ABSTRACT
A recent genome-wide association study of chronic lymphocytic leukaemia (CLL) has identified a susceptibility locus on 6p25.3 associated with a modest but highly significant increase in CLL risk. Using a set of single nucleotide polymorphism (SNP) markers, we generated a fine-scale map and narrowed the association signal to a 18 kb DNA segment within the 3'-untranslated region (UTR) of the IRF4 (interferon regulatory factor 4) gene. Resequencing this segment in European subjects identified 55 common polymorphisms, including 13 highly correlated candidate causal variants. In a large case-control study, it was shown that all but four variants could be excluded with 95% confidence. These four SNPs map to a 3 kb region of the 3'-UTR of IRF4, consistent with the causal basis of the association being mediated through differential IRF4 expression.
Subject(s)
Chromosome Mapping , Chromosomes, Human, Pair 6/genetics , Genetic Predisposition to Disease/genetics , Interferon Regulatory Factors/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , 3' Untranslated Regions/genetics , Base Sequence , Case-Control Studies , Computational Biology , Female , Genome-Wide Association Study , Humans , Male , Molecular Sequence Data , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA , Utah , White People/geneticsABSTRACT
Monoclonal B-cell lymphocytosis (MBL) is detectable in > 3% of the general population. Recent data are compatible, at least in a proportion of cases, with MBL being a progenitor lesion for chronic lymphocytic leukemia (CLL) and a surrogate for inherited predisposition. Common single nucleotide polymorphisms (SNPs) at 2q13 (rs17483466), 2q37.1 (rs13397985), 2q37.3 (rs757978), 6p25.3 (rs872071), 8q24.21 (rs2456449), 11q24.1 (rs735665), 15q21.3 (rs7169431), 15q23 (rs7176508), 16q24.1 (rs305061), and 19q13.32 (rs11083846) have been shown to confer a modest but significant increase in CLL risk. To examine the impact of these 10 SNPs on MBL, we analyzed 3 case-control series totaling 419 cases and 1753 controls. An association between genotype and MBL risk was seen for 9 SNPs, 6 of which were statistically significant: rs17483466 (odds ratio [OR] =1.27; P = .02), rs13397985 (OR = 1.40; P = 1.72 × 10(-3)), rs757978 (OR = 1.38; P = .02), rs872071 (OR = 1.27; P = 7.75 × 10(-3)), rs2456449 (OR = 1.31; P = 3.14 × 10(-3)), and rs735665 (OR = 1.63; P = 6.86 × 10(-6)). Collectively, these data provide support for genetic variation influencing CLL risk through predisposition to MBL.
Subject(s)
B-Lymphocytes/pathology , Chromosome Aberrations , Chromosomes, Human/genetics , Genetic Predisposition to Disease , Lymphocytosis/genetics , Polymorphism, Single Nucleotide/genetics , Aged , Case-Control Studies , Female , Genotype , Humans , Lymphocytosis/pathology , MaleABSTRACT
Chronic lymphocytic leukaemia (CLL) is the most common form of lymphoid malignancy in Western countries, accounting for around a quarter of all leukaemias. Evidence from epidemiological and family studies have provided evidence for familial clustering of CLL compatible with inherited genetic predisposition to CLL. Direct evidence for genetic susceptibility has been provided by a recent genome wide association study of CLL which has identified common variants at 10 different loci which influence CLL risk. Here we review the current knowledge regarding the allelic architecture of susceptibility to CLL and what the currently identified risk loci are telling us regarding disease aetiology.
Subject(s)
Genetic Variation , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Chromosome Aberrations , Genetic Loci , Genetic Predisposition to Disease , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/epidemiology , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Risk FactorsABSTRACT
A genome-wide association study of chronic lymphocytic leukaemia (CLL) suggested that common variants at 15q25.2 (rs783540) and 18q21.1 (rs1036935) influence CLL. To validate these associations and explore their relationship with CLL risk we genotyped case-control datasets from Poland, UK and Italy totalling 1428 cases and 1920 controls. Combined data from these and previously genotyped series (2503 cases and 5789 controls) provided evidence for an association between 15q25.2 and 18q21.1 loci and CLL risk (P(combined) = 1·10 × 10(-7) and 1·30 × 10(-5) respectively). These data provide further evidence for the involvement of common genetic variants in CLL risk and insight into the biological basis of disease development.
