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

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 FANCC mutations (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.

Cancer incidence in persons with Fanconi anemia

Fanconi anemia (FA) is an autosomal recessive condition associated with congenital abnormalities, progressive pancytopenia, and a predisposition to leukemia and solid tumors. We studied a retrospective cohort of North American patients with FA. We calculated relative risks of cancer compared to the general population and cause-specific hazards of the first major adverse outcomes of FA: bone marrow transplantation (BMT) for marrow complications, acute myeloid leukemia (AML), solid tumors, or death from bone marrow failure. We also estimated the cumulative incidence of each adverse event in the presence of the competing risks. Among 145 patients with FA, 9 developed leukemia and 14 developed a total of 18 solid tumors. The ratio of observed to expected cancers (O/E ratio) was 50 for all cancers, 48 for all solid tumors, and 785 for leukemia; these increased risks were statistically significant. The highest solid tumor O/E ratios were 4317 for vulvar cancer, 2362 for esophageal cancer, and 706 for head and neck cancer. Cause-specific hazards of both death and AML peaked at 1%/y in teenage years; the hazard of BMT peaked at 4%/y at age 7. In contrast, the hazard of a solid tumor approached 8%/y by age 40 years. The cumulative incidence to age 48 was 10% for leukemia, 11% for death from marrow failure, 29% for a solid tumor, and 43% for BMT. The risk of a solid tumor may become even higher as death from aplastic anemia is reduced and as patients survive longer after BMT.

Cancer in Fanconi anemia, 1927-2001

BACKGROUND

Fanconi anemia (FA) is an autosomal recessive disease associated with an abnormal response to DNA damage. Although FA is well known for the association of aplastic anemia and characteristic birth defects, leukemia and solid tumors also occur at a high rate in this group of patients. A review of all reported cases is informative with regard to the specific types of cancer, the ages at which they occur, and the cumulative probability of their development.

METHODS

Medline and bibliographies of publications were searched for articles containing "Fanconi's anemia" or "aplastic anemia" and all cases of FA from 1927 through 2001 were included in the database. Cancer cases were identified within these reports. Descriptive statistical analyses were performed using Stata7 software.

RESULTS

One thousand three hundred cases of FA were identified. Nine percent had leukemia (primarily acute myeloid leukemia), 7% had myelodysplastic syndrome, 5% had solid tumors, and 3% had liver tumors. Patients with cancer were older than the cancer-free patients at the time of diagnosis of FA. The median age for cancer (including leukemia) was 16, compared with 68 in the general population. The most frequent solid tumors were aerodigestive and gynecological carcinomas. In approximately 25% of patients with cancer, the malignancy preceded the diagnosis of FA.

CONCLUSIONS

If the competing risks of aplastic anemia and leukemia could be removed, the estimated cumulative probability of development of a solid tumor in FA patients is 76% by the age of 45 years. Carcinogenic pathways and cancer prevention, surveillance, and treatment can be studied to advantage in this genetic model of human cancer.

Evidence for at least eight Fanconi anemia genes

Fanconi anemia (FA) is an autosomal recessive chromosomal breakage disorder with diverse clinical symptoms including progressive bone marrow failure and increased cancer risk. FA cells are hypersensitive to crosslinking agents, which has been exploited to assess genetic heterogeneity through complementation analysis. Five complementation groups (FA-A through FA-E) have so far been distinguished among the first 20 FA patients analyzed. Complementation groups in FA are likely to represent distinct disease genes, two of which (FAC and FAA) have been cloned. Following the identification of the first FA-E patient, additional patients were identified whose cell lines complemented groups A-D. To assess their possible assignment to the E group, we introduced selection markers into the original FA-E cell line and analyzed fusion hybrids with three cell lines classified as non-ABCD. All hybrids were complemented for cross-linker sensitivity, indicating nonidentity with group E. We then marked the three non-ABCDE cell lines and examined all possible hybrid combinations for complementation, which indicated that each individual cell line represented a separate complementation group. These results thus define three new groups, FA-F, FA-G, and FA-H, providing evidence for a minimum of eight distinct FA genes.

