Fanconi Anaemia
CancerIndex Home - Children's Cancer Web Home > Cancer Types > Other & Related > Fanconi Anaemia

What is Fanconi Anaemia ?

Fanconi Anaemia is a rare disorder found in children that involves the blood and bone marrow. The symptoms include severe aplastic anemia, hypoplasia of the bone marrow, and patchy discoloration of the skin. This is an autosomal recessive condition, affected children usually develop severe aplastic anemia by age 8 to 9 years. Treatment usually consists of bone marrow transplant. Fanconi Anaemia is not a cancer, though recent research has shown an association between Fanconi Anaemia and leukaemia. There are 8 types of Fanconi Anaemia; known as complementation groups A through to H.

Some definitions:

Anemia
below normal levels of erythrocytes (red blood cells)
Aplastic anemia
anemia that is resistant to treatment; often accompanied by deficiencies of other blood cells.
Hypoplasia
incomplete / under development of a part of the body.
Pancytopenia
deficiency of all types of blood cells.
Recessive
(genetics) if the required allele (a type of gene) is not present in both members of a pair of chromosomes then that allele is not expressed.

Menu: Fanconi Anaemia

Information for Patients and Family
Information for Health Professionals / Researchers
Latest Research Publications
Aplastic Anaemia
Bone Marrow and Stem Cell Transplants
Childhood Leukaemia

Information Patients and Family (12 links)


Information for Health Professionals / Researchers (6 links)

See also: Molecular Biology of Fanconi Anaemia

Latest Research Publications

This list of publications is regularly updated (Source: PubMed).

Yao CJ, Du W, Zhang Q, et al.
Fanconi anemia pathway--the way of DNA interstrand cross-link repair.
Pharmazie. 2013; 68(1):5-11 [PubMed]
The study of rare genetic diseases usually inspires the research of cancer biology. Fanconi anemia (FA), is a rare cancer susceptibility syndrome with an incidence of only 1 per 350,000 births. FA is an autosomal recessive disease with three main features: chromosome instability, hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), cisplatin and so on, and susceptible to a number of cancer types, mainly leukemia and squamous cell carcinomas of the head and neck or gynecologic system. DNA crosslinking agents may led to DNA cross-linking lesion, and Fanconi anemia pathway plays a key role in repairing its cross-linking. However, FA pathway is closely linked with carcinogenesis and tumor drug resistance. This paper mainly focuses on the FA pathway and its progress in cancer research.


Shukla P, Rao A, Ghosh K, Vundinti BR
Identification of a novel large intragenic deletion in a family with Fanconi anemia: first molecular report from India and review of literature.
Gene. 2013; 518(2):470-5 [PubMed]
We report here an Indian case with Fanconi anemia (FA) presented with fever, pallor, short stature, hyperpigmentation and upper limb anomaly. Chromosome breakage analysis together with FANCD2 Western blot monoubiquitination assay confirmed the diagnosis as FA. Multiplex ligation-dependent probe amplification (MLPA) revealed a novel homozygous large intragenic deletion (exons 8-27 del) in the FANCA gene in the proband. His sib and parents were also analyzed and found to be heterozygous for the same mutation. We also reviewed the literature of FANCA large intragenic deletions found in FA patients from different countries and the mechanism involved in the formation of these deletions. To the best of our knowledge, this is the first molecular report from India on FA. The finding expands the mutation spectrum of the FANCA gene. Identification of the mutation confirms the diagnosis of FA at DNA level and helps in providing proper genetic counseling to the family.


Kottemann MC, Smogorzewska A
Fanconi anaemia and the repair of Watson and Crick DNA crosslinks.
Nature. 2013; 493(7432):356-63 [PubMed]
The function of Fanconi anaemia proteins is to maintain genomic stability. Their main role is in the repair of DNA interstrand crosslinks, which, by covalently binding the Watson and the Crick strands of DNA, impede replication and transcription. Inappropriate repair of interstrand crosslinks causes genomic instability, leading to cancer; conversely, the toxicity of crosslinking agents makes them a powerful chemotherapeutic. Fanconi anaemia proteins can promote stem-cell function, prevent tumorigenesis, stabilize replication forks and inhibit inaccurate repair. Recent advances have identified endogenous aldehydes as possible culprits of DNA damage that may induce the phenotypes seen in patients with Fanconi anaemia.


O'Driscoll M
Diseases associated with defective responses to DNA damage.
Cold Spring Harb Perspect Biol. 2012; 4(12) [PubMed]
Within the last decade, multiple novel congenital human disorders have been described with genetic defects in known and/or novel components of several well-known DNA repair and damage response pathways. Examples include disorders of impaired nucleotide excision repair, DNA double-strand and single-strand break repair, as well as compromised DNA damage-induced signal transduction including phosphorylation and ubiquitination. These conditions further reinforce the importance of multiple genome stability pathways for health and development in humans. Furthermore, these conditions inform our knowledge of the biology of the mechanics of genome stability and in some cases provide potential routes to help exploit these pathways therapeutically. Here, I will review a selection of these exciting findings from the perspective of the disorders themselves, describing how they were identified, how genotype informs phenotype, and how these defects contribute to our growing understanding of genome stability pathways.


