Polymorphic variations in the FANCA gene in high-risk non-BRCA1/2 breast cancer individuals from the French Canadian population (original) (raw)

Mutational analysis of FANCL , FANCM and the recently identified FANCI suggests that among the 13 known Fanconi Anemia genes, only FANCD1/BRCA2 plays a major role in high-risk breast cancer predisposition

Carcinogenesis, 2009

Fanconi Anemia (FA) is a rare recessive syndrome characterized by cellular hypersensitivity to DNA-cross-linking agents. To date, 13 FA complementation groups have been described and all 13 genes associated to each of these groups have been currently identified. Three of the known FA genes are also high-risk (FANCD1/ BRCA2) or moderate-risk (FANCN/PALB2 and FANCJ/BRIP1) breast cancer susceptibility genes, which makes all members of the FA pathway particularly attractive breast cancer candidate genes. Most FA genes have been screened for mutations in breast cancer families negative for BRCA1/2 mutations but the role of FANCL, FANCM and the recently identified FANCI has not been evaluated to date. This fact and novel data sustaining greater functional relevance of the three genes within the FA pathway prompted us to scrutinize all coding sequences and splicing sites of FANCI, FANCL and FANCM in 95 BRCA1/2-negative index cases from Spanish high-risk breast cancer families. We identified 68 sequence variants of which 24 were coding and 44 non-coding. Six exonic and 26 non-coding variants had not been described previously. None of the coding changes caused clearly pathogenic changes and computational analysis of all non-described intronic variants did not revealed major impact in splicing. With the present study, all known FA genes have been evaluated within the context of breast cancer high-risk predisposition. Our results rule out a major role of FANCI, FANCL and FANCM in familial breast cancer susceptibility, suggesting that among the 13 known FA genes, only FANCD1/BRCA2 plays a major role in high-risk breast cancer predisposition.

FANCD2 and BRCA1 have differential expression among the FA-BRCA genes in primary breast cancer

2020

The molecular pathways of DNA repair in tumors may play a role in tailoring patient therapy. The Fanconi anemia DNA repair pathway operates in the repair of DNA interstrand crosslink induced by several chemotherapeutic drugs. In this study we evaluated the expression of Fanconi anemia DNA repair genes ( FANCA , C , D2, F, BRCA1 and PALB2) in 46 primary breast tumors and ten non-compromised breast samples, by Real-Time Quantitative Reverse Transcription PCR, and to correlated gene expression with breast cancer subtypes and clinico-pathological parameters. Tumor samples were classified in subtypes based on immunohistochemistry markers, and clinico-pathological parameters were obtained from the medical reports. FANCD2 was twice more expressed in tumors than in the non-compromised group (p= 0.02). BRCA1 showed a differential expression in the luminal group, three times less expressed in Luminal-B than in Luminal-A group (p= 0.01). In conclusion, the higher level of expression of FANCD2 ...

The Fanconi anemia family of genes and its correlation with breast cancer susceptibility and breast cancer features

Breast Cancer Research and Treatment, 2009

Fanconi anemia (FA) family of proteins participates in the DNA repair pathway by homologous recombination, and it is currently formed by 13 genes. Some of these proteins also confer susceptibility to hereditary breast and ovarian cancer (HBOC), since FANCD1 is the BRCA2 breast cancer susceptibility gene, and FANCN/PALB2 and FANCJ/BRIP1 explain 2% of non-BRCA1/2 HBOC families. Thus, there is an important connection between FA and BRCA pathways. In a previous case–control association study analysing FANCA, FANCD2 and FANCL, we reported an association between FANCD2 and sporadic breast cancer (BC) risk (OR = 1.35). In order to know whether variants in other FA genes could also be involved in this association, we have extended our study with the rest of FA genes and some others implicated in the BRCA pathway. We have also analyzed the correlation with survival, nodal metastasis and hormonal receptors (ER− and PR−). A total of 61 SNPs in ten FA genes (FANC-B, -C, -D1, -E, -F, -G, -I, -J, -M, -N) and five FA related genes (ATM, ATR, BRCA1, H2AX and USP1) were studied in a total of 547 consecutive and nonrelated sporadic BC cases and 552 unaffected controls from the Spanish population. Association analyses reported marginal statistically significant results with the minor allele of intronic SNPs in three genes: BRCA1, BRCA2/FANCD1, and ATM. Survival association with SNPs on FANCC and BRCA2/FANCD1 genes were also reported. Sub-group analyses revealed associations between SNPs on FANCI and ATM and nodal metastasis status and between FANCJ/BRIP1 and FANCN/PALB2 and PR− status.

