ENIGMA
CHEK2
gether Project: A Comprehensive Study Identifies Functionally Impaired
CHEK2
Germline Missense Variants Associated with Increased Breast Cancer Risk
Abstract Purpose: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT). Experimental Design: We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1–CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case–control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls. Results: A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)–like (N = 226). We then examined their association with breast cancer risk in the case–control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35–3.41), 1.57 (95% CI, 1.41–1.75), and 1.19 (95% CI, 1.08–1.31), respectively. The meta-analysis of population-specific datasets showed similar results. Conclusions: We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers.
Genetic Variants Associated With Uncontrolled Blood Pressure on Thiazide Diuretic/β‐Blocker Combination Therapy in the PEAR (Pharmacogenomic Evaluation of Antihypertensive Responses) and INVEST (International Verapamil‐SR Trandolapril Study) Trials
Background The majority of hypertensive individuals require combination antihypertensive therapy to achieve adequate blood pressure ( BP ) control. This study aimed to identify genetic variants associated with uncontrolled BP on combination therapy with a thiazide diuretic and a β‐blocker. Methods and Results A genome‐wide association study of uncontrolled BP on combination therapy was conducted among 314 white participants of the PEAR (Pharmacogenomic Evaluation of Antihypertensive Responses) trial. Multivariable logistic regression analysis was used. Genetic variants meeting a suggestive level of significance ( P <1.0E‐05) were tested for replication in an external cohort, INVEST (International Verapamil‐ SR Trandolapril study). We also examined genome‐wide variant associations with systolic and diastolic BP response on combination therapy and tested for replication. We discovered a single nucleotide polymorphism, the rs261316 major allele, at chromosome 15 in the gene ALDH1A2 associated with an increased odds of having uncontrolled BP on combination therapy (odds ratio: 2.56, 95% confidence interval, 1.69–3.88, P =8.64E‐06). This single nucleotide polymorphism replicated (odds ratio: 1.86, 95% confidence interval, 1.35–2.57, P =0.001) and approached genome‐wide significance in the meta‐analysis between discovery and replication cohorts (odds ratio: 2.16, 95% confidence interval, 1.63–2.86, P =8.60E‐08). Other genes in the region surrounding rs261316 ( ALDH1A2) include AQP9 and LIPC . Conclusions A single nucleotide polymorphism in the gene ALDH1A2 may be associated with uncontrolled BP following treatment with a thiazide diuretic/β‐blocker combination. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT 00246519.