Smith AR, Wagner JE
Current clinical management of Fanconi anemia.
Expert Rev Hematol. 2012; 5(5):513-22 [PubMed]
Fanconi anemia (FA) is a heterogeneous disease characterized by spontaneous chromosomal breaks and abnormal DNA repair. Major clinical problems in FA include congenital abnormalities, endocrinopathies, early onset bone marrow failure and increased risk of myelodysplastic syndrome, acute leukemia and solid tumors. To date, 15 different genes have been shown to cause FA, all of which have some role in DNA double-strand break repair. Very few strict genotype-phenotype associations have been identified and clinical manifestations vary widely from patient to patient, most likely due to modifier genes, environment and chance effects. Hematopoietic stem cell transplantation is the only proven cure for the hematopoietic manifestations of FA and aggressive lifelong surveillance for solid tumors is essential.


Kee Y, D'Andrea AD
Molecular pathogenesis and clinical management of Fanconi anemia.
J Clin Invest. 2012; 122(11):3799-806 [PubMed] Free Access to Full Article
Fanconi anemia (FA) is a rare genetic disorder associated with a high frequency of hematological abnormalities and congenital anomalies. Based on multilateral efforts from basic scientists and clinicians, significant advances in our knowledge of FA have been made in recent years. Here we review the clinical features, the diagnostic criteria, and the current and future therapies of FA and describe the current understanding of the molecular basis of the disease.


Kim Y, Spitz GS, Veturi U, et al.
Regulation of multiple DNA repair pathways by the Fanconi anemia protein SLX4.
Blood. 2013; 121(1):54-63 [PubMed] Article available free on PMC after 03/01/2014
SLX4, the newly identified Fanconi anemia protein, FANCP, is implicated in repairing DNA damage induced by DNA interstrand cross-linking (ICL) agents, topoisomerase I (TOP1) inhibitors, and in Holliday junction resolution. It interacts with and enhances the activity of XPF-ERCC1, MUS81-EME1, and SLX1 nucleases, but the requirement for the specific nucleases in SLX4 function is unclear. Here, by complementing a null FA-P Fanconi anemia cell line with SLX4 mutants that specifically lack the interaction with each of the nucleases, we show that the SLX4-dependent XPF-ERCC1 activity is essential for ICL repair but is dispensable for repairing TOP1 inhibitor-induced DNA lesions. Conversely, MUS81-SLX4 interaction is critical for resistance to TOP1 inhibitors but is less important for ICL repair. Mutation of SLX4 that abrogates interaction with SLX1 results in partial resistance to both cross-linking agents and TOP1 inhibitors. These results demonstrate that SLX4 modulates multiple DNA repair pathways by regulating appropriate nucleases.


Lee HJ, Park S, Kang HJ, et al.
A case report of Fanconi anemia diagnosed by genetic testing followed by prenatal diagnosis.
Ann Lab Med. 2012; 32(5):380-4 [PubMed] Article available free on PMC after 03/01/2014
Fanconi anemia (FA) is a rare genetic disorder affecting multiple body systems. Genetic testing, including prenatal testing, is a prerequisite for the diagnosis of many clinical conditions. However, genetic testing is complicated for FA because there are often many genes that are associated with its development, and large deletions, duplications, or sequence variations are frequently found in some of these genes. This study describes successful genetic testing for molecular diagnosis, and subsequent prenatal diagnosis, of FA in a patient and his family in Korea. We analyzed all exons and flanking regions of the FANCA, FANCC, and FANCG genes for mutation identification and subsequent prenatal diagnosis. Multiplex ligation-dependent probe amplification analysis was performed to detect large deletions or duplications in the FANCA gene. Molecular analysis revealed two mutations in the FANCA gene: a frameshift mutation c.2546delC and a novel splice-site mutation c.3627-1G>A. The FANCA mutations were separately inherited from each parent, c.2546delC was derived from the father, whereas c.3627-1G>A originated from the mother. The amniotic fluid cells were c.3627-1G>A heterozygotes, suggesting that the fetus was unaffected. This is the first report of genetic testing that was successfully applied to molecular diagnosis of a patient and subsequent prenatal diagnosis of FA in a family in Korea.


Yuan C, Xu N, Liao J
Switch of FANCL, a key FA-BRCA component, between tumor suppressor and promoter by alternative splicing.
Cell Cycle. 2012; 11(18):3356 [PubMed] Article available free on PMC after 03/01/2014
Comment on: Panneerselvam J, et al. Cell Cycle 2012; 11:2947-55.


