Much of the variation in inherited risk of colorectal cancer (CRC) is probably due to combinations of common low risk variants. We conducted a genome-wide association study of 550,000 tag SNPs in 930 familial colorectal tumor cases and 960 controls. The most strongly associated SNP (P = 1.72 x 10(-7), allelic test) was rs6983267 at 8q24.21. To validate this finding, we genotyped rs6983267 in three additional CRC case-control series (4,361 affected individuals and 3,752 controls; 1,901 affected individuals and 1,079 controls; 1,072 affected individuals and 415 controls) and replicated the association, providing P = 1.27 x 10(-14) (allelic test) overall, with odds ratios (ORs) of 1.27 (95% confidence interval (c.i.): 1.16-1.39) and 1.47 (95% c.i.: 1.34-1.62) for heterozygotes and rare homozygotes, respectively. Analyses based on 1,477 individuals with colorectal adenoma and 2,136 controls suggest that susceptibility to CRC is mediated through development of adenomas (OR = 1.21, 95% c.i.: 1.10-1.34; P = 6.89 x 10(-5)). These data show that common, low-penetrance susceptibility alleles predispose to colorectal neoplasia.

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.

Chronic lymphocytic leukemia (CLL) and other B-cell lymphoproliferative disorders display familial aggregation. To identify a susceptibility gene for CLL, we assembled families from the major European (ICLLC) and American (GEC) consortia to conduct a genome-wide linkage analysis of 101 new CLL pedigrees using a high-density single nucleotide polymorphism (SNP) array and combined the results with data from our previously reported analysis of 105 families. Here, we report on the combined analysis of the 206 families. Multipoint linkage analyses were undertaken using both nonparametric (model-free) and parametric (modelbased) methods. After the removal of high linkage disequilibrium SNPs, we obtained a maximum nonparametric linkage (NPL) score of 3.02 (P ‫؍‬ .001) on chromosome 2q21.2. The same genomic position also yielded the highest multipoint heterogeneity LOD (HLOD) score under a common recessive model of disease susceptibility (HLOD ‫؍‬ 3.11; P ‫؍‬ 7.7 ؋ 10 ؊5 ), which was significant at the genome-wide level. In addition, 2 other chromosomal positions, 6p22.1 (corresponding to the major histocompatibility locus) and 18q21.1, displayed HLOD scores higher than 2.1 (P < The striking multiple-case families reported in the literature provide substantive evidence for an inherited predisposition to CLL 2-4 and suggest the existence of susceptibility alleles with pleiotropic effects. 2,10 Case-control and cohort studies that have systematically estimated the familial risk of CLL and other LPDs have shown that most B-cell LPDs display site-specific elevated familial risks, 5-9 but particularly CLL, where risks are increased 3-to 7-fold in first-degree relatives of cases. Furthermore, such studies have demonstrated that familial associations exist between the different types of B-cell LPDs with risks of NHL and HL showing 2-fold increases in relatives of CLL cases..These observations provide a strong rationale for searching for predisposition genes for CLL through linkage searches of multiplecase families. Two genome-wide linkage scans have been conducted to date. The first reported by Goldin et al 11 in 2003 used 359 microsatellite markers to genotype 18 CLL families. In 2005, a second genome-wide scan of 105 families segregating CLL with or without additional B-cell LPD cases was conducted using the Affymetrix Mapping 10Kv131 array, which contained approximately 11 500 single nucleotide polymorphisms (SNPs). 12 In both studies, analyses provided evidence for susceptibility at a number of loci, but none achieved statistical significance, suggesting that a much larger familial sample was required to identify CLL predisposition loci.To address this, we have undertaken a further genome-wide linkage scan of an additional 101 families ascertained through the International CLL Consortium (ICLLC) and the Genetic Epidemiology of CLL (GEC) consortia. This search was conducted using high-density SNP arrays, thereby allowing us to pool findings with data generated from our previous scan of 105 families and in so An Inside Blood...

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We report on four siblings with Cockayne-like syndrome with thrombocytopenia and nephrotic syndrome. The parents were healthy and consanguineous, consistent with an autosomal recessive mode of disease inheritance. UV irradiation of fibroblasts revealed an intermediate sensitivity between normal and standard Cockayne syndrome (CS) control cells. A genome-wide linkage scan conducted using Affymetrix 10K arrays provided exclusion of the known CS genes in the family, and evidence that the disease gene maps to 1p33-p31.1. Thrombocytopenia has not previously been linked with CS, but two patients with CS in association with nephrotic syndrome have previously been documented and the phenotypes are compared with the patients described here. We suggest that this Cockayne-like phenotype with thrombocytopenia and nephrotic syndrome may be a novel DNA repair disorder, and propose that further investigation of other affected families may help identify the causative genetic defect.