deficient ovarian epithelial cells.

OBJECTIVE: Pathogenic variations in the homologous recombination (HR) gene, BRCA1 interacting protein C-terminal helicase 1 (BRIP1) increase the risk for ovarian cancer. PARP inhibitors (PARPi) exert a synthetic lethal effect in BRCA-mutated ovarian cancers. Effective HR requires cooperation between BRCA1 and BRIP1; therefore, BRIP1-incompetancy may predict vulnerability to synthetic lethality. Here we investigated the response of ovarian epithelial cells with defective BRIP1 function to PARPi, and compared these cells to those lacking BRCA1 activity. METHODS: We engineered Chinese Hamster ovarian (CHO) epithelial cells to express deficient BRIP1 or BRCA1, and exposed them to olaparib with or without carboplatin or cisplatin. We assessed cellular proliferation and survival; we calculated inhibitory concentrations and combination and reduction drug indices. RESULTS: BRIP1 and BRCA1 inactivation impedes HR activity, decreases cellular proliferation and compromises DNA damage recovery. Platinum agent exposure impairs cellular survival. Olaparib exposure alone decreases cell viability in BRCA1-deficient cells, although has no effect on BRIP1-deficient cells. Combining carboplatin or cisplatin with olaparib synergistically attenuates cellular survival, consistent with synthetic lethality. CONCLUSIONS: BRIP1-deficient ovarian epithelial cells exhibit defective HR, resulting in synthetic lethality when exposed to a platinum agent/PARPi combination. PARPi alone had no effect; this lack of effect may result from distinguishing molecular properties of BRIP1and/or consequences of genomic background. Our study identifies altered BRIP1 as a target for precision medicine-based therapies for ovarian cancers. This investigation supports consideration of the use of a platinum agent/PARPi combination in ovarian cancers depending upon genetic profile and genomic background.

Unraveling the molecular effect of a rare missense mutation in BRIP1 associated with inherited breast cancer.

BRIP1 is a component of the Fanconi Anemia/BRCA pathway responsible for DNA reparation via helicase activity. Some heterozygous variants in BRIP1 could contribute to Hereditary Breast Cancer through a defective DNA repair. The clinical utility of BRIP1 mutations in a familial cancer context is compromised by the conflicting interpretation of "variants of uncertain significance" (VUS). Defining the clinical significance of variants identified in genetic tests is a major challenge; therefore, studies that evaluate the biological effect of these variants are definitely necessary. To contribute to this purpose, we have characterized the variant c.550G>T of BRIP1, a missense mutation with little evidence about its pathogenicity. Since Human Splicing FinderTM predicts the creation of a new exonic splicing enhancer site we decided to perform cDNA analysis revealing that the c.550G>T mutation located in exon 6 led to an aberrant transcript causing exon 5 skipping. Our results demonstrate that the c.550G>T BRIP1 variant disrupts normal splicing, causing exon 5 skipping. Considering that the exon 5 encodes the helicase domain of BRIP1, it is expected an alteration of the function. This finding enhances the interpretation of this VUS, suggesting a potential pathogenic effect.

BRIP-1 germline mutation and its role in colon cancer: presentation of two case reports and review of literature.

BACKGROUND: Hereditary colon cancer is characterized by the inheritance of an abnormal gene mutation which predisposes to malignancy. Recent advances in genomic medicine have identified mutations in "novel" genes as conferring an increased risk of colorectal cancer. Mutations in the BRIP1 gene (BRCA1 Interacting Protein C- terminal helicase 1) are known to increase the risk of ovarian and breast cancers, but this genes association with colon cancer has not been previously reported. CASE PRESENTATION: We describe two patients with colon cancer whose tumor tissue were found to harbor BRIP1 mutations on analysis by next-generation sequencing. These patients were confirmed by analysis of lymphocytes to carry the mutation in the germline as well. CONCLUSIONS: These case reports highlight a previously unreported association of BRIP1 germline mutations with colon cancer predisposition.

Age-adjusted association of homologous recombination genes with ovarian cancer using clinical exomes as controls.