Subject(s)
Chromosomes, Human, Pair 15/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Aged , Case-Control Studies , Chromosomes, Human, Pair 18/genetics , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotype , Humans , Male , Middle Aged , Polymorphism, Single NucleotideABSTRACT
A genome-wide linkage scan has provided evidence for a chronic lymphocytic leukemia (CLL) susceptibility locus at 2q21 to which the chemokine receptor CXCR4 gene maps. Recent data provide some evidence for common variation in CXCR4 according to the polymorphic variant rs2228014 defining CLL risk. To examine the role of genetic variation in CXCR4 on CLL risk, we screened 188 familial CLL cases and 213 controls for germline mutations in the coding regions of CXCR4 and genotyped rs2228014 in 1058 CLL cases and 1807 controls. No association between rs2228014 and risk of CLL was seen (P = .83). One truncating (W195X) and 2 missense mutations with possible functional consequences (V139I and G335S) were identified among 186 familial cases and 0 in 213 controls sequenced. Our analysis provides no evidence that common variation in CXCR4 defined by rs228014 influences the risk of CLL, but that functional coding mutations in CXCR4 may contribute to familial CLL.
Subject(s)
Genetic Variation , Germ-Line Mutation , Leukemia, Lymphocytic, Chronic, B-Cell/epidemiology , Receptors, CXCR4/genetics , Codon, Nonsense , DNA Mutational Analysis , Gene Frequency , Genotype , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Mutation, Missense , Receptors, CXCR4/physiology , RiskABSTRACT
BACKGROUND: There is variability in the outcome of patients with chronic lymphocytic leukemia with apparently the same stage of disease. Identifying genetic variants that influence patients' outcome and response to treatment may provide important insights into the biology of the disease. DESIGN AND METHODS: We investigated the possibility that genetic variation influences outcome by conducting a genome-wide analysis of 346,831 single nucleotide polymorphisms in 356 patients entered into a phase III trial comparing the efficacy of fludarabine, chlorambucil, and fludarabine with cyclophosphamide as first-line treatment. Genotypes were linked to individual patients' outcome data and response to chemotherapy. The association between genotype and progression-free survival was assessed by Cox regression analysis adjusting for treatment and clinicopathology. RESULTS: The strongest associations were shown for rs1949733 (ACOX3; P=8.22x10-7), rs1342899 (P=7.72×10(-7)) and rs11158493 (PPP2R5E; P=8.50×10(-7)). In addition, the 52 single nucleotide polymorphisms associated at P<10(-4) included rs438034 (CENPF; P=4.86×10(-6)), previously correlated with cancer progression, and rs2255235 (B2M; P=3.10×10(-5)) and rs2064501 (IL22RA2; P=4.81×10(-5)) which map to B-cell genes. CONCLUSIONS: Our findings provide evidence that genetic variation is a determinant of progression-free survival of patients with chronic lymphocytic leukemia. Specific associations warrant further analyses.
Subject(s)
Genotype , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/mortality , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Female , Gene Expression Regulation, Leukemic , Genotyping Techniques , Humans , Kaplan-Meier Estimate , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Male , Middle Aged , Neoplasm Staging , Protein Phosphatase 2/genetics , Quality Control , RNA, Messenger , Reproducibility of ResultsABSTRACT
A recent genome wide association study of chronic lymphocytic leukaemia (CLL) provided evidence that common variation at 2q13 (rs17483466), 2q37.1 (rs13397985), 6p25.3 (rs872071), 11q24.1 (rs735665), 15q23 (rs7176508) and 19q13.32 (rs11083846) affects CLL risk. To verify and further explore the relationship between these variants and CLL risk we genotyped case-control datasets from Spain and Sweden (824 cases, 850 controls). Combined data provided statistically significant support for an association between genotypes at rs13397985, rs872071, rs735665, rs7176508 and rs11083846 and CLL risk. CLL risk increased with increasing numbers of risk alleles (P(trend) = 1.40 x 10(-15)), consistent with a polygenic model of disease susceptibility. These data validate the relationship between common variation and risk of CLL.