DNA repair pathways in clinical practice: lessons from pediatric cancer susceptibility syndromes

Human cancers exhibit genomic instability and an increased mutation rate due to underlying defects in DNA repair. Cancer cells are often defective in one of six major DNA repair pathways, namely: mismatch repair, base excision repair, nucleotide excision repair, homologous recombination, nonhomologous endjoining and translesion synthesis. The specific DNA repair pathway affected is predictive of the kinds of mutations, the tumor drug sensitivity, and the treatment outcome. The study of rare inherited DNA repair disorders, such as Fanconi anemia, has yielded new insights to drug sensitivity and treatment of sporadic cancers, such as breast or ovarian epithelial tumors, in the general population. The Fanconi anemia pathway is an example of how DNA repair pathways can be deregulated in cancer cells and how biomarkers of the integrity of these pathways could be useful as a guide to cancer management and may be used in the development of novel therapeutic agents.

Risk of head and neck squamous cell cancer and death in patients with Fanconi anemia who did and did not receive transplants

Hematopoietic stem cell transplant (SCT) is currently the only therapy that can restore normal hematopoiesis in patients with Fanconi anemia (FA). Patients with FA have a high baseline risk of squamous cell cancers (SCCs) of the head, neck, and esophagus, and SCT conditioning may increase SCC incidence. We evaluated the risks of SCC and death in 145 patients with FA in the North American Survey (NAS) cohort who did not receive transplants, and 117 patients with FA in the Hôpital Saint Louis (SLH) cohort who did receive transplants. The age-specific hazard of SCC was 4.4-fold higher in patients who received transplants than in those who did not (P = .003), and SCCs occurred at significantly younger ages in the former (respective medians, 18 and 33 years, P = .004). Survival after SCC was similarly poor in both cohorts (P = .135, median, 13 months). The hazard of SCC increased at a greater than linear rate, to 4.4% per year by age 40 in NAS and 4.7% per year by 10 years after transplant in SLH. In SLH, the hazard of non-SCC death was biphasic, declining significantly (P = .004) from 7.1% per month during the first 6 months after transplant to 0.13% per month (1.6% per year) after the first year. Acute and chronic graft-versus-host diseases were significant SCC risk factors. Adverse event rates in these cohorts provide historical control rates to assess emerging therapies for FA.

Malignancies and survival patterns in the National Cancer Institute inherited bone marrow failure syndromes cohort study

Fanconi anaemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anaemia (DBA), and Shwachman-Diamond syndrome (SDS) comprise major inherited bone marrow failure syndromes (IBMFS). Adverse events include severe bone marrow failure (BMF), myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML), and solid tumours (ST). The natural history of FA is well characterised; hazard rates in the other syndromes have not yet been quantified. An open cohort was established at the National Cancer Institute (NCI) in 2002. Patients enrolled prior to December, 2007 were followed up to December, 2008. Diagnoses were confirmed with standard tests. Age-associated risks of adverse events were calculated. Most patients in each syndrome survived to young adulthood. Patients with FA had earlier onset of cancers, need for stem cell transplant, and death; followed by DC; DBA and SDS were mildest. While FA and DC patients had markedly increased risks of cancer, AML and MDS, there were no cases of leukaemia in DBA or SDS patients. The NCI cohort provides the first direct quantitative comparison of timing and magnitude of cancer risk in the IBMFS. The findings demonstrate that both FA and DC are major cancer susceptibility syndromes. The IBMFS, historically considered paediatric disorders, have important management implications for physicians treating adult patients.

Fanconi's anemia and malignancies

Patients with Fanconi's anemia (FA) are at a high risk for development of malignancies. It is well-known that leukemia occurs in approximately 10% of cases, with increasing risk with age. Less commonly recognized is the risk for myelodysplastic syndromes (approximately 5%); the relationship between myelodysplasia and evolution to leukemia remains speculative. What also needs to be emphasized is that older patients have an ever-increasing risk for development of solid tumors, with at least 5% reported to have liver tumors (male:female ratio, 2:1) and an equal number of other cancers (female:male ratio, 3:1, even after exclusion of gynecologic malignancies). Hematologists have tended to focus on aplastic anemia and leukemia. As FA patients live longer, more of the other malignancies will occur, perhaps related to cord blood or bone marrow transplant, or treatment with cytokines. This review identifies the types of tumors for which patients with Fanconi's anemia are at risk.