Salewsky B, Schmiester M, Schindler D, et al.
The nuclease hSNM1B/Apollo is linked to the Fanconi anemia pathway via its interaction with FANCP/SLX4.
Hum Mol Genet. 2012; 21(22):4948-56 [PubMed]
The recessive genetic disorder Fanconi anemia (FA) is clinically characterized by congenital defects, bone marrow failure and an increased incidence of cancer. Cells derived from FA patients exhibit hypersensitivity to DNA interstrand crosslink (ICL)-inducing agents. We have earlier reported a similar cellular phenotype for human cells depleted of hSNM1B/Apollo (siRNA). In fact, hSNM1B/Apollo has a dual role in the DNA damage response and in generation and maintenance of telomeres, the latter function involving interaction with the shelterin protein TRF2. Here we find that ectopically expressed hSNM1B/Apollo co-immunoprecipitates with SLX4, a protein recently identified as a new FA protein, FANCP, and known to interact with several structure-specific nucleases. As shown by immunofluorescence analysis, FANCP/SLX4 depletion (siRNA) resulted in a significant reduction of hSNM1B/Apollo nuclear foci, supporting the functional relevance of this new protein interaction. Interestingly, as an additional consequence of FANCP/SLX4 depletion, we found a reduction of cellular TRF2, in line with its telomere-related function. Finally, analysis of human cells following double knockdown of hSNM1B/Apollo and FANCP/SLX4 indicated that they function epistatically. These findings further substantiate the role of hSNM1B/Apollo in a downstream step of the FA pathway during the repair of DNA ICLs.


McHugh PJ, Ward TA, Chovanec M
A prototypical Fanconi anemia pathway in lower eukaryotes?
Cell Cycle. 2012; 11(20):3739-44 [PubMed] Article available free on PMC after 15/10/2013
DNA interstrand cross-links (ICLs) present a major challenge to cells, preventing separation of the two strands of duplex DNA and blocking major chromosome transactions, including transcription and replication. Due to the complexity of removing this form of DNA damage, no single DNA repair pathway has been shown to be capable of eradicating ICLs. In eukaryotes, ICL repair is a complex process, principally because several repair pathways compete for ICL repair intermediates in a strictly cell cycle-dependent manner. Yeast cells require a combination of nucleotide excision repair, homologous recombination repair and postreplication repair/translesion DNA synthesis to remove ICLs. There are also a number of additional ICL repair factors originally identified in the budding yeast Saccharomyces cerevisiae, called Pso1 though 10, of which Pso2 has an apparently dedicated role in ICL repair. Mammalian cells respond to ICLs by a complex network guided by factors mutated in the inherited cancer-prone disorder Fanconi anemia (FA). Although enormous progress has been made over recent years in identifying and characterizing FA factors as well as in elucidating certain aspects of the biology of FA, the mechanistic details of the ICL repair defects in FA patients remain unknown. Dissection of the FA DNA damage response pathway has, in part, been limited by the absence of FA-like pathways in highly tractable model organisms, such as yeast. Although S. cerevisiae possesses putative homologs of the FA factors FANCM, FANCJ and FANCP (Mph1, Chl1 and Slx4, respectively) as well as of the FANCM-associated proteins MHF1 and MHF2 (Mhf1 and Mhf2), the corresponding mutants display no significant increase in sensitivity to ICLs. Nevertheless, we and others have recently shown that these FA homologs, along with several other factors, control an ICL repair pathway, which has an overlapping or redundant role with a Pso2-controlled pathway. This pathway acts in S-phase and serves to prevent ICL-stalled replication forks from collapsing into DNA double-strand breaks.


Prieto-Remón I, Sánchez-Carrera D, López-Duarte M, et al.
BIK (NBK) is a mediator of the sensitivity of Fanconi anaemia group C lymphoblastoid cell lines to interstrand DNA cross-linking agents.
Biochem J. 2012; 448(1):153-63 [PubMed]
FA (Fanconi anaemia) is a rare hereditary disorder characterized by congenital malformations, progressive bone marrow failure and an extraordinary predisposition to develop cancer. At present, 15 genes have been related to this condition and mutations of them have also been found in different types of cancer. Bone marrow failure threatens the life of FA patients during the first decade of their life, but the mechanisms underlying this process are not completely understood. In the present study we investigate a possible imbalance between the expression of pro- and anti-apoptotic proteins as a cause for the hypersensitivity of FANCC (FA, complementation group C)-deficient cells to genotoxic stress. We found a BIK (Bcl-2 interacting killer) over-expression in lymphoblastoid cell lines derived from FA-C patients when compared with their phenotypically corrected counterparts. This overexpression has a transcriptional basis since the regulatory region of the gene shows higher activity in FANCC-deficient cells. We demonstrate the involvement of BIK in the sensitivity of FA-C lymphoblasts to interstrand DNA cross-linking agents as it is induced by these drugs and interference of its expression in these cells preserves their viability and reduces apoptosis. We investigate the mechanism of BIK overexpression in FANCC-deficient cells by analysing the activity of many different signalling pathways in these cells. Finally, we provide evidence of a previously undescribed indirect epigenetic regulation of BIK in FA-C lymphoblasts mediated by ΔNp73, an isoform of p73 lacking its transactivation domain that activates BIK through a proximal element in its promoter.


