TY - JOUR A1 - Karastaneva, Anna A1 - Lanz, Sofia A1 - Wawer, Angela A1 - Behrends, Uta A1 - Schindler, Detlev A1 - Dietrich, Ralf A1 - Burdach, Stefan A1 - Urban, Christian A1 - Benesch, Martin A1 - Seidel, Markus G. T1 - Immune thrombocytopenia in two unrelated Fanconi anemia patients - a mere coincidence? JF - Frontiers in Pediatrics N2 - Thrombocytopenia and pancytopenia, occurring in patients with Fanconi anemia (FA), are interpreted either as progression to bone marrow failure or as developing myelodysplasia. On the other hand, immune thrombocytopenia (ITP) represents an acquired and often self-limiting benign hematologic disorder, associated with peripheral, immune-mediated, platelet destruction requiring different management modalities than those used in congenital bone marrow failure syndromes, including FA. Here, we describe the clinical course of two independent FA patients with atypical – namely immune – thrombocytopenia. While in one patient belonging to complementation group FA-A, the ITP started at 17 months of age and showed a chronically persisting course with severe purpura, responding well to intravenous immunoglobulins (IVIG) and later also danazol, a synthetic androgen, the other patient (of complementation group FA-D2) had a self-limiting course that resolved after one administration of IVIG. No cytogenetic aberrations or bone marrow abnormalities other than FA-typical mild dysplasia were detected. Our data show that acute and chronic ITP may occur in FA patients and impose individual diagnostic and therapeutic challenges in this rare congenital bone marrow failure/tumor predisposition syndrome. The management and a potential context of immune pathogenesis with the underlying marrow disorder are discussed. KW - immune thrombocytopenia KW - bone marrow failure syndrome KW - Evans syndrome KW - danazol KW - FANCA KW - FANCD2 KW - Fanconi anemia KW - DNA repair defect Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149837 VL - 3 IS - 50 ER - TY - JOUR A1 - Rickman, Kimberly A. A1 - Lach, Francis P. A1 - Abhyankar, Avinash A1 - Donovan, Frank X. A1 - Sanborn, Erica M. A1 - Kennedy, Jennifer A. A1 - Sougnez, Carrie A1 - Gabriel, Stacey B. A1 - Elemento, Olivier A1 - Chandrasekharappa, Settara C. A1 - Schindler, Detlev A1 - Auerbach, Arleen D. A1 - Smogorzewska, Agata T1 - Deficiency of UBE2T, the E2 Ubiquitin Ligase Necessary for FANCD2 and FANCI Ubiquitination, Causes FA-T Subtype of Fanconi Anemia JF - Cell Reports N2 - Fanconi anemia (FA) is a rare bone marrow failure and cancer predisposition syndrome resulting from pathogenic mutations in genes encoding proteins participating in the repair of DNA interstrand crosslinks (ICLs). Mutations in 17 genes (FANCA-FANCS) have been identified in FA patients, defining 17 complementation groups. Here, we describe an individual presenting with typical FA features who is deficient for the ubiquitin-conjugating enzyme (E2), UBE2T. UBE2T is known to interact with FANCL, the E3 ubiquitin-ligase component of the multiprotein FA core complex, and is necessary for the monoubiquitination of FANCD2 and FANCI. Proband fibroblasts do not display FANCD2 and FANCI monoubiquitination, do not form FANCD2 foci following treatment with mitomycin C, and are hypersensitive to crosslinking agents. These cellular defects are complemented by expression of wild-type UBE2T, demonstrating that deficiency of the protein UBE2T can lead to Fanconi anemia. UBE2T gene gains an alias of FANCT. KW - cross-link repair KW - DNA repair KW - gene KW - mutations KW - aldehydes KW - somatic mosaicism KW - pathway KW - monoubiquitination KW - diagnosis KW - proteins Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151525 VL - 12 SP - 35 EP - 41 ER -