Affiliations of authors: K. Offit, K. Mah, K. Nafa, M. Robson, N. Ellis (Clinical Genetics Service), L. Norton (Breast Cancer Medicine Service), Memorial Sloan-Kettering Cancer Center, New York, NY; O. Levran, S. D. Batish, R. Diotti, A. D. Auerbach, Laboratory of Human Genetics and Hematology, The Rockefeller University, New York; B. Mullaney, A. Deffenbaugh, T. Scholl, Myriad Genetic Laboratories, Inc., Salt Lake City, UT; H. Schneider, H. Hanenberg, Department of Pediatric Oncology, Hematology and Immunology, Heinrich-Heine University Medical Center, Düsseldorf, Germany; V. K. Proud, Division of Medical Genetics, Childrens Hospital of The Kings Daughters, Norfolk, VA.
Correspondence to: Kenneth Offit, MD, MPH, Clinical Genetics Service, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10021 (e-mail: offitk{at}mskcc.org).
ABSTRACT
Fanconi anemia is an inherited disease characterized by bone marrow failure, congenital malformations, and predisposition to cancer. The breast cancer susceptibility gene BRCA2 was recently found to be associated with Fanconi anemia complementation group D1 (FA-D1). We examined four kindreds afflicted with Fanconi anemia for the presence of germline BRCA2 mutations. One kindred, of Ashkenazi Jewish ancestry, had five members who were diagnosed with breast cancer and two cousins who were BRCA2*6174delT/C3069X compound heterozygotes and had Fanconi anemia and brain tumors. In another kindred of Ashkenazi Jewish and Lithuanian Catholic ancestry, a child with Fanconi anemia and a medulloblastoma was a BRCA2*6174delT/886delGT compound heterozygote. Two other kindreds each contained a Fanconi anemiaafflicted child who developed medulloblastoma; one child was of Latin American ancestry and a compound heterozygote for BRCA2*I2490T/ 5301insA and the other was African American and a compound heterozygote for BRCA2*Q3066X/E1308X. Median age of the Fanconi anemiaafflicted children at brain tumor diagnosis was 3.5 years. The co-occurrence of brain tumors, Fanconi anemia, and breast cancer observed in one of these kindreds constitutes a new syndromic association. Individuals who carry a germline BRCA2 mutation and who plan to have children with a partner of Ashkenazi Jewish descent should consider undergoing genetic counseling.
The kindreds described in this report were enrolled in the International Fanconi Anemia Registry (IFAR), a research study at The Rockefeller University (New York, NY). The study was approved by the Institutional Review Board of The Rockefeller University, and all subjects provided written informed consent. Medical and family histories were obtained by direct interview. The pedigree shown in Fig. 1 was modified to preserve the confidentiality of the family members. As part of the IFAR study (3,4), blood was collected from all family members, and genomic DNA was extracted for mutational analyses by standard methods. Fibroblasts were isolated from skin biopsy samples obtained from selected patients and used for correction of cross-link hypersensitivity assays. As part of the IFAR study, linkage analysis was performed using microsatellite markers flanking the Fanconi anemia complementation group A locus (FANCA) on chromosome 16q24.3 (5). In selected kindreds (e.g., kindred 3), we excluded Fanconi anemia complementation groups FA-A, FA-C, FA-D2, FA-E, FA-F, and FA-G by examining the correction of cross-link hypersensitivity in patients fibroblasts that had been transduced with retroviral vectors containing wild-type FANCA, FANCC, FANCD2, FANCE, FANCF, or FANCG complementary DNAs as previously described (6). Analysis of the coding regions and intron/exon junctions of BRCA2 was performed by direct DNA sequencing (Myriad Genetic Laboratories, Salt Lake City, UT) or allele-specific analysis of genomic DNA (7). Pathology reports or medical record documentation of tissue diagnosis was available for all individuals diagnosed with Fanconi anemia except the proband in kindred 1, who underwent no autopsy.
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Kindreds 3 and 4, which were of Latin American and African American ancestry, respectively, each included a girl with Fanconi anemia who developed medulloblastoma at age 2.5 years and 3.5 years, respectively. The members of kindred 3 were not in Fanconi anemia complementation groups FA-A, FA-C, FA-D2, FA-E, FA-F, or FA-G. The Fanconi anemiaaffected children in kindreds 3 and 4 were compound heterozygotes for BRCA2*I2490T/5301insA and BRCA2*Q3066X/E1308X, respectively.
We have previously reported that the carrier frequency of the breast and ovarian cancerpredisposing mutation BRCA2*6174delT is approximately 1 in 100 among individuals of Ashkenazi Jewish heritage (9). We believe that the second mutation identified in kindred 1, BRCA2*9435T>A (C3069X), is also likely to be associated with an increased risk of breast cancer because another BRCA2 protein-truncating mutation located further downstream of C3069X, Y3308X, is associated with breast cancer (10). Two other protein-truncating alleles of BRCA2, 9900insA and 7691insAT, have been detected in a cell line derived from a Fanconi anemia patient in complementation group FA-D1 (2). However, in that report, family histories of breast and ovarian cancers of the patients from which that cell line and several other cell lines were derived are not known because medical records were not available (2).