Promoter hypermethylation of FANCF: disruption of Fanconi Anemia-BRCA pathway in cervical cancer

Patients with advanced stage invasive cervical cancer (CC) exhibit highly complex genomic alterations and respond poorly to conventional treatment protocols. In our efforts to understand the molecular genetic basis of CC, we examined the role of Fanconi Anemia (FA)-BRCA pathway. Here, we show that FANCF gene is disrupted by either promoter hypermethylation and/or deregulated gene expression in a majority of CC. Inhibition of DNA methylation and histone deacetylases induces FANCF gene re-expression in CC cell lines. FANCF-deregulated CC cell lines also exhibit a chromosomal hypersensitivity phenotype after exposure to an alkylating agent, a characteristic of FA patients. We also show the involvement of BRCA1 gene by promoter hypermethylation or down-regulated expression in a small subset of CC patients. Thus, we have found inactivation of genes in the FA-BRCA pathway by epigenetic alterations in a high proportion of CC patients, suggesting a major role for this pathway in the development of cervical cancer. Thus, these results have important implications in understanding the molecular basis of CC tumorigenesis and clinical management in designing targeted experimental therapeutic protocols.

Clinical radiation sensitivity with DNA repair disorders: an overview

Adverse reactions to radiotherapy represent a confounding phenomenon in radiation oncology. These reactions are rare, and many have been associated with individuals with DNA repair disorders such as ataxia-telangiectasia and Nijmegen Breakage syndrome. A paucity of published data is available detailing such circumstances. This overview describes four exemplary situations, a comprehensive list of 32 additional cases, and some insights gleaned from this overall experience. Fanconi anemia was associated with more than one-half of the reports. The lowest dose given to a patient that resulted in a reaction was 3 Gy, given to an ataxia-telangiectasia patient. Most patients died within months of exposure. It is clear that the patients discussed in this report had complicated illnesses, in addition to cancer, and the radiotherapy administered was most likely their best option. However, the underlying DNA repair defects make conventional radiation doses dangerous. Our findings support previous wisdom that radiotherapy should either be avoided or the doses should be selected with great care in the case of these radiosensitive genotypes, which must be recognized by their characteristic phenotypes, until more rapid, reliable, and functional assays of DNA repair become available.

Androgens and liver tumors: Fanconi's anemia and non-Fanconi's conditions

The association between anabolic androgenic steroids and liver tumors was first noted in patients with Fanconi's anemia (FA). The hypotheses which led to this review were as follows: (1) androgen-treated individuals who do not have FA are also at risk of liver tumors; (2) parenteral as well as oral androgens may be responsible for liver tumors; (3) FA patients develop liver tumors after smaller and briefer androgen exposure than non-FA individuals; (4) the risk of hepatic neoplasms may depend on the specific androgen. Medline and Web of Science were searched for all cases of liver tumors associated with androgens. Information from individual cases was entered into a spreadsheet and descriptive statistical analyses were performed. Thirty-six FA cases and 97 non-FA cases with both nonhematologic disorders and acquired aplastic anemia (non-FA AA) were identified. The most common androgens were oxymetholone, methyltestosterone, and danazol. Hepatocellular carcinomas (HCC) were more often associated with oxymetholone and methyltestosterone, while adenomas were associated with danazol. Tumors were reported in six patients who received only parenteral and not oral androgens. FA patients were younger than non-FA patients when androgen use was initiated, and the FA patients developed tumors at younger ages. Non-AA patients were treated with androgens for longer periods of time, compared with FA and non-FA AA patients. All patients on anabolic androgenic steroids are at risk of liver tumors, regardless of underlying diagnosis. The magnitude of the risk cannot be determined from currently available data, because the number of patients receiving androgens is unknown.