Lack of large genomic deletions in BRIP1, PALB2, and FANCD2 genes in BRCA1/2 negative familial breast cancer

Breast Cancer Research and Treatment, 2009

Breast cancer (BC) is the most common malignancy in women worldwide. It is estimated that 5-10% of all BC cases may be caused by germline mutations in breast cancer susceptibility genes . BRCA1 and BRCA2 are the major known BC susceptibility genes accounting for *16% of the familial BC cases [2]. Other BC susceptibility genes include TP53 [16], PTEN [15], ATM [24], LKB1/STK11 [8], CHEK2 [28], BRIP1/FANCJ [27], and PALB2/FANCN [22]. However to date, the majority of familial BC cases can not be attributed to mutations in one of the known susceptibility genes. The discovery of the breast cancer susceptibility gene BRCA2 as the gene defective in the Fanconi anemia (FA)-D1 complementation group [11], the identification of BRIP1 (BRCA1 Interacting Protein) [3, 12, 13] and PALB2 (Partner And Localizer of BRCA2) as the genes responsible for the FA-J and FA-N complementation groups, respectively, established a clear link between breast cancer susceptibility and FA. Fanconi anemia (FA) is a recessively inherited chromosomal instability syndrome with autosomal or X-linked mode of inheritance, and is characterized by an increased susceptibility to several forms of malignancies . The disease is caused by mutations in one of the 13 genes so far identified . The FA gene products interact in a common pathway whereby most of the proteins (FANCA-L, and -M) form a multiprotein complex that is required for the monoubiquitination of FANCD2 and FANCI. However, this modification step is not influenced by FANCD1 (BRCA2), FANCJ (BRIP1), or FANCN (PALB2), and hence these proteins seem to act downstream of this process. FANCD2 and FANCI are thought to form a protein complex (ID complex), which translocates to DNA damage sites where it co-localizes with the downstream FA proteins, BRCA2/FANCD1, BRIP1/FANCJ, and PALB2/FANCN and other proteins that are involved in the recognition and repair of DNA damage, such as BRCA1, ATM, NBS, and RAD51 .

A rare FANCA gene variation as a breast cancer susceptibility allele in an Iranian population

Molecular Medicine Reports, 2017

Fanconi Anemia (FA) is an autosomal recessive syndrome characterized by congenital abnormalities, progressive bone marrow failure and Fanconi anemia complementation group A (FANCA) is also a potential breast and ovarian cancer susceptibility gene. A novel allele with tandem duplication of 13 base pair sequence in promoter region was identified. To investigate whether the 13 base pair sequence of tandem duplication in promoter region of the FANCA gene is of high penetrance in patients with breast cancer and to determine if the presence of the duplicated allele was associated with an altered risk of breast cancer, the present study screened DNA in blood samples from 304 breast cancer patients and 295 normal individuals as controls. The duplication allele had a frequency of 35.4 and 21.2% in patients with breast cancer and normal controls, respectively. There was a significant increase in the frequency of the duplication allele in patients with familial breast cancer compared with controls (45.1%, P=0.001). Furthermore, the estimated risk of breast cancer in individuals with a homozygote [odds ratio (OR), 4.093; 95% confidence intervals (CI), 1.957-8.561] or heterozygote duplicated genotype (OR, 3.315; 95% CI, 1.996-5.506) was higher compared with the corresponding normal homozygote genotype. In conclusion, the present study indicated that the higher the frequency of the duplicated allele, the higher the risk of breast cancer. To the best of our knowledge, the present study is the first to report FANCA gene duplication in patients with breast cancer.

Mutational analysis of the breast cancer susceptibility gene BRIP1 /BACH1/FANCJ in high-risk non- BRCA1/BRCA2 breast cancer families

Journal of Human Genetics, 2008

The BRIP1 gene encodes a helicase interacting with BRCA1, which contributes to BRCA1-associated DNA repair function. Germ-line BRIP1 mutations affecting the helicase domain activity have been identified in early onset breast cancer patients. In addition, BRIP1 was recently identified as deficient in Fanconi anemia (FA) complementation group J. Given the growing evidence now linking BRCA1, BRCA2, and the FA pathway, as well as the involvement of FA proteins (BRCA2/FANCD1 and PALB2/FANCN) in breast cancer susceptibility, we sought to evaluate the contribution of FANCJ gene alterations regarding breast cancer susceptibility among our cohort of 96 breast cancer individuals from high-risk non-BRCA1/2 French Canadian families. No deleterious mutation, exon deletion, or retention of intronic portions could be identified. However, extensive analysis of the promoter and whole exonic and flanking intronic regions of FANCJ led to the identification of 42 variants, including 22 novel variants not previously reported, four of which were located in the promoter region. Transcription factors analysis revealed a potential involvement of FANCJ promoter variants in regulation of FANCJ expression, and reporter gene assays were performed. The allelic frequency was assessed in a cohort of 73 unaffected French Canadian individuals, and haplotype analysis and tagging single nucleotide polymorphism (SNP) identification were also performed. Although our study unlikely involves FANCJ as a high-risk predisposition gene in non-BRCA1/2 high-risk French Canadian families, the possible association of FANCJ missense variants with phenotypes associated with FA, such as childhood cancer, cannot be excluded.