Thakar MS, Bonfim C, Sandmaier BM, et al.
Cyclophosphamide-based in vivo T-cell depletion for HLA-haploidentical transplantation in Fanconi anemia.
Pediatr Hematol Oncol. 2012; 29(6):568-78 [PubMed] Article available free on PMC after 01/09/2013
Allogeneic hematopoietic cell transplantation (HCT) is the only known cure for patients with Fanconi anemia (FA) who develop aplasia or leukemia. However, transplant regimens typically contain high-dose alkylators, which are poorly tolerated in FA patients. Furthermore, as many patients lack human leukocyte antigen (HLA)-matched family donors, alternative donors are used, which can increase the risk of both graft rejection and graft-versus-host disease (GVHD). To improve on these three concerns, we developed a multi-institutional clinical trial using a fludarabine (FLU)-based conditioning regimen with limited alkylators/low-dose radiation, HLA-haploidentical marrow, followed by reduced-dose cyclophosphamide (CY) to treat three FA patients with aplasia. All three patients engrafted with 100% donor CD3 chimerism at 1 month. One patient died early from disseminated toxoplasmosis infection. Of the two survivors, one had significant pretransplant co-morbidities and inadequate immunosuppression, and developed severe acute GVHD. The other patient had only mild acute and no chronic GVHD. With a follow-up of 2 and 3 years, respectively, both patients are doing well, are transfusion-independent, and maintain full donor chimerism. The patient with severe GVHD has resolving oral GVHD and good quality of life. We conclude that using low-intensity conditioning, HLA-haploidentical marrow, and reduced-dose CY for in vivo T-cell depletion can correct life-threatening aplasia in FA patients.


Panneerselvam J, Park HK, Zhang J, et al.
FAVL impairment of the Fanconi anemia pathway promotes the development of human bladder cancer.
Cell Cycle. 2012; 11(15):2947-55 [PubMed] Article available free on PMC after 01/09/2013
Effectiveness of DNA cross-linking drugs in the treatment of bladder cancer suggests that bladder cancer cells may have harbored an insufficient cellular response to DNA cross-link damage, which will sensitize cells to DNA cross-linking agents. Cell sensitivity benefits from deficient DNA damage responses, which, on the other hand, can cause cancer. Many changed cellular signaling pathways are known to be involved in bladder tumorigenesis; however, DNA cross-link damage response pathway [Fanconi anemia (FA) pathway], whose alterations appear to be a plausible cause of the development of bladder cancer, remains an under-investigated area in bladder cancer research. In this study, we found FAVL (variant of FA protein L--FANCL) was elevated substantially in bladder cancer tissues examined. Ectopic expression of FAVL in bladder cancer cells as well as normal human cells confer an impaired FA pathway and hypersensitivity to Mitomycin C, similar to those found in FA cells, indicating that FAVL elevation may possess the same tumor promotion potential as an impaired FA pathway harbored in FA cells. Indeed, a higher level of FAVL expression can promote the growth of bladder cancer cells in vitro and in vivo, which, at least partly, results from FAVL perturbation of FANCL expression, an essential factor for the activation of the FA pathway. Moreover, a higher level of FAVL expression was found to be associated with chromosomal instability and the invasiveness of bladder cancer cells. Collectively, FAVL elevation can increase the tumorigenic potential of bladder cancer cells, including the invasive potential that confers the development of advanced bladder cancer. These results enhance our understanding the pathogenesis of human bladder cancer, holding a promise to develop additional effective tools to fight human bladder cancer.


Müller LU, Schlaeger TM, DeVine AL, Williams DA
Induced pluripotent stem cells as a tool for gaining new insights into Fanconi anemia.
Cell Cycle. 2012; 11(16):2985-90 [PubMed] Article available free on PMC after 15/08/2013
Induced pluripotent stem cells (iPSC) hold significant promise for advancing biomedical research. In the case of monogenic diseases, patient-iPSC and their derivatives contain the disease-causing mutation, suggesting the possibility of recapitulating salient disease features in vitro. Fanconi anemia (FA) is the most common inherited bone marrow failure syndrome. The etiology of bone marrow failure in FA remains largely unclear, but limited studies on patient bone marrow cells indicate cell intrinsic defects as causative. We examined the feasibility of modeling FA in a system based on hematopoietic differentiation of patient-specific iPSC. An informative iPSC-based model is predicated on the ability to derive disease-specific (uncorrected) patient iPSC that contain the disease-causing mutation, are pluripotent, maintain a normal karyotype and are capable of hematopoietic differentiation. Careful analysis of hematopoietic differentiation of such iPSC holds the promise of uncovering new insights into bone marrow failure and may enable high-throughput screening with the goal of identifying compounds that ameliorate hematopoietic failure. Ultimately, genetic correction, molecular characterization and successful engraftment of iPSC-derived cells may provide an attractive alternative to current hematopoietic stem cell-targeted gene therapy in some monogenic diseases, including FA.