BACKGROUND: Genes in the homologous recombination pathway have shown varying results in the literature regarding ovarian cancer (OC) association. Recent case-control studies have used allele counts alone to quantify genetic associations with cancer. METHODS: A retrospective case-control study was performed on 6,182 women with OC referred for hereditary cancer multi-gene panel testing (cases) and 4,690 mothers from trios who were referred for whole-exome sequencing (controls). We present age-adjusted odds ratios (ORAdj) to determine association of OC with pathogenic variants (PVs) in homologous recombination genes. RESULTS: Significant associations with OC were observed in BRCA1, BRCA2, RAD51C and RAD51D. Other homologous recombination genes, BARD1, NBN, and PALB2, were not significantly associated with OC. ATM and CHEK2 were only significantly associated with OC by crude odds ratio (ORCrude) or by ORAdj, respectively. However, there was no significant difference between ORCrude and ORAdj for these two genes. The significant association of PVs in BRIP1 by ORCrude (2.05, CI = 1.11 to 3.94, P = 0.03) was not observed by ORAdj (0.87, CI = 0.41 to 1.93, P = 0.73). Interestingly, the confidence intervals of the two effect sizes were significantly different (P = 0.04). CONCLUSION: The lack of association of PVs in BRIP1 with OC by ORAdj is inconsistent with some previous literature and current management recommendations, highlighted by the significantly older age of OC onset for BRIP1 PV carriers compared to non-carriers. By reporting ORAdj, this study presents associations that reflect more informed genetic contributions to OC when compared to traditional count-based methods.

BRIP1 loss-of-function mutations confer high risk for familial ovarian cancer, but not familial breast cancer.

BACKGROUND: Germline mutations in the BRIP1 gene have been described as conferring a moderate risk for ovarian cancer (OC), while the role of BRIP1 in breast cancer (BC) pathogenesis remains controversial. METHODS: To assess the role of deleterious BRIP1 germline mutations in BC/OC predisposition, 6341 well-characterized index patients with BC, 706 index patients with OC, and 2189 geographically matched female controls were screened for loss-of-function (LoF) mutations and potentially damaging missense variants. All index patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germline testing and tested negative for pathogenic BRCA1/2 variants. RESULTS: BRIP1 LoF mutations confer a high OC risk in familial index patients (odds ratio (OR) = 20.97, 95% confidence interval (CI) = 12.02-36.57, P < 0.0001) and in the subgroup of index patients with late-onset OC (OR = 29.91, 95% CI = 14.99-59.66, P < 0.0001). No significant association of BRIP1 LoF mutations with familial BC was observed (OR = 1.81 95% CI = 1.00-3.30, P = 0.0623). In the subgroup of familial BC index patients without a family history of OC there was also no apparent association (OR = 1.42, 95% CI = 0.70-2.90, P = 0.3030). In 1027 familial BC index patients with a family history of OC, the BRIP1 mutation prevalence was significantly higher than that observed in controls (OR = 3.59, 95% CI = 1.43-9.01; P = 0.0168). Based on the negative association between BRIP1 LoF mutations and familial BC in the absence of an OC family history, we conclude that the elevated mutation prevalence in the latter cohort was driven by the occurrence of OC in these families. Compared with controls, predicted damaging rare missense variants were significantly more prevalent in OC (P = 0.0014) but not in BC (P = 0.0693) patients. CONCLUSIONS: To avoid ambiguous results, studies aimed at assessing the impact of candidate predisposition gene mutations on BC risk might differentiate between BC index patients with an OC family history and those without. In familial cases, we suggest that BRIP1 is a high-risk gene for late-onset OC but not a BC predisposition gene, though minor effects cannot be excluded.

Rare germline mutations in African American men diagnosed with early-onset prostate cancer.

BACKGROUND: African Americans have both a higher incidence of prostate cancer and greater disease-specific mortality compared with non-Hispanic whites. Historically, the investigation of the contribution of rare genetic variants to prostate cancer in African American men has been hampered by low participation in large genetic studies, particularly those focused on early-onset and familial disease. METHODS: We sequenced 160 genes purported to be involved in carcinogenic pathways in germline DNA samples collected from 96 African American men diagnosed with early-onset prostate cancer (≤55 years at diagnosis). REVEL software was used to determine the pathogenic potential of observed missense variants. RESULTS: We observed three protein-truncating mutations, one in BRCA2 and two in BRIP1 in three African American men diagnosed with early-onset prostate cancer. Furthermore, we observed five rare, mostly private, missense variants among four genes (BRCA1, BRCA2, PMS2, and ATM) that were predicted to be deleterious and hence likely pathogenic in our patient sample. CONCLUSIONS: Protein-truncating mutations in BRCA2 and BRIP1 were discovered in African American men diagnosed with early-onset prostate cancer. Further study is necessary to determine the role of rare, missense variants to prostate cancer incidence, and progression in this group of high-risk men.