Detection of somatic mosaicism and classification of Fanconi anemia patients by analysis of the FA/BRCA pathway

Blood ◽  
2005 ◽  
Vol 105 (3) ◽  
pp. 1329-1336 ◽  
Author(s):  
Jean Soulier ◽  
Thierry Leblanc ◽  
Jérôme Larghero ◽  
Hélène Dastot ◽  
Akiko Shimamura ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Somatic Mosaicism ◽  
Chromosome Breakage ◽  
Peripheral Blood Lymphocytes ◽  
Specific Analysis ◽  
Number Of Patients ◽  
Chromosome Fragility

AbstractFanconi anemia (FA) is characterized by congenital abnormalities, bone marrow failure, chromosome fragility, and cancer susceptibility. Eight FA-associated genes have been identified so far, the products of which function in the FA/BRCA pathway. A key event in the pathway is the monoubiquitination of the FANCD2 protein, which depends on a multiprotein FA core complex. In a number of patients, spontaneous genetic reversion can correct FA mutations, leading to somatic mosaicism. We analyzed the FA/BRCA pathway in 53 FA patients by FANCD2 immunoblots and chromosome breakage tests. Strikingly, FANCD2 monoubiquitination was detected in peripheral blood lymphocytes (PBLs) in 8 (15%) patients. FA reversion was further shown in these patients by comparison of primary fibro-blasts and PBLs. Reversion was associated with higher blood counts and clinical stability or improvement. Once constitutional FANCD2 patterns were determined, patients could be classified based on the level of FA/BRCA pathway disruption, as “FA core” (upstream inactivation; n = 47, 89%), FA-D2 (n = 4, 8%), and an unidentified downstream group (n = 2, 4%). FA-D2 and unidentified group patients were therefore relatively common, and they had more severe congenital phenotypes. These results show that specific analysis of the FA/BRCA pathway, combined with clinical and chromosome breakage data, allows a comprehensive characterization of FA patients.

scholarly journals Cytogenetic diepoxybutane sensitivity in Serbian children with Fanconi anemia

2006 ◽  
Vol 58 (4) ◽  
pp. 215-219
Author(s):  
Sanja Cirkovic ◽  
Marija Guc-Scekic ◽  
Dragana Vujic ◽  
D. Micic
Keyword(s):  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Alkylating Agents ◽  
Chromosome Breakage ◽  
Child Health Care ◽  
Bone Marrow Failure Syndromes ◽  
Mother And Child Health ◽  
Mother And Child ◽  
And Child Health

Fanconi anemia (FA) is an inherited disorder with aplastic anemia, cancer susceptibility, and hypersensitivity to alkylating agents such as diepoxybutane (DEB). The DEB test is used to screen for FA among patients with bone marrow failure syndromes (BMFS). From February of 2004 to May of 2006, 29 children with BMFS were diagnosed and treated at the Mother and Child Health Care Institute of Serbia (MCHIS). In the examined group, five out of 29 patients (17.2%) were found to have increased DEB-induced chromosome breakage (0.58-2.15 vs. 0.00-0.20 breaks/cell; p<0.001) with no overlap. Our results suggest the importance of this analysis for differential diagnosis and adequate therapy of FA among patients with BMFS.

Unexpected Fanconi Anemia Diagnosis in Patients with Bone Marrow Failure.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1056-1056
Author(s):  
Fernando O. Pinto ◽  
Thierry Leblanc ◽  
Gwenaelle Le Roux ◽  
Helene Dastot ◽  
Moema Santos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Clinical Features ◽  
Fanconi Anemia ◽  
Bone Marrow Failure ◽  
Somatic Mosaicism ◽  
Chromosome Breakage ◽  
Large Set ◽  
Chromosomal Breakage ◽  
Group A