Schlacher K, Wu H, Jasin M
A distinct replication fork protection pathway connects Fanconi anemia tumor suppressors to RAD51-BRCA1/2.
Cancer Cell. 2012; 22(1):106-16 [PubMed]
Genes mutated in patients with Fanconi anemia (FA) interact with the DNA repair genes BRCA1 and BRCA2/FANCD1 to suppress tumorigenesis, but the molecular functions ascribed to them cannot fully explain all of their cellular roles. Here, we show a repair-independent requirement for FA genes, including FANCD2, and BRCA1 in protecting stalled replication forks from degradation. Fork protection is surprisingly rescued in FANCD2-deficient cells by elevated RAD51 levels or stabilized RAD51 filaments. Moreover, FANCD2-mediated fork protection is epistatic with RAD51 functions, revealing an unanticipated fork protection pathway that connects FA genes to RAD51 and the BRCA1/2 breast cancer suppressors. Collective results imply a unified molecular mechanism for repair-independent functions of FA, RAD51, and BRCA1/2 proteins in preventing genomic instability and suppressing tumorigenesis.


Dumitriu B, Young NS
Damage control and its costs: BM failure in Fanconi anemia stems from overactive p53/p21.
Cell Stem Cell. 2012; 11(1):7-8 [PubMed] Article available free on PMC after 06/07/2013
Despite having well-characterized disease-associated mutations, the mechanisms underlying the progressive bone marrow failure and cancer susceptibility of Fanconi anemia have been unclear. In this issue of Cell Stem Cell, Ceccaldi et al. identify an overactive p53/p21 stress response and cell cycle arrest as an underlying cause that starts during fetal development.


Kim H, D'Andrea AD
Regulation of DNA cross-link repair by the Fanconi anemia/BRCA pathway.
Genes Dev. 2012; 26(13):1393-408 [PubMed] Article available free on PMC after 06/07/2013
The maintenance of genome stability is critical for survival, and its failure is often associated with tumorigenesis. The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand cross-links (ICLs), and a germline defect in the pathway results in FA, a cancer predisposition syndrome driven by genome instability. Central to this pathway is the monoubiquitination of FANCD2, which coordinates multiple DNA repair activities required for the resolution of ICLs. Recent studies have demonstrated how the FA pathway coordinates three critical DNA repair processes, including nucleolytic incision, translesion DNA synthesis (TLS), and homologous recombination (HR). Here, we review recent advances in our understanding of the downstream ICL repair steps initiated by ubiquitin-mediated FA pathway activation.


Mushtaq N, Wali R, Fadoo Z, Saleem AF
Acute lymphoblastic leukemia in a child with Fanconi's anaemia.
J Coll Physicians Surg Pak. 2012; 22(7):458-60 [PubMed]
Fanconi anaemia (FA) is an autosomal recessive inherited disorder with progressive bone marrow failure, associated congenital malformation and solid and haematological malignancies. Acute myeloid leukemia is the commonest haematological malignancy followed by myelodysplastic syndrome in children with FA. FA transformed into acute lymphoblastic leukemia (ALL) is a rare phenomenon and one of the rarest haematological malignancies associated with this disorder. We are reporting a 13 years old girl with FA and positive chromosomal breakage. She required regular blood product transfusion. She was planned for haematopoietic stem cell transplantation (HSCT) but the sibling-matched donor was found to have chromosomal breaks as well. Later on, her peripheral smear showed blast cell. Bone marrow showed pre-B ALL. She was started on chemotherapy but died shortly due to complications of the treatment. For this rare condition conservative management is indeed essential, however, safe and appropriate chemotherapy regimen is needed.


