Fanconi anemia (FA) is a rare inherited disorder clinically characterized by congenital malformations, progressive bone marrow failure and cancer susceptibility. At the cellular level, FA is associated with hypersensitivity to DNA-crosslinking genotoxins. Eight of 17 known FA genes assemble the FA E3 ligase complex, which catalyzes monoubiquitination of FANCD2 and is essential for replicative DNA crosslink repair. Here, we identify the first FA patient with biallelic germline mutations in the ubiquitin E2 conjugase UBE2T. Both mutations were aluY-mediated: a paternal deletion and maternal duplication of exons 2–6. These loss-of-function mutations in UBE2T induced a cellular phenotype similar to biallelic defects in early FA genes with the absence of FANCD2 monoubiquitination. The maternal duplication produced a mutant mRNA that could encode a functional protein but was degraded by nonsense-mediated mRNA decay. In the patient's hematopoietic stem cells, the maternal allele with the duplication of exons 2–6 spontaneously reverted to a wild-type allele by monoallelic recombination at the duplicated aluY repeat, thereby preventing bone marrow failure. Analysis of germline DNA of 814 normal individuals and 850 breast cancer patients for deletion or duplication of UBE2T exons 2–6 identified the deletion in only two controls, suggesting aluY-mediated recombinations within the UBE2T locus are rare and not associated with an increased breast cancer risk. Finally, a loss-of-function germline mutation in UBE2T was detected in a high-risk breast cancer patient with wild-type BRCA1/2. Cumulatively, we identified UBE2T as a bona fide FA gene (FANCT) that also may be a rare cancer susceptibility gene.
ning Studies for Rare Thrombotic and Hemostatic Disorders (U34) (RFA-HL-12-023) and the NHLBI Clinical Trial Pilot Studies (R34) (PAR-10-005) awards.You may find more information for this FOA at: http://grants.nih.gov/ grants/guide/rfa-files/RFA-HL-12-016.html.The NHLBI also has a program for NHLBI Clinical Trial Pilot Studies (R34), PAR-10-005, which supports pilot studies to obtain data critical for the design of robust clinical trials. Additional information is at: http://grants.-nih.gov/grants/guide/pa-files/PAR-10-005.html.In addition, NHLBI continues the program for Ancillary Studies in Clinical Trials (R01), RFA-HL-12-012, which is for the conduct of time-sensitive ancillary studies related to heart, lung and blood diseases and sleep disorders in conjunction with ongoing clinical trials. Additional information is at: http:// grants.nih.gov/grants/guide/rfa-files/RFA-HL-12-012.html.
Severe congenital neutropenia a clinically and genetically heterogeneous disorder. Mutations in different genes have been described as causative for severe neutropenia, e.g. ELANE, HAX1 and G6PC3. Although congenital neutropenia is considered to be a group of monogenic disorders, the phenotypic heterogeneity even within the yet defined genetic subtypes points to additional genetic and/or epigenetic influences on the disease phenotype. We describe congenital neutropenia patients with mutations in two candidate genes each, including 6 novel mutations. Two of them had a heterozygous ELANE mutation combined with a homozygous mutation in G6PC3 or HAX1, respectively. The other 2 patients combined homozygous or compound heterozygous mutations in G6PC3 or HAX1 with a heterozygous mutation in the respective other gene. Our results suggest that digenicity may underlie this disorder of myelopoiesis at least in some congenital neutropenia patients.
Improvements in proteome analysis of erythrocyte membrane proteins by two-dimensional electrophoresis are here reported. In particular, a differential extraction procedure was set up allowing separation of integral membrane proteins from peripheral species. Moreover, the use of dilute Immobiline gels (down to as low as 3% T matrix) permitted a better penetration and transfer inside the gel of proteins with large M(r). These protocol modifications, combined with sample delipidation and alkylation prior to electrophoresis, which prevented generation of homo- and hetero-oligomers following disulfide scrambling phenomena, allowed the display of more than 500 spots in the pI/M(r) plane. Among those, noteworthy was the presence of high levels of filamentous proteins, such as alpha-spectrin and ankyrins, or integral membrane proteins, such as band 3, band 4.1 and 4.2, not displayed or barely present in other maps exploiting immobilized pH gradients in the first dimension. Accordingly, our results show that this 2D mapping technique is a valuable tool in exploring pathologies related to genetic defects associated to membrane proteins.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.