Abstract Early diagnosis of Fanconi Anemia (FA) in patients with bone marrow failure is critical for optimal clinical management. However, the remarkably high clinical variability and the potential emergence of revertant hematopoietic cells (somatic mosaicism) can obscure and delay the diagnosis of FA. Here we addressed FA diagnosis in a prospective series of adult and pediatric patients who presented with bone marrow failure without clear overall clinical picture of FA. Sixty-six patients were classified into three groups: (1) bone marrow failure likely to be congenital, based on dysmorphic features or a family history [n=18], (2) aplastic anemia likely to be idiopathic [n=32], (3) patients with intermediate clinical features not classified into the former groups [n=16]. Of note, FA patients with typical clinical features were not included in the present study. FA diagnosis was evaluated using chromosome breakage test and FANCD2 immunoblot in PHA-stimulated-PBL. In addition, skin primary fibroblasts were analysed in order to overcome potential hematopoietic FA reversion. For that purpose, and considering that chromosome breakage tests are barely efficient in fibroblasts, we used FANCD2 immunoblot and also developped a new flow cytometry test based on MMC-sensitivity in fibroblasts (to detect downstream FA/BRCA groups). Using these approaches, we detected FA in 4 previously undiagnosed patients: a 35-years old patient from the congenital-like group; a 10-years old patient presenting as an idiopathic aplastic anemia without any FA signs; and two patients from the intermediate group: a 10-years old patient with an isolated thrombocytopenia, and a 50-years old patient presenting with pancytopenia/MDS and complete hematopoietic reversion. Importantly, FA diagnosis was definitely excluded in all other patients. In conclusion, we could identify a few unexpected FA cases in a series of patients with bone marrow failure. Therefore, the comprehensive use of a large set of tests is useful for accurate FA diagnosis. Classical chromosomal breakage tests in PBL appeared to be sufficient to exclude FA in idiopathic aplastic anemia, whereas fibroblast analysis can be necessary to definitely diagnose or exclude FA in other patients.

scholarly journals Fanconi Anemia FANCG Protein in Mitigating Radiation- and Enzyme-Induced DNA Double-Strand Breaks by Homologous Recombination in Vertebrate Cells

2003 ◽  
Vol 23 (15) ◽  
pp. 5421-5430 ◽  
Author(s):  
Kazuhiko Yamamoto ◽  
Masamichi Ishiai ◽  
Nobuko Matsushita ◽  
Hiroshi Arakawa ◽  
Jane E. Lamerdin ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Chromosome Breakage ◽  
Breast Cancer Susceptibility ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Brca1 And Brca2 ◽  
Strand Breaks

ABSTRACT The rare hereditary disorder Fanconi anemia (FA) is characterized by progressive bone marrow failure, congenital skeletal abnormality, elevated susceptibility to cancer, and cellular hypersensitivity to DNA cross-linking chemicals and sometimes other DNA-damaging agents. Molecular cloning identified six causative genes (FANCA, -C, -D2, -E, -F, and -G) encoding a multiprotein complex whose precise biochemical function remains elusive. Recent studies implicate this complex in DNA damage responses that are linked to the breast cancer susceptibility proteins BRCA1 and BRCA2. Mutations in BRCA2, which participates in homologous recombination (HR), are the underlying cause in some FA patients. To elucidate the roles of FA genes in HR, we disrupted the FANCG/XRCC9 locus in the chicken B-cell line DT40. FANCG-deficient DT40 cells resemble mammalian fancg mutants in that they are sensitive to killing by cisplatin and mitomycin C (MMC) and exhibit increased MMC and radiation-induced chromosome breakage. We find that the repair of I-SceI-induced chromosomal double-strand breaks (DSBs) by HR is decreased ∼9-fold in fancg cells compared with the parental and FANCG-complemented cells. In addition, the efficiency of gene targeting is mildly decreased in FANCG-deficient cells, but depends on the specific locus. We conclude that FANCG is required for efficient HR-mediated repair of at least some types of DSBs.

A 20-year perspective on the International Fanconi Anemia Registry (IFAR)

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1249-1256 ◽  
Author(s):  
David I. Kutler ◽  
Bhuvanesh Singh ◽  
Jaya Satagopan ◽  
Sat Dev Batish ◽  
Marianne Berwick ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Cell Cycle Control ◽  
Univariate Analysis ◽  
Autosomal Recessive Disorder ◽  
Brca1 And Brca2 ◽  
Hematopoietic Stem ◽  
Number Of Patients ◽  
Significant Difference