Stecklein SR, Jensen RA
Identifying and exploiting defects in the Fanconi anemia/BRCA pathway in oncology.
Transl Res. 2012; 160(3):178-97 [PubMed]
Defects in components of DNA repair pathways are responsible for numerous hereditary cancer syndromes and are also common in many sporadic malignancies. Inherited mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 or components of the Fanconi anemia (FA) complex incite genomic instability and predispose to malignancy. The products of the BRCA and FA genes participate in a conserved DNA damage repair pathway that is responsible for repairing interstrand crosslinks and double-strand DNA breaks by homologous recombination. While the genetic instability resulting from FA/BRCA dysfunction contributes to cancer pathogenesis, deficiency of these genes also lends to therapeutic exploitation. Crosslinking agents and ionizing radiation induce damage in cancer cells that requires the FA/BRCA pathway to be resolved; thus cancers that are deficient in BRCA1, BRCA2, or any other component of the FA/BRCA pathway are hypersensitive to these agents. Moreover, emerging synthetic lethal strategies offer opportunities to selectively target cancer cells with defects in homologous recombination. Conversely, enhanced activity of the FA/BRCA pathway is responsible for acquired resistance to specific therapeutic agents, suggesting that both dysfunction and hyperfunction of the FA/BRCA repair machinery are rational targets for cancer therapy. Selection of specific cytotoxic agents based on repair capacity may improve responses and enable personalized cytotoxic chemotherapy. This article reviews the FA/BRCA pathway and current approaches to identify deficiencies within it, discusses synthetic lethality and enhanced repair capacity as causes of therapeutic hypersensitivity and resistance, respectively, and highlights recent studies that have linked FA/BRCA pathway function with therapeutic efficacy.


Ceccaldi R, Parmar K, Mouly E, et al.
Bone marrow failure in Fanconi anemia is triggered by an exacerbated p53/p21 DNA damage response that impairs hematopoietic stem and progenitor cells.
Cell Stem Cell. 2012; 11(1):36-49 [PubMed] Article available free on PMC after 06/07/2013
Fanconi anemia (FA) is an inherited DNA repair deficiency syndrome. FA patients undergo progressive bone marrow failure (BMF) during childhood, which frequently requires allogeneic hematopoietic stem cell transplantation. The pathogenesis of this BMF has been elusive to date. Here we found that FA patients exhibit a profound defect in hematopoietic stem and progenitor cells (HSPCs) that is present before the onset of clinical BMF. In response to replicative stress and unresolved DNA damage, p53 is hyperactivated in FA cells and triggers a late p21(Cdkn1a)-dependent G0/G1 cell-cycle arrest. Knockdown of p53 rescued the HSPC defects observed in several in vitro and in vivo models, including human FA or FA-like cells. Taken together, our results identify an exacerbated p53/p21 "physiological" response to cellular stress and DNA damage accumulation as a central mechanism for progressive HSPC elimination in FA patients, and have implications for clinical care.


Adair JE, Zhao X, Chien S, et al.
Cyclophosphamide promotes engraftment of gene-modified cells in a mouse model of Fanconi anemia without causing cytogenetic abnormalities.
J Mol Med (Berl). 2012; 90(11):1283-94 [PubMed] Article available free on PMC after 01/11/2013
A major hurdle for hematopoietic stem cell (HSC) gene therapy for inherited bone marrow disorders, including Fanconi anemia (FA), is adequate engraftment of gene-modified cells. A phenotypic defect in DNA repair renders FA patients sensitive to alkylating agents such as cyclophosphamide (Cy); however, at lower doses, Cy is well tolerated in the FA transplant setting. We tested whether non-alkylating agents could replace Cy for pretransplant conditioning to enhance engraftment of FANCA gene-modified hematopoietic cells. We compared Cy preconditioning with fludarabine (Flu) or cytarabine (AraC) or no conditioning as a control in fanca ( -/- ) mutant mice receiving gene-modified bone marrow cells. Only mice conditioned with Cy exhibited appreciable engraftment of gene-modified cells by PCR and resistance to mitomycin C (MMC). Cy administration following transplantation increased gene marking levels in all animals treated, but highest gene marking and corresponding MMC resistance were observed in mice receiving Cy pre- and posttransplantation. Importantly, no cytogenetic abnormalities were observed in Cy-treated mice. We conclude that Cy is an effective and superior preparative regimen with respect to engraftment of lentivirus-transduced cells and functional correction in fanca ( -/- ) mice. Thus, appropriately dosed Cy may provide a suitable conditioning regimen for FA patients undergoing HSC gene therapy.


Pagano G, Talamanca AA, Castello G, et al.
Oxidative stress in Fanconi anaemia: from cells and molecules towards prospects in clinical management.
Biol Chem. 2012; 393(1-2):11-21 [PubMed]
Fanconi anaemia (FA) is a genetic disease featuring bone marrow failure, proneness to malignancies, and chromosomal instability. A line of studies has related FA to oxidative stress (OS). This review attempts to evaluate the evidence for FA-associated redox abnormalities in the literature from 1981 to 2010. Among 2170 journal articles on FA evaluated, 162 related FA with OS. Early studies reported excess oxygen toxicity in FA cells that accumulated oxidative DNA damage. Prooxidant states were found in white blood cells and body fluids from FA patients as excess luminol-dependent chemiluminescence, 8-hydroxy-deoxyguanosine, reduced glutathione/oxidized glutathione imbalance, and tumour necrosis factor-α. Some FA gene products involved in redox homeostasis can be summarized as follows: (a) FANCA, FANCC, and FANCG interact with cytochrome P450-related activities and/or respond to oxidative damage; (b) FANCD2 in OS response interacts with forkhead box O3 and ataxia telangiectasia mutated protein; (c) FANCG is found in mitochondria and interacts with PRDX3, and FA-G cells display distorted mitochondria and decreased peroxidase activity; (d) FANCJ (BACH1/BRIP1) is a repressor of haeme oxygenase-1 gene and senses oxidative base damage; (e) antioxidants, such as tempol and resveratrol decrease cancer incidence and haematopoietic defects in Fancd2(-/-) mice. The overall evidence for FA-associated OS may suggest designing chemoprevention studies aimed at delaying the onset of OS-related clinical complications.