Human Papillomavirus DNA and p53 Polymorphisms in Squamous Cell Carcinomas From Fanconi Anemia Patients

Fanconi anemia is an autosomal recessive disorder characterized by congenital malformations, bone marrow failure, and the development of squamous cell carcinomas (SCCs) and other cancers. Recent clinicopathologic evidence has raised the possibility that an environmental factor such as human papillomavirus (HPV) may be involved in the pathogenesis of SCCs in Fanconi anemia patients. Given the high prevalence of p53 mutations in SCCs among the general population and the lack of p53 mutations in HPV-related carcinogenesis, we evaluated the role of HPV and p53 mutations and polymorphisms in SCC from Fanconi anemia patients. We used polymerase chain reaction (PCR) screening and real-time PCR to detect and quantify HPV DNA in DNA extracted from microdissected SCCs obtained from 24 Fanconi anemia patients (n = 25 SCCs; case subjects) and 50 age-, sex-, and tumor site-matched SCC patients without Fanconi anemia (n = 50 SCCs; control subjects). We PCR-amplified and sequenced exons 4-9 of the p53 gene from SCC DNA. We detected HPV DNA in 84% of the SCC specimens from the case subjects and in 36% of the SCC specimens from the control subjects (P<.001). The prevalence of p53 mutations in SCCs from the case subjects (0%, 0/25) was statistically significantly lower than that of SCCs from the control subjects (36%, 12/33; P<.001). A greater proportion of patients with Fanconi anemia and SCC were homozygous for Arg72, a p53 polymorphism that may be associated with increased risk for HPV-associated human malignancies, than an ethnically-matched cohort of Fanconi anemia patients without SCC (75% versus 51%; P =.05). These data suggest that Fanconi anemia is associated with increased susceptibility to HPV-induced carcinogenesis.

Surveillance for Wilms tumour in at-risk children: pragmatic recommendations for best practice

BACKGROUND

Most Wilms tumours occur in otherwise healthy children, but a small proportion occur in children with genetic syndromes associated with increased risks of Wilms tumour. Surveillance for Wilms tumour has become widespread, despite a lack of clarity about which children are at increased risk of these tumours and limited evidence of the efficacy of screening or guidance as to how screening should be implemented.

METHODS

The available literature was reviewed.

RESULTS

The potential risks and benefits of Wilms tumour surveillance are finely balanced and there is no clear evidence that screening reduces mortality or morbidity. Prospective evidence-based data on the efficacy of Wilms tumour screening would be difficult and costly to generate and are unlikely to become available in the foreseeable future.

CONCLUSIONS

The following pragmatic recommendations have been formulated for Wilms tumour surveillance in children at risk, based on our review: (1) Surveillance should be offered to children at >5% risk of Wilms tumour. (2) Surveillance should only be offered after review by a clinical geneticist. (3) Surveillance should be carried out by renal ultrasonography every 3-4 months. (4) Surveillance should continue until 5 years of age in all conditions except Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome and some familial Wilms tumour pedigrees where it should continue until 7 years. (5) Surveillance can be undertaken at a local centre, but should be carried out by someone with experience in paediatric ultrasonography. (6) Screen-detected lesions should be managed at a specialist centre.

Endocrine abnormalities in patients with Fanconi anemia

BACKGROUND

Fanconi anemia (FA) is an inherited disorder with chromosomal instability, bone marrow failure, developmental defects, and a predisposition to cancer. Systematic and comprehensive endocrine function data in FA are limited.

OBJECTIVE

We studied a cohort of FA patients enrolled in the National Cancer Institute's Inherited Bone Marrow Failure Syndrome study.

STUDY DESIGN AND PATIENTS

Retrospective review of the medical records of 45 FA patients (ages 2-49 yr), 23 of whom were intensively evaluated at the National Institutes of Health. Anthropometric measurements, GH, IGF-I, IGF binding protein-3, thyroid, gonadal hormone, lipid levels, glucose homeostasis, brain imaging, and bone mineral density were obtained in these latter patients.

RESULTS

Endocrine abnormalities were present in 73%, including short stature and/or GH deficiency (51%), hypothyroidism (37%), midline brain abnormalities (17%) (these patients had very short stature and 60% were GH-deficient); abnormal glucose/insulin metabolism (39%); obesity (27%); dyslipidemia (55%); and metabolic syndrome (21%). Patients with any endocrine abnormality were shorter than those without; only GH deficiency correlated significantly with short stature (P = 0.01). In addition, 65% of peripubertal or postpubertal patients had gonadal dysfunction. Ninety-two percent of the patients 18 yr or older had osteopenia or osteoporosis.