Fanconi anemia (FA) is an autosomal recessive disorder characterized by cellular hypersensitivity to DNA cross-linking agents and cancer predisposition. Recent evidence for the interactions of ataxia-telangiectasia mutated protein ATM and breast cancer susceptibility proteins BRCA1 and BRCA2 (identified as FANCD1) with other known FA proteins suggests that FA proteins have a significant role in DNA repair/recombination and cell cycle control. The International Fanconi Anemia Registry (IFAR), a prospectively collected database of FA patients, allows us the unique opportunity to analyze the natural history of this rare, clinically heterogeneous disorder in a large number of patients. Of the 754 subjects in this study, 601 (80%) experienced the onset of bone marrow failure (BMF), and 173 (23%) had a total of 199 neoplasms. Of these neoplasms, 120 (60%) were hematologic and 79 (40%) were nonhematologic. The risk of developing BMF and hematologic and nonhematologic neoplasms increased with advancing age with a 90%, 33%, and 28% cumulative incidence, respectively, by 40 years of age. Univariate analysis revealed a significantly earlier onset of BMF and poorer survival for complementation group C compared with groups A and G; however, there was no significant difference in the time to hematologic or nonhematologic neoplasm development between these groups. Multivariate analysis of overall survival time shows that FANCCmutations (P = .007) and hematopoietic stem cell transplantation (P = < .0001) define a poor-risk subgroup. The results of this study of patients registered in the IFAR over a 20-year period provide information that will enable better prediction of outcome and aid clinicians with decisions regarding major therapeutic modalities.

scholarly journals DNA Repair: Exploiting the Fanconi Anemia Pathway As a Potential Therapeutic Target

2011 ◽  
pp. 453-465 ◽  
Author(s):  
T. HUCL ◽  
E. GALLMEIER
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Synthetic Lethality ◽  
Bone Marrow Failure ◽  
Long Term Effects ◽  
Alternative Pathways ◽  
Repair Mechanisms ◽  
Relationship Of

DNA repair is an active cellular process to respond to constant DNA damage caused by metabolic processes and environmental factors. Since the outcome of DNA damage is generally adverse and long term effects may contribute to oncogenesis, cells have developed a variety of DNA repair mechanisms, which operate depending on the type of DNA damage inflicted. At least 15 Fanconi anemia (FA) proteins interact in a common pathway involved in homologous recombination. Inherited homozygous mutations in any of these FA genes cause a rare disease, Fanconi anemia, characterized by congenital abnormalities, progressive bone-marrow failure and cancer susceptibility. Heterozygous germline FA mutations predispose to various types of cancer. In addition, somatic FA mutations have been identified in diverse cancer types. Evidence exists that cells deficient in the FA pathway become dependent on alternative pathways for survival. Additional inhibition of such alternative pathways is thus expected to result in cell death, creating a relationship of synthetic lethality. Identifying these relationships can reveal yet unknown mechanisms of DNA repair and new targets for therapy.

A Novel BTB/POZ Transcriptional Repressor Protein Interacts With the Fanconi Anemia Group C Protein and PLZF

Blood ◽  
1999 ◽  
Vol 94 (11) ◽  
pp. 3737-3747 ◽  
Author(s):  
Maureen E. Hoatlin ◽  
Yu Zhi ◽  
Helen Ball ◽  
Kirsten Silvey ◽  
Ari Melnick ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Transcriptional Repression ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Severe Disease ◽  
Transcriptional Repressor ◽  
Interaction Domain ◽  
C Protein ◽  
Amino Terminal ◽  
Anemia Group

Fanconi anemia (FA) is an autosomal recessive cancer susceptibility syndrome. The phenotype includes developmental defects, bone marrow failure, and cell cycle abnormalities. At least eight complementation groups (A-H) exist, and although three of the corresponding complementation group genes have been cloned, they lack recognizable motifs, and their functions are unknown. We have isolated a binding partner for the Fanconi anemia group C protein (FANCC) by yeast two-hybrid screening. We show that the novel gene, FAZF, encodes a 486 amino acid protein containing a conserved amino terminal BTB/POZ protein interaction domain and three C-terminal Krüppel-like zinc fingers. FAZF is homologous to the promyelocytic leukemia zinc finger (PLZF) protein, which has been shown to act as a transcriptional repressor by recruitment of nuclear corepressors (N-CoR, Sin3, and HDAC1 complex). Consistent with a role in FA, BTB/POZ-containing proteins have been implicated in oncogenesis, limb morphogenesis, hematopoiesis, and proliferation. We show that FAZF is a transcriptional repressor that is able to bind to the same DNA target sequences as PLZF. Our data suggest that the FAZF/FANCC interaction maps to a region of FANCC deleted in FA patients with a severe disease phenotype. We also show that FAZF and wild-type FANCC can colocalize in nuclear foci, whereas a patient-derived mutant FANCC that is compromised for nuclear localization cannot. These results suggest that the function of FANCC may be linked to a transcriptional repression pathway involved in chromatin remodeling.