Ehlert K, Groll AH, Rossig C, et al.
Late graft failure in FA--case report and review of the literature.
Pediatr Transplant. 2012; 16(8):E360-3 [PubMed]
Hematological disorders in patients with FA can only be cured by allogeneic HSCT. Severe infections in primary and early secondary graft failures pose a particular risk. Whereas most graft failures occur within 100 days, those observed after day +100 are infrequent. Here, we present our analysis of a secondary graft failure more than five yr after a first allogeneic HSCT. In this patient, isolated thrombocytopenia over a period of 12 months resulted in a chimerism subset analysis revealing a considerable decrease in the CD34-positive donor cell fraction. After a second fludarabine-based preparative regimen, the patient received PBSC from the same donor. Chimerism returned to full donor in all subsets. This clinical course demonstrates that isolated thrombocytopenia can precede complete graft failure for several months. Our review of the literature on late graft failures in patients with FA after day +100 reveals the absence of fludarabine in the preparative regimen as a potential risk factor. Further clinical research is necessary to identify more suitable approaches for ensuring safe and stable engraftment.


Trujillo JP, Mina LB, Pujol R, et al.
On the role of FAN1 in Fanconi anemia.
Blood. 2012; 120(1):86-9 [PubMed]
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 G(2) 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.


Ponte F, Sousa R, Fernandes AP, et al.
Improvement of genetic stability in lymphocytes from Fanconi anemia patients through the combined effect of α-lipoic acid and N-acetylcysteine.
Orphanet J Rare Dis. 2012; 7:28 [PubMed] Article available free on PMC after 01/11/2013
Fanconi Anemia (FA) is a rare genetic disorder, characterized by progressive bone marrow failure and increased predisposition to cancer. Despite being highly heterogeneous, all FA patients are hypersensitive to alkylating agents, in particular to 1,2:3,4-diepoxybutane (DEB), and to oxidative damage. Recent studies point to defective mitochondria in FA cells, which is closely related with increased production of reactive oxygen species (ROS) and concomitant depletion of antioxidant defenses, of which glutathione is a well-known biomarker.The objective of the present work is to evaluate the putative protective effect of α-lipoic acid (α-LA), a mitochondrial protective agent, and N-acetylcysteine (NAC), a direct antioxidant and a known precursor for glutathione synthesis, in spontaneous and DEB-induced chromosome instability (CI) in lymphocyte cultures from FA patients.For that purpose, lymphocyte cultures from 15 FA patients and 24 healthy controls were pre-treated with 20 μM α-LA, 500 μM NAC and α-LA plus NAC at the same concentrations, and some of them were exposed to DEB (0.05 μg/ml). A hundred metaphases per treatment were scored to estimate the relative frequency of spontaneous and DEB-induced chromosome breakage.The obtained results revealed that a cocktail of α-LA and NAC can drastically improve the genetic stability in FA lymphocytes in vitro, decreasing CI by 60% and 80% in cultures from FA patients and FA mosaic/chimera patients, respectively. These results suggest that the studied cocktail can be used as a prophylactic approach to delay progressive clinical symptoms in FA patients caused by CI, which can culminate in the delay of the progressive bone marrow failure and early cancer development.


Knoll A, Higgins JD, Seeliger K, et al.
The Fanconi anemia ortholog FANCM ensures ordered homologous recombination in both somatic and meiotic cells in Arabidopsis.
Plant Cell. 2012; 24(4):1448-64 [PubMed] Article available free on PMC after 01/11/2013
The human hereditary disease Fanconi anemia leads to severe symptoms, including developmental defects and breakdown of the hematopoietic system. It is caused by single mutations in the FANC genes, one of which encodes the DNA translocase FANCM (for Fanconi anemia complementation group M), which is required for the repair of DNA interstrand cross-links to ensure replication progression. We identified a homolog of FANCM in Arabidopsis thaliana that is not directly involved in the repair of DNA lesions but suppresses spontaneous somatic homologous recombination via a RecQ helicase (At-RECQ4A)-independent pathway. In addition, it is required for double-strand break-induced homologous recombination. The fertility of At-fancm mutant plants is compromised. Evidence suggests that during meiosis At-FANCM acts as antirecombinase to suppress ectopic recombination-dependent chromosome interactions, but this activity is antagonized by the ZMM pathway to enable the formation of interference-sensitive crossovers and chromosome synapsis. Surprisingly, mutation of At-FANCM overcomes the sterility phenotype of an At-MutS homolog4 mutant by apparently rescuing a proportion of crossover-designated recombination intermediates via a route that is likely At-MMS and UV sensitive81 dependent. However, this is insufficient to ensure the formation of an obligate crossover. Thus, At-FANCM is not only a safeguard for genome stability in somatic cells but is an important factor in the control of meiotic crossover formation.


