A genetic association study of the CLEC12A gene in rheumatoid arthritis
JOINT BONE SPINE
Authors: Michou, Laetitia; Cornelis, Francois; Levesque, Jean-Michel; Bombardieri, Stefano; Balsa, Alejandro; Westhovens, Rene; Barrera, Pilar; Alves, Helena; van de Putte, Leo; Migliorini, Paola; Bardin, Thomas; Petit-Teixeira, Elisabeth; Fernandes, Maria J. G.
Abstract
Objective: The CLEC12A gene codes for an immune inhibitory receptor that maps to 12p13.2. Since an increase in CLEC12A mRNA correlates with rheumatoid factor values greater than 40 IU/ml in rheumatoid fibroblast-like synovial cells, this study assessed the potential of an association between CLEC12A and rheumatoid arthritis (RA) using a phenotype-based approach. Methods: A discovery cohort of Western European ethnicity was genotyped for eight tag single nucleotide polymorphisms. Statistical analyses relied on the transmission disequilibrium test, relative risk and 95% confidence interval (CI) calculations. Observed haplotype frequencies were compared to expected frequencies using a family-based association test. Statistically significant associations were further tested in a second cohort of unrelated West-European RA patients. Results: An overtransmission of the C allele of the rs1323461 tag single nucleotide polymorphism was observed (56.6% of allele C transmission, P = 0.046) in the discovery cohort. The relative risk of the AC and CC genotypes when compared to the AA genotype was high (relative risk = 4.08; 95% CI: 1.52-10.95, uncorrected P = 2.1 x 10-3), particularly in the subgroup of erosive RA (relative risk = 5.27; 95% CI: 1.53-18.19, uncorrected P = 2.1 x 10(-3)), both remaining statistically significant after conservative Bonferroni's correction. The CGAGCCGA haplotype was observed more frequently than expected (P = 0.013). In the second cohort, the C allele had a tendency to be more frequent in RA patients (82.4%) than controls (79.2%) (P = 0.069). Conclusion: We report a potential genetic association of CLEC12A with RA. Since CLEC12A encodes for the myeloid inhibitory C- type lectin- like receptor that modulates cytokine synthesis, this receptor may contribute to the pathogenesis of RA. (C) 2012 Societe francaise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.
Identification of novel cluster groups in pediatric high-risk B-precursor acute lymphoblastic leukemia with gene expression profiling: correlation with genome-wide DNA copy number alterations, clinical characteristics, and outcome
BLOOD
Authors: Harvey, Richard C.; Mullighan, Charles G.; Wang, Xuefei; Dobbin, Kevin K.; Davidson, George S.; Bedrick, Edward J.; Chen, I-Ming; Atlas, Susan R.; Kang, Huining; Ar, Kerem; Wilson, Carla S.; Wharton, Walker; Murphy, Maurice; Devidas, Meenakshi; Carroll, Andrew J.; Borowitz, Michael J.; Bowman, W. Paul; Downing, James R.; Relling, Mary; Yang, Jun; Bhojwani, Deepa; Carroll, William L.; Camitta, Bruce; Reaman, Gregory H.; Smith, Malcolm; Hunger, Stephen P.; Willman, Cheryl L.
Abstract
To resolve the genetic heterogeneity within pediatric high-risk B-precursor acute lymphoblastic leukemia (ALL), a clinically defined poor-risk group with few known recurring cytogenetic abnormalities, we performed gene expression profiling in a cohort of 207 uniformly treated children with high-risk ALL. Expression profiles were correlated with genome-wide DNA copy number abnormalities and clinical and outcome features. Unsupervised clustering of gene expression profiling data revealed 8 unique cluster groups within these high-risk ALL patients, 2 of which were associated with known chromosomal translocations (t(1;19)(TCF3-PBX1) or MLL), and 6 of which lacked any previously known cytogenetic lesion. One unique cluster was characterized by high expression of distinct outlier genes AGAP1, CCNJ, CHST2/7, CLEC12A/B, and PTPRM; ERG DNA deletions; and 4-year relapse-free survival of 94.7% +/- 5.1%, compared with 63.5% +/- 3.7% for the cohort (P = .01). A second cluster, characterized by high expression of BMPR1B, CRLF2, GPR110, and MUC4; frequent deletion of EBF1, IKZF1, RAG1-2, and IL3RA-CSF2RA; JAK mutations and CRLF2 rearrangements (P < .0001); and Hispanic ethnicity (P < .001) had a very poor 4-year relapse-free survival (21.0% +/- 9.5%; P < .001). These studies reveal striking clinical and genetic heterogeneity in high-risk ALL and point to novel genes that may serve as new targets for diagnosis, risk classification, and therapy. (Blood. 2010;116(23):4874-4884)