scholarly journals The effect of the Fanconi anemia polypeptide, FAC, upon p53 induction and G2 checkpoint regulation

Blood ◽  
1996 ◽  
Vol 88 (3) ◽  
pp. 1019-1025 ◽  
Author(s):  
GM Kupfer ◽  
AD D'Andrea
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Cell Lines ◽  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Bone Marrow Failure ◽  
Alkylating Agents ◽  
P53 Pathway ◽  
G2 Checkpoint ◽  
G2 Phase

Fanconi anemia (FA) is an autosomal recessive disease marked by developmental defects, bone marrow failure, and cancer susceptibility. FA cells are hypersensitive to DNA cross-linking and alkylating agents and accumulate in the G2 phase of the cell cycle in response to these agents. FA cells also display genomic instability, suggesting a possible defect in the p53 pathway. To test the effect of heterologous expression of FAC cDNA on drug-induced cytotoxicity, G2 accumulation, and p53 induction in FA cells, we compared two isogenic FA cell lines: HSC536N (mock), a FA type C cell line sensitive to mitomycin C (MMC), and the same cell line transfected (corrected) with wild-type FAC cDNA (HSC536N [+FAC]). HSC536N (+FAC) cells showed a 30-fold increase in resistance to MMC concentration. Similarly, increases in resistance were observed following exposure to cisplatin, carboplatin, and cyclophosphamide. In addition, HSC536N (+FAC) cells showed a twofold lower G2 accumulation following MMC treatment. To analyze the possible interaction of FAC with the p53 pathway, we analyzed p53 induction in mock and corrected cell lines following exposure to MMC. HSC536N (mock) cells induced p53 at lower MMC concentrations than HSC536N (corrected). Caffeine, a known G2 checkpoint inhibitor, not only inhibited G2 accumulation seen in both cell lines but also caused the resistant HSC536N (+FAC) to become as sensitive to MMC as HSC536N (mock) cell line. We conclude that the FAC protein has a specific cytoprotective effect and may function as a cell cycle regulator of the G2 phase of the cell cycle.

scholarly journals Comprehensive analysis on phenotype and genetic basis of Chinese Fanconi anemia patients: dismal outcomes call for nationwide studies

2020 ◽  
Author(s):  
Daijing Nie ◽  
Jing Zhang ◽  
Fang Wang ◽  
Wei Zhang ◽  
Lili Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fanconi Anemia ◽  
Genetic Basis ◽  
Bone Marrow Failure ◽  
Severe Infection ◽  
Multicenter Studies ◽  
Hematopoietic Stem ◽  
Cytogenetic Abnormalities ◽  
Number Of Patients

Abstract Background: Fanconi anemia (FA) is the most common inherited bone marrow failure (BMF) syndrome with 22 related genes identified. The ALDH2 rs671variant has been proved related to accelerate the progression of BMF in FA patients. The phenotype and genetic basis of Chinese FA patients have not been investigated yet. Methods: We analyzed the 22 FA-related genes of 63 BMF patients suspected to be FA.Clinical manifestations, morphological and cytogenetic feathers, ALDH2 genotypes, treatment, and outcomes of the definite cases were retrospectively studied. Results: A total of 21 patients were confirmed the diagnosis of FA with the median age of BMF onset was 4-year-old. The number of patients manifested as congenital malformations and growth retardation were 20/21 and 14/21, respectively. BM dysplasia and cytogenetic abnormalities were found in 13/20 and 8/19 patients. All the patients with abnormal karyotypes also manifested as BM dysplasia or had evident blasts. Thirty-five different mutations were identified involving six genes and including twenty novel mutations. FANCA mutations contributed to 66.67% of cases. Eight patients harboring ALDH2 -G/A genotype have a significantly younger age of BMF onset ( p =0.025). Within the 19 patients adhering to continuous follow-up, 15 patients underwent hematopoietic stem cell transplantations (HSCTs). During the 29 months of follow-up, 8/19 patients died, seven of which were HSCT-related, and one patient who did not receive HSCT died from severe infection. Conclusion: The phenotypic and genetic spectrum of Chinese FA patients is broad. Bone marrow dysplasia and cytogenetic abnormalities are prevalent and highly consistent. The overall outcome of HSCTs is disappointing. Nationwide multicenter studies are needed for the rarity and adverse outcome of this disease.