CONCLUSIONS

Endocrine dysfunction is widespread in children and adults with FA; we expand the FA phenotype to include early onset osteopenia/osteoporosis and lipid abnormalities. Despite the reputation of FA as a progressive, lethal disease, proper management of the full spectrum of FA-related endocrinopathy offers major opportunities to reduce morbidity and improve quality of life. Our findings emphasize the need for comprehensive endocrine and metabolic evaluation and long-term follow-up in patients with FA.

Fanconi anaemia and leukaemia - clinical and molecular aspects

Fanconi anaemia (FA) is an autosomal recessive chromosomal instability disorder, which is characterized by congenital abnormalities, defective haemopoiesis and a high risk of developing acute myeloid leukaemia and certain solid tumours. It can be caused by mutations in at least eight different genes. Molecular studies have established that a common pathway exists, both between the FA proteins and other proteins involved in DNA damage repair such as NBS1, ATM, BRCA1 and BRCA2. This review summarizes the general clinical and specific haematological features and the current management of FA. Recent molecular advances will also be discussed in the context of the cellular and clinical FA phenotype, with particular emphasis on the haematological aspects of the condition.

Oxidative stress in Fanconi anemia hematopoiesis and disease progression

Patients with the genomic instability syndrome Fanconi anemia (FA) commonly develop progressive bone marrow failure and have a high risk of cancer. The prominent role of the FA protein family involves DNA damage response and/or repair. Oxidative stress, defined as an imbalance between the production of reactive oxygen species and antioxidant defense, is considered to be an important pathogenic factor in leukemia-prone bone marrow diseases such as FA. Cellular responses inducing resistance to oxidative stress are important for cellular survival, organism lifespan, and cancer prevention, but until recently, mammalian factors regulating resistance to oxidative stress have not been well characterized. Significant evidence supports excessive apoptosis of hematopoietic stem/progenitor cells, induced by stresses, most significantly oxidative stress, as a critical factor in the pathogenesis of bone marrow failure and leukemia progression in FA. In this brief review, we discuss the functional link between FA proteins and oxidative DNA damage response/repair, with emphasis on the implication of oxidative stress in the pathophysiology and abnormal hematopoiesis in FA.

Osteogenic sarcoma associated with Diamond-Blackfan anemia: a report from the Diamond-Blackfan Anemia Registry

PURPOSE

Diamond-Blackfan anemia (DBA) is a congenital pure red cell aplasia, usually presenting in infancy or early childhood. A review of the literature strongly supports a predisposition to hematopoietic malignancy. Recently, solid tumors have been reported, some attributable to hemosiderosis and/or androgen therapy. Two cases of osteogenic sarcoma have also been documented. An analysis from the Diamond-Blackfan Anemia Registry was performed to evaluate the cancer risk in patients with DBA.

METHODS

The Diamond-Blackfan Anemia Registry of North America (DBAR) is a comprehensive database of patients with DBA enrolled, after informed consent, through outreach to pediatric hematologists and family groups. The patients and/or their families complete a detailed questionnaire, and a review of medical records and telephone interviews are performed to complete and clarify the information provided.

RESULTS

Of the 354 patients registered in the DBAR, there were six patients meeting the accepted diagnostic criteria for DBA who were found to have malignancies. Three patients had osteogenic sarcoma diagnosed, one with myelodysplastic syndrome, one with colon carcinoma, and one with a soft tissue sarcoma.

CONCLUSION

There appears to be an association of osteogenic sarcoma with DBA. A young age at presentation may be a feature of DBA-associated osteogenic sarcoma. Because of the immaturity of the database, the actuarial risk for osteogenic sarcoma and other cancers in individuals with DBA cannot be ascertained. Speculation is made regarding the nature of the molecular defect leading to the association of DBA and osteogenic sarcoma.