Shimada A, Takahashi Y, Muramatsu H, et al.
Excellent outcome of allogeneic bone marrow transplantation for Fanconi anemia using fludarabine-based reduced-intensity conditioning regimen.
Int J Hematol. 2012; 95(6):675-9 [PubMed]
Fanconi anemia (FA) is a disorder characterized by developmental anomalies, bone marrow failure and a predisposition to malignancy. It has recently been shown that hematopoietic stem cell transplantation using fludarabine (FLU)-based reduced-intensity conditioning is an efficient and quite safe therapeutic modality. We retrospectively analyzed the outcome of bone marrow transplantation (BMT) in eight patients with FA performed in two institutes between 2001 and 2011. There were seven females and one male with a median age at diagnosis = 4.5 years (range 2-12 years). The constitutional characteristics associated with FA, such as developmental anomalies, short stature and skin pigmentation, were absent in three of the patients. One patient showed myelodysplastic features at the time of BMT. All patients received BMT using FLU, cyclophosphamide (CY) and rabbit anti-thymocyte globulin (ATG) either from a related donor (n = 4) or an unrelated donor (n = 4). Acute graft-versus-host disease (GVHD) of grade I developed in one patient, while chronic GVHD was not observed in any patient. All patients are alive and achieved hematopoietic recovery at a median follow-up of 72 months (range 4-117 months). BMT using FLU/low-dose CY/ATG -based regimens regardless to the donor is a beneficial therapeutic approach for FA patients.


Rochowski A, Olson SB, Alonzo TA, et al.
Patients with Fanconi anemia and AML have different cytogenetic clones than de novo cases of AML.
Pediatr Blood Cancer. 2012; 59(5):922-4 [PubMed] Article available free on PMC after 01/11/2013
Specific cytogenetic clones might distinguish patients with unrecognized Fanconi anemia (FA) who present with acute myeloid leukemia (AML) from those with sporadic AML. Cytogenetic reports in literature cases of FA and AML were compared with de novo cases enrolled on CCG-2961. Gain of 1q, gain of 3q, monosomy 7, deleted 7q, gain of 13q, and deleted 20q were more frequent in FA AML; t(8;21), trisomy 8, t(9;11), t(6;9), and inversion 16 were exclusive to de novo AML cases. Observation of the FA AML cytogenetic clonal patterns should raise suspicion of an underlying leukemia predisposition syndrome and influence management.


Tunç B, Tavil B, Karakurt N, et al.
Deferasirox therapy in children with Fanconi aplastic anemia.
J Pediatr Hematol Oncol. 2012; 34(4):247-51 [PubMed]
Thirty-nine children with Fanconi aplastic anemia (FAA) have been followed up in our center between January 2008 and November 2010. Eight of these children (20%) with a transfusional iron overload had been undergoing deferasirox treatment during the study period. In the English literature, transfusional iron overload and the use of an iron chelator in children with FAA has not yet been evaluated. Here, we have presented the effectivity and tolerability of deferasirox in children with FAA and a transfusional iron overload. Before the deferasirox treatment, the mean serum ferritin level was 3377 ± 2200 ng/mL. After a mean 13.6-month treatment duration, the mean ferritin level decreased to 2274 ± 1300 ng/mL (P<0.05). In our series, 3 patients had renal and 3 had hepatic toxicity during the treatment. Two patients had peliosis hepatis and 2 had congenital renal abnormalities before the treatment. There may be differences in the side-effect profiles of deferasirox treatment in patients with FAA. In our series, despite the low number of cases, nephrotoxicity and hepatotoxicity were common side effects instead of gastrointestinal disturbances reported in other studies. Deferasirox is an oral, easily applicable, and effective iron chelator; baseline hepatotoxicity and nephrotoxicity may increase the development of toxic side effects in children with FAA. Patients with FAA receiving deferasirox treatment should be followed up closely for these side effects.


This page last updated: 22nd May 2013
Displaying links verified within last 2 weeks at time of update.

Children's Cancer Web Logo

Home
Site Map
Cancer Types
Treatments
Locations
Support & Information
Research
Health Professionals

About

Disclaimer
© 1996-2013