scholarly journals Comprehensive analysis on phenotype and genetic basis of Chinese Fanconi anemia patients: dismal outcomes call for nationwide studies

2020 ◽  
Author(s):  
Daijing Nie ◽  
Jing Zhang ◽  
Fang Wang ◽  
Wei Zhang ◽  
Lili Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fanconi Anemia ◽  
Genetic Basis ◽  
Bone Marrow Failure ◽  
Severe Infection ◽  
Multicenter Studies ◽  
Hematopoietic Stem ◽  
Cytogenetic Abnormalities ◽  
Number Of Patients

Abstract Background: Fanconi anemia (FA) is the most common inherited bone marrow failure (BMF) syndrome with 22 related genes identified. The ALDH2 rs671variant has been proved related to accelerate the progression of BMF in FA patients. The phenotype and genetic basis of Chinese FA patients have not been investigated yet. Methods: We analyzed the 22 FA-related genes of 63 BMF patients suspected to be FA.Clinical manifestations, morphological and cytogenetic feathers, ALDH2 genotypes, treatment, and outcomes of the definite cases were retrospectively studied. Results: A total of 21 patients were confirmed the diagnosis of FA with the median age of BMF onset was 4-year-old. The number of patients manifested as congenital malformations and growth retardation were 20/21 and 14/21, respectively. BM dysplasia and cytogenetic abnormalities were found in 13/20 and 8/19 patients. All the patients with abnormal karyotypes also manifested as BM dysplasia or had evident blasts. Thirty-five different mutations were identified involving six genes and including twenty novel mutations. FANCA mutations contributed to 66.67% of cases. Eight patients harboring ALDH2 -G/A genotype have a significantly younger age of BMF onset ( p =0.025). Within the 19 patients adhering to continuous follow-up, 15 patients underwent hematopoietic stem cell transplantations (HSCTs). During the 29 months of follow-up, 8/19 patients died, seven of which were HSCT-related, and one patient who did not receive HSCT died from severe infection. Conclusion: The phenotypic and genetic spectrum of Chinese FA patients is broad. Bone marrow dysplasia and cytogenetic abnormalities are prevalent and highly consistent. The overall outcome of HSCTs is disappointing. Nationwide multicenter studies are needed for the rarity and adverse outcome of this disease.

scholarly journals On the role of FAN1 in Fanconi anemia

Blood ◽  
2012 ◽  
Vol 120 (1) ◽  
pp. 86-89 ◽  
Author(s):  
Juan P. Trujillo ◽  
Leonardo B. Mina ◽  
Roser Pujol ◽  
Massimo Bogliolo ◽  
Joris Andrieux ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Bone Marrow Failure ◽  
Pcr Amplification ◽  
Minor Role ◽  
Interstrand Crosslink ◽  
Genetic Features ◽  
Chromosome Fragility ◽  
A Minor ◽  
Interstrand Crosslink Repair ◽  
Crosslink Repair

Abstract Fanconi anemia (FA) is a rare bone marrow failure disorder with defective DNA interstrand crosslink repair. Still, there are FA patients without mutations in any of the 15 genes individually underlying the disease. A candidate protein for those patients, FA nuclease 1 (FAN1), whose gene is located at chromosome 15q13.3, is recruited to stalled replication forks by binding to monoubiquitinated FANCD2 and is required for interstrand crosslink repair, suggesting that mutation of FAN1 may cause FA. Here we studied clinical, cellular, and genetic features in 4 patients carrying a homozygous 15q13.3 micro-deletion, including FAN1 and 6 additional genes. Biallelic deletion of the entire FAN1 gene was confirmed by failure of 3′- and 5′-PCR amplification. Western blot analysis failed to show FAN1 protein in the patients' cell lines. Chromosome fragility was normal in all 4 FAN1-deficient patients, although their cells showed mild sensitivity to mitomycin C in terms of cell survival and G2 phase arrest, dissimilar in degree to FA cells. Clinically, there were no symptoms pointing the way to FA. Our results suggest that FAN1 has a minor role in interstrand crosslink repair compared with true FA genes and exclude FAN1 as a novel FA gene.

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