Subject(s)
Chromosome Aberrations , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Aged , Case-Control Studies , Chromosomes, Human, Pair 11/genetics , Chromosomes, Human, Pair 15/genetics , Chromosomes, Human, Pair 19/genetics , Chromosomes, Human, Pair 2/genetics , Chromosomes, Human, Pair 6/genetics , Female , Gene Frequency , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotype , Humans , Male , Middle Aged , Polymorphism, Single NucleotideABSTRACT
To address the proposition that familial B-cell chronic lymphocytic leukemia (CLL) may exhibit a more restricted phenotype than sporadic CLL with respect to immunoglobulin gene usage or ontogenic development, we compared immunoglobulin (Ig) heavy chain variable region (VH) gene usage and IgVH mutation status in 327 patients with CLL from 214 families with 724 patients with sporadic cases. The frequency of mutated CLL was higher in familial CLL (P < .001), and there was evidence of intrafamilial concordance in mutation status (P < .001). The repertoire and frequency of IgVH usage was, however, not significantly different between familial and sporadic CLL. Furthermore, IgVH usage was not correlated between affected members of the same family. These observations provide evidence that familial CLL is essentially indistinguishable from sporadic CLL, favoring a genetic basis to disease development in general rather than a simple environmental etiology.
Subject(s)
Immunoglobulin Variable Region/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/etiology , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Environment , Family Health , Female , Humans , Immunoglobulin Heavy Chains/genetics , Male , Mutation , PhenotypeABSTRACT
Our understanding of the genetic basis of chronic lymphocytic leukemia is only just starting to be recognized. This perspective article by Drs. Crowther-Swanepoel and Houlston provides an up-to-date review the molecular epidemiology of chronic lymphocytic leukemia, with emphasis on the integration of biology and genomics.
Subject(s)
Family Health , Family , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Genetic Heterogeneity , Genetic Predisposition to Disease/genetics , Humans , Lymphoma, Non-Hodgkin/genetics , Polymorphism, Single NucleotideABSTRACT
To identify new risk variants for chronic lymphocytic leukemia (CLL), we conducted a genome-wide association study of 299,983 tagging SNPs, with validation in four additional series totaling 2,503 cases and 5,789 controls. We identified four new risk loci for CLL at 2q37.3 (rs757978, FARP2; odds ratio (OR) = 1.39; P = 2.11 x 10(-9)), 8q24.21 (rs2456449; OR = 1.26; P = 7.84 x 10(-10)), 15q21.3 (rs7169431; OR = 1.36; P = 4.74 x 10(-7)) and 16q24.1 (rs305061; OR = 1.22; P = 3.60 x 10(-7)). We also found evidence for risk loci at 15q25.2 (rs783540, CPEB1; OR = 1.18; P = 3.67 x 10(-6)) and 18q21.1 (rs1036935; OR = 1.22; P = 2.28 x 10(-6)). These data provide further evidence for genetic susceptibility to this B-cell hematological malignancy.
Subject(s)
Chromosomes, Human/genetics , Genetic Predisposition to Disease , Genetic Variation , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Alleles , Genetic Loci/genetics , Genome, Human/genetics , Humans , Polymorphism, Single Nucleotide/geneticsABSTRACT
We conducted a genome-wide association study of 299,983 tagging SNPs for chronic lymphocytic leukemia (CLL) and performed validation in two additional series totaling 1,529 cases and 3,115 controls. We identified six previously unreported CLL risk loci at 2q13 (rs17483466; P = 2.36 x 10(-10)), 2q37.1 (rs13397985, SP140; P = 5.40 x 10(-10)), 6p25.3 (rs872071, IRF4; P = 1.91 x 10(-20)), 11q24.1 (rs735665; P = 3.78 x 10(-12)), 15q23 (rs7176508; P = 4.54 x 10(-12)) and 19q13.32 (rs11083846, PRKD2; P = 3.96 x 10(-9)). These data provide the first evidence for the existence of common, low-penetrance susceptibility to a hematological malignancy and new insights into disease causation in CLL.