It has been assumed that in humans, as in mice, homozygous mutations of BRCA2 result in embryonic lethality (10). The phenotypes of human BRCA2 compound heterozygotes are less well defined. In four of the five cases of Fanconi anemia reported here, and in one compound heterozygote previously reported (2), the presence of one protein-truncating BRCA2 allele may allow for partial activity of BRCA2 and expression of the Fanconi anemia phenotype. The common polymorphism BRCA2*ter3326 results in a carboxyl-terminal protein truncation because of the presence of a premature stop codon at amino acid 3326 (11). The identification of this polymorphism in a cell line derived from a Fanconi anemia patient in complementation group FA-B who was a BRCA2 compound heterozygote (2) suggests a pathogenic role for this allele. We reviewed the results of BRCA1 and BRCA2 mutation tests conducted at a single reference laboratory in Salt Lake City, Utah, on more than 10 000 members of breast cancer kindreds and found that 47 patients carried both the BRCA2*K3326X allele and another protein-truncating, and presumably disease-causing, BRCA2 mutation (supplemental data, available at http://jncicancerspectrum.oupjournals.org/jnci/content/vol95/issue20/). Because of the very low frequency at which this allele co-segregates with most of the other protein-truncating mutations observed, we predict that the majority of the dual mutation combinations observed occur in the trans configuration; none of the 47 patients had an unusual phenotype noted in the medical information provided by their physicians. The I2490T allele of BRCA2 that we detected in kindred 3 has been reported in more than 70 individuals of Latin American ancestry who were either unaffected or affected by breast cancer and is classified as a variant of unknown clinical significance in the Breast Cancer Information Core database (10). On the basis of these observations, we do not believe that the BRCA2*I2490T and BRCA2*K3326X alleles are likely to be pathogenic. We propose instead that an unidentified BRCA2 mutation or a mutation in another gene may have also been present in the kindreds with members who were compound heterozygotes for the BRCA2*I2490T (this report) or for the BRCA2*K3326X allele (2).
These findings provide the rationale for offering genetic counseling to individuals who carry a germline BRCA2 mutation and who plan to have children with a partner of Ashkenazi Jewish descent. Among Ashkenazi Jewish kindreds, numerous BRCA2 protein-truncating alleles, including BRCA2*9325insA, have been reported in the 3' region surrounding nucleotide 9435 (10,12,13). For example, the BRCA*886delGT allele detected in the maternal lineage of kindred 2 has been observed 12 times in the Breast Cancer Information Core database (10). Thus, although the probability of an Ashkenazi Jewish carrier of the BRCA2*6174delT mutation having offspring with a carrier of another BRCA2 mutation is quite low, the possibility that such a couple could have offspring with Fanconi anemia has now been documented in this study. In addition, for individuals known to carry BRCA2 mutations, particularly mutations that result in a carboxyl-terminal protein truncation, the approximately 1% probability of the spouse (if of Ashkenazi Jewish descent) carrying a BRCA2*6174delT mutation (9) and the potential 25% risk of having an offspring with Fanconi anemia suggest that genetic counseling in this setting may be indicated.
Although there is no increased occurrence of brain cancers in kindreds with heterozygous BRCA2 mutations (14), both medulloblastomas and astrocytomas have been reported in rare cases of Fanconi anemia (1,4,1517). The five cases of Fanconi anemia and brain tumors analyzed for BRCA2 mutations in this study represent five of the six such cases reported to the IFAR. The finding of BRCA2 mutations in five children with Fanconi anemia and brain tumors, predominantly medulloblastomas, is distinctive and constitutes a new syndromic association. The close interactions between the FANC and BRCA2 gene products and other cell-cycle checkpoint or DNA-damage response proteins, including ATM, BRCA1, NBS1, CHEK2, and RAD51, suggest possible mechanisms for the molecular pathogenesis of the brain tumors observed in these and possibly other kindreds (18).
NOTES
B. Mullaney holds stock options in Myriad Genetics (Salt Lake City, UT), which performs clinical testing for BRCA1 and BRCA2 mutations.
Present address: Brian Mullaney, Bristol-Myers Squibb, Clinical Oncology, Pharmaceutical Research Institute, Wallingford, CT.
Supported by Public Health Service grant R37HL32987 (to A. D. Auerbach) from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services. Also supported by the Lymphoma Foundation; the Danziger Foundation; the Koodish Fellowship; the Goldsmith Research Project; the Lomangino, Weissenbach, Southworth, and Niehaus Family Research Funds; the Elterninitiative Kinderkrebsklinik e.V.; and the Kinderstern e.V.
