A novel diagnostic screen for defects in the Fanconi anemia pathway.
Fanconi anemia (FA) is an autosomal recessive chromosomal instability syndrome characterized by congenital abnormalities, progressive bone marrow failure, and cancer predisposition. Although patients with FA are candidates for bone marrow transplantation or gene therapy, their phenotypic heterogeneity can delay or obscure diagnosis. The current diagnostic test for FA consists of cytogenetic quantitation of chromosomal breakage in response to diepoxybutane (DEB) or mitomycin C (MMC). Recent studies have elucidated a biochemical pathway for Fanconi anemia that culminates in the monoubiquitination of the FANCD2 protein. In the current study, we develop a new rapid diagnostic and subtyping FA assay amenable for screening broad populations at risk of FA. Primary lymphocytes were assayed for FANCD2 monoubiquitination by immunoblot. The absence of the monoubiquitinated FANCD2 isoform correlated with the diagnosis of FA by DEB testing in 11 known patients with FA, 37 patients referred for possible FA, and 29 healthy control subjects. Monoubiquitination of FANCD2 was normal in other bone marrow failure syndromes and chromosomal breakage syndromes. A combination of retroviral gene transfer and FANCD2 immunoblotting provides a rapid subtyping assay for patients newly diagnosed with FA. These new FA screening assays would allow efficient testing of broad populations at risk.
Shimamura
Akiko
A
Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA. akiko_shimamura@dfci.harvard.edu
Montes de Oca
Rocio
R
Svenson
John L
JL
Haining
Nicholas
N
Moreau
Lisa A
LA
Nathan
David G
DG
D'Andrea
Alan D
AD
D015153:Blotting, Western; D001855:Bone Marrow Diseases / Q000097:blood; D002461:Cell Line, Transformed; D019457:Chromosome Breakage; D002877:Chromosomes, Human / Q000187:drug effects; D018076:DNA, Complementary / Q000235:genetics; D004852:Epoxy Compounds / Q000494:pharmacology; D005199:Fanconi Anemia / Q000097:blood / Q000145:classification / Q000175:diagnosis / Q000235:genetics*; D052236:Fanconi Anemia Complementation Group D2 Protein; D018740:Genetic Heterogeneity; D005820:Genetic Testing; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D016685:Mitomycin / Q000494:pharmacology; D009687:Nuclear Proteins / Q000097:blood* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012190:Retroviridae / Q000235:genetics; D014162:Transfection; D025801:Ubiquitin / Q000378:metabolism
D018076:DNA, Complementary; D004852:Epoxy Compounds; C499905:FANCD2 protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D009687:Nuclear Proteins; D025801:Ubiquitin; D016685:Mitomycin; C007366:diepoxybutane