Most genetic variants associated with complex traits are hypothesized to regulate gene expression. To understand the genetics underlying gene expression variability, we characterized 14,324 RNA-sequencing samples from the Trans-Omics for Precision Medicine program and performed expression and splicing quantitative trait locus (e/sQTL) analyses in six tissues and cell types, including whole blood ( n = 6454) and lung ( n = 1291). We detected tens of thousands of secondary cis-e/sQTLs, showing that secondary cis-e/sQTL discovery remains unsaturated. We fine-mapped UK Biobank–derived genome-wide association study (GWAS) signals from 164 traits and identified e/sQTL colocalizations for 10,611 GWAS signals, including 7096 that colocalize with secondary e/sQTLs. Our results suggest that even larger e/sQTL analyses will uncover additional secondary e/sQTLs, further benefiting GWAS interpretation.
A large-scale multi-ethnic genome-wide association study of coronary artery disease
Abstract Coronary artery disease (CAD) is a leading cause of death, yet its genetic determinants are not fully elucidated. We report a multi-ethnic genome-wide association study of CAD involving nearly a quarter of a million cases, incorporating the largest cohorts to date of Whites, Blacks, and Hispanics from the Million Veteran Program with existing studies including CARDIoGRAMplusC4D, UK Biobank, and Biobank Japan. We verify substantial and nearly equivalent heritability of CAD across multiple ancestral groups, discover 107 novel loci including the first nine on the X-chromosome, identify the first eight genome-wide significant loci among Blacks and Hispanics, and demonstrate that two common haplotypes are largely responsible for the risk stratification at the well-known 9p21 locus in most populations except those of African origin where both haplotypes are virtually absent. We identify 15 loci for angiographically derived burden of coronary atherosclerosis, which robustly overlap with the strongest and earliest loci reported to date for clinical CAD. Phenome-wide association analyses of novel loci and externally validated polygenic risk scores (PRS) augment signals from the insulin resistance cluster of risk factors and consequences, extend previously established pleiotropic associations of loci with traditional risk factors to include smoking and family history, and confirm a substantially reduced transferability of existing PRS to