Diamond-Blackfan anemia. Natural history and sequelae of treatment

To define further the natural history of treated Diamond-Blackfan anemia (DBA), a congenital anemia characterized by a paucity of erythroid precursors, we analyzed 76 patients diagnosed or followed at Children's Hospital, Boston, between 1931 and 1992. Although DBA is generally defined as macrocytic, we found that mean corpuscular volume in infants aged <5 months rarely exceeded the normal range and is of little diagnostic value. Macrocytosis in patients aged > or = 5 months was more striking. Nine of 16 patients who never received steroids experienced remissions, sometimes after years of transfusions. Thirty-one of 56 patients receiving corticosteroids responded. Of these 31, 13 experienced remissions, 11 remained steroid dependent and 7 later required transfusions. Most nonresponders maintained transfusion dependence. Patients frequently (64%) experienced treatment-related morbidity, most commonly hemosiderosis. The relative risk of leukemia was profoundly elevated (RR, 200; 95% CI, 54.5-512.1) and hematologic parameters at long-term follow-up were often abnormal. While potential responsiveness to steroids and relative ease of red cell transfusion make DBA one of the most treatable congenital marrow failure syndromes, both disease-related and treatment-related factors contributed to a limited prognosis (median survival, 38 years). Patients should be carefully monitored longitudinally for evidence of leukemia and adverse effects of therapy, and alternative treatment strategies should be considered on an individual basis.

Radiosensitivity in Fanconi's anemia patients

The risks of radiation therapy in patients with Fanconi's anemia who have cancer are not clear. Possible toxicity was reported in six of 14 patients: 1/1 with vaginal cancer, 4/10 with head and neck or esophageal cancer, and 1/3 with oral cancer following bone marrow transplant.

Genetically determined chromosome instability syndromes

Spontaneously increased chromosomal instability is well documented in the three autosomal recessive diseases, Fanconi's anemia (FA), Bloom's syndrome (BS), and ataxia telangiectasia (AT). Other conditions have been reported to be associated with chromosomal breakage. Some are still single observations: in Werner's syndrome only fibroblasts are affected, and systemic sclerosis may not be an inherited disease. Various aspects of FA, BS, and AT are discussed which have emerged since recent reviews have been published. The differential diagnosis in FA has become more important than it was in the past. Proven heterogeneity in FA demands definition of what to name FA and FA variants. The analysis of cancer frequencies and types in FA and AT lacks important clues. This should stimulate all of us to mutual exchange of data and creation of registries not only of patients and follow-ups, but also of characterized cell strains. A synopsis of results from cell and cytogenetic studies demonstrates similarities and differences in detail of the general phenomenon of chromosomal instability which FA, BS, and AT share. Results from biochemical studies at the DNA level together with cytogenetic findings indicate different but still undefined failures in DNA metabolism or DNA repair mechanisms due to the different genes. A new approach to analyzing the impairment of DNA repair in FA is briefly described. DNA related enzymes are produced in the cytoplasm and have to be transported to the nucleus. The subcellular distribution of topoisomerase activity was found to be unusual in three placentas of FA patients. Other DNA enzymes were distributed normally. Thus, a specific mechanism for movement of the enzyme through the nuclear membrane seems to be defective.

Fanconi Anemia Signaling and Cancer

The extremely high cancer incidence associated with patients suffering from a rare human genetic disease, Fanconi anemia (FA), demonstrates the importance of FA genes. Over the course of human tumor development, FA genes perform critical tumor-suppression roles. In doing so, FA provides researchers with a unique genetic model system to study cancer etiology. Here, we review how aberrant function of the 22 FA genes and their signaling network contributes to malignancy. From this perspective, we will also discuss how the knowledge discovered from FA research serves basic and translational cancer research.

Fanconi anemia: myelodysplasia as a predictor of outcome

The adverse potential of the development of myelodysplastic syndrome (MDS) in Fanconi anemia (FA) was examined in a retrospective study of 41 FA patients who had bone marrow morphology and chromosomes reviewed by a single group. Thirty-three patients had adequate cytogenetic studies, and 16 (48%) had one or more abnormal studies: nine initially, and seven more on follow-up. Cytogenetic clonal variation was frequent, including disappearance of clones, clonal evolution, and appearance of new clones. The estimated five-year survival with a cytogenetic clone is 0.40, compared to 0.94 without a clone. Morphologic myelodysplasia (MDS), independent of a cytogenetic clone, was found in 13/41 patients (32%). The estimated five-year survival with MDS is 0.09, versus 0.92 without MDS. Leukemia developed in three patients whose initial cytogenetic clones prior to leukemia were t(1;18), t(5;22) and monosomy 7; the one with t(1;18) also had MDS. Our results focus on marrow morphology, and suggest that morphologic MDS may be more important than classical cytogenetics in prediction of an adverse outcome.