We are grateful to Beth Rapaport, Prema Kolachana, and Tomas Kirchhoff for technical assistance and to Judy Hull and Lauren Scheuer for counseling one of the kindreds.
REFERENCES
1 Kutler DI, Singh B, Satagopan J, Batish SD, Berwick M, Giampietro PF, et al. A 20-year perspective of the International Fanconi Anemia Registry (IFAR). Blood 2003;101:124956.
2 Howlett NG, Taniguchi T, Olson S, Cox B, Waisfisz Q, De Die-Smulders C, et al. Biallelic inactivation of BRCA2 in Fanconi anemia. Science 2002;297:6069.
3 Verlander PC, Kaporis A, Liu Q, Zhang Q, Seligsohn U, Auerbach AD. Carrier frequency of the IVS4 +4 A-->T mutation of the Fanconi anemia gene FAC in the Ashkenazi Jewish population. Blood 1995;86:40348.
4 Giampietro PF, Adler-Brecher B, Verlander PC, Pavlakis SG, Davis JG, Auerbach AD. The need for more accurate and timely diagnosis in Fanconi anemia. A report from the International Fanconi Anemia Registry. Pediatrics 1993;91:111620.[Abstract]
5 Positional cloning of the Fanconi anaemia group A gene. The Fanconi Anemia/Breast Cancer Consortium. Nat Genet 1996;14:3248.[ISI][Medline]
6 Hanenberg H, Batish SD, Pollok KE, Vieten L, Leurs C, Cooper RJ, et al. Phenotypic correction of primary T cells from patients with Fanconi anemia with retroviral vectors as a diagnostic tool. Exp Hematol 2002;30:41020.[CrossRef][ISI][Medline]
7 Neuhausen S, Gilewski T, Norton L, Tran T, McGuire P, Swensen J, et al. Recurrent BRCA2 6174delT mutations in Ashkenazi Jewish women affected by breast cancer. Nat Genet 1996;13:1268.[ISI][Medline]
8 Auerbach AD, Pujara K, Greenbaum J, Batish SD, Verlander PC, Levran O. Spectrum of sequence variation in the FANCG gene: an International Fanconi Anemia Registry (IFAR) study. Hum Mutat 2003;21:15868.[CrossRef][ISI][Medline]
9 Oddoux C, Struewing JP, Clayton CM, Neuhausen S, Brody LC, Kaback M, et al. The carrier frequency of the BRCA2 6174delT mutation among Ashkenazi Jewish individuals is approximately 1%. Nat Genet 1996;14:18890.[ISI][Medline]
10 National Human Genome Research Institute (NHGRI). An open access on-line breast cancer mutation data base: an international collaborative effort hosted by NHGRI. Available at: http://research.nhgri.nih.gov/bic/. [Last accessed August 18, 2003.]
11 Ludwig T, Chapman DL, Papaioannou VE, Efstratiadis A. BRCA2 is required for embryonic cellular proliferation in the mouse. Genes Dev 1997;11:124252.[Abstract]
12 Mazoyer S, Dunning AM, Serova O, Dearden J, Puget N, Healey CS, et al. A polymorphic stop codon in BRCA2. Nat Genet 1996;14:2534.[ISI][Medline]
13 Kauff ND, Perez-Segura P, Robson ME, Scheuer L, Siegel B, Schluger A, et al. Incidence of non-founder BRCA1 and BRCA2 mutations in high risk Ashkenazi breast and ovarian cancer families. J Med Genet 2002;39:6114.
14 Ramus SJ, Kote-Jarai Z, Friedman LS, van der Looij M, Gayther SA, Csokay B, et al. Analysis of BRCA1 and BRCA2 mutations in Hungarian families with breast or breast-ovarian cancer. Am J Hum Genet 1997;60:12426.[ISI][Medline]
15 Cancer risks in BRCA2 mutation carriers. The Breast Cancer Linkage Consortium. J Natl Cancer Inst 1999;91:13106.
16 de Chadarevian JP, Vekemans M, Bernstein M. Fanconis anemia, medulloblastoma, Wilms tumor, horseshoe kidney, and gonadal dysgenesis. Arch Pathol Lab Med 1985;109:3679.[ISI][Medline]
17 Ruud E, Wesenberg F. Microcephalus, medulloblastoma and excessive toxicity from chemotherapy: an unusual presentation of Fanconi anaemia. Acta Paediatr 2001;90:5803.[ISI][Medline]
18 DAndrea AD, Grompe M. The Fanconi anaemia/BRCA pathway. Nat Rev Cancer 2003;3:2334.[CrossRef][ISI][Medline]
Manuscript received April 21, 2003; revised August 11, 2003; accepted August 15, 2003.
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