Two truncating variants in FANCC and breast cancer risk

Scientific Reports, 2019

Fanconi anemia (FA) is a genetically heterogeneous disorder with 22 disease-causing genes reported to date. In some FA genes, monoallelic mutations have been found to be associated with breast cancer risk, while the risk associations of others remain unknown. The gene for FA type C, FANCC, has been proposed as a breast cancer susceptibility gene based on epidemiological and sequencing studies. We used the Oncoarray project to genotype two truncating FANCC variants (p.R185X and p.R548X) in 64,760 breast cancer cases and 49,793 controls of European descent. FANCC mutations were observed in 25 cases (14 with p.R185X, 11 with p.R548X) and 26 controls (18 with p.R185X, 8 with p.R548X). There was no evidence of an association with the risk of breast cancer, neither overall (odds ratio 0.77, 95%CI 0.44–1.33, p = 0.4) nor by histology, hormone receptor status, age or family history. We conclude that the breast cancer risk association of these two FANCC variants, if any, is much smaller than...

The FANCM:p.Arg658* truncating variant is associated with risk of triple-negative breast cancer

npj Breast Cancer

Breast cancer is a common disease partially caused by genetic risk factors. Germline pathogenic variants in DNA repair genes BRCA1, BRCA2, PALB2, ATM, and CHEK2 are associated with breast cancer risk. FANCM, which encodes for a DNA translocase, has been proposed as a breast cancer predisposition gene, with greater effects for the ER-negative and triple-negative breast cancer (TNBC) subtypes. We tested the three recurrent protein-truncating variants FANCM:p.Arg658*, p.Gln1701*, and p.Arg1931* for association with breast cancer risk in 67,112 cases, 53,766 controls, and 26,662 carriers of pathogenic variants of BRCA1 or BRCA2. These three variants were also studied functionally by measuring survival and chromosome fragility in FANCM−/− patient-derived immortalized fibroblasts treated with diepoxybutane or olaparib. We observed that FANCM:p.Arg658* was associated with increased risk of ER-negative disease and TNBC (OR = 2.44, P = 0.034 and OR = 3.79; P = 0.009, respectively). In a coun...

Mutation analysis of FANCD2, BRIP1/BACH1, LMO4 and SFN in familial breast cancer

Breast cancer research : BCR, 2005

Mutations in known predisposition genes account for only about a third of all multiple-case breast cancer families. We hypothesized that germline mutations in FANCD2, BRIP1/BACH1, LMO4 and SFN may account for some of the unexplained multiple-case breast cancer families. The families used in this study were ascertained through the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab). Denaturing high performance liquid chromatography (DHPLC) analysis of the coding regions of these four genes was conducted in the youngest affected cases of 30 to 267 non-BRCA1/2 breast cancer families. In addition, a further 399 index cases were also screened for mutations in two functionally significant regions of the FANCD2 gene and 253 index cases were screened for two previously reported mutations in BACH1 (p. P47A and p. M299I). DHPLC analysis of FANCD2 identified six silent exonic variants, and a large number of intronic variants, which tagged two common hapl...

Analysis of the Novel Fanconi Anemia GeneSLX4/FANCPin Familial Breast Cancer Cases

Human Mutation, 2012

SLX4/FANCP is a recently discovered novel disease gene for Fanconi anemia (FA), a rare recessive disorder characterized by chromosomal instability and increased cancer susceptibility. Three of the 15 FA genes are breast cancer susceptibility genes in heterozygous mutation carriers-BRCA2, PALB2, and BRIP1. To investigate if defects in SLX4 also predispose to breast cancer, the gene was sequenced in a cohort of 729 BRCA1/BRCA2negative familial breast cancer cases. We identified a single splice site mutation (c.2013+2T>A), which causes a frameshift by skipping of exon 8. We also identified 39 missense variants, four of which were selected for functional testing in a Mitomycin C-induced growth inhibition assay, and appeared indistinguishable from wild type. Although this is the first study that describes a truncating SLX4 mutation in breast cancer patients, our data indicate that germline mutations in SLX4 are very rare and are unlikely to make a significant contribution to familial breast cancer.