Ocular and orbital manifestations of the inherited bone marrow failure syndromes: Fanconi anemia and dyskeratosis congenita

PURPOSE

The inherited bone marrow failure syndromes (IBMFS) are a heterogeneous group of genetic disorders that share the inability of the bone marrow to produce an adequate number of blood cells. The 4 most frequent syndromes are Fanconi anemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anemia (DBA), and Shwachman-Diamond syndrome (SDS). All 4 syndromes have been associated with various physical abnormalities. As part of a genotype/phenotype/cancer susceptibility study, we determined the prevalence of ophthalmic manifestations in these 4 syndromes.

DESIGN

Cross-sectional study of a patient cohort.

PARTICIPANTS

Seventy-five patients with an IBMFS and 121 of their first-degree relatives were seen in the National Eye Institute, National Institutes of Health, from 2001 to 2007. The patient group included 22 with FA, 28 with DC, 19 with DBA, and 6 with SDS.

METHODS

Every participant underwent a complete ophthalmic evaluation and digital facial photography with an adhesive paper ruler on the patient's forehead for an internal measure of scale. Interpupillary distance (IPD), inner canthal distance (ICD), outer canthal distance (OCD), palpebral fissure length (PFL), and corneal diameter (CD) were measured. Thirteen of the 22 patients with FA underwent axial length (AL) measurements by A-scan ultrasonography.

MAIN OUTCOME MEASURES

Type and prevalence of ophthalmic manifestations.

RESULTS

Ninety-five percent of patients with FA had at least 1 abnormal parameter, and 25% of patients had at least 4 abnormal parameters. Eighty-two percent of patients had small palpebral fissures, 69% of patients had simple microphthalmia, 64% of patients had small OCD, 55% of patients had microcornea, 28% of patients had ptosis, and 6% of patients had epicanthal folds. In patients with DC, abnormalities of the lacrimal drainage system (29%) were the most prevalent findings, followed by retinal abnormalities (pigmentary changes, retinal neovascularization, retinal detachment, exudative retinopathy) in 21%, cicatricial entropion with trichiasis and blepharitis in 7% each, and sparse eyelashes and congenital cataract in 3.5% each. No significant ophthalmic abnormalities were seen in patients with DBA or SDS.

CONCLUSIONS

Syndrome-specific ocular findings are associated with FA and DC and may antedate diagnosis of the specific syndrome. Early recognition of these abnormalities is important for optimal management.

Defective hematopoiesis and hepatic steatosis in mice with combined deficiencies of the genes encoding Fancc and Cu/Zn superoxide dismutase

Several lines of evidence point to an abnormality in the response of Fanconi anemia cells to reactive oxygen species. To investigate the potential pathologic consequences of an in vivo alteration of redox state in mice lacking one of the Fanconi anemia genes, animals were generated having combined deficiencies of the cytosolic Cu/Zn superoxide dismutase (Sod1) and Fanconi anemia complementation group C (Fancc) genes. Interestingly, hepatocytes of Fancc(-/-)Sod1(-/-) mice exhibited a zonal pattern of microvesicular steatosis, possibly as a result of oxidative stress-induced injury to hepatocyte membranes. Consistent with this idea, freshly explanted Fancc(-/-)Sod1(-/-) hepatocytes demonstrated increased spontaneous production of superoxide in vitro. The second phenotypic feature of Fancc(-/-) Sod1(-/-) mice was that of bone marrow hypocellularity accompanied by significant decreases in peripheral blood erythrocyte and leukocyte numbers as compared with wild-type controls. Although flow cytometry analysis with monoclonal antibodies against cell surface antigens revealed normal numbers of primitive hematopoietic progenitor populations in Fancc(-/-)Sod1(-/-) marrow, lineage-positive progenitor numbers were significantly reduced in these mice. Furthermore, the in vitro clonogenic growth of Fancc(-/-)Sod1(-/-) erythroid, myeloid, and early B-lymphoid colonies in semisolid media was profoundly compromised. These results suggested that the altered redox state likely present in Fancc(-/-) Sod1(-/-) hematopoietic progenitors was responsible for an impairment of cell proliferation or survival. (Blood. 2001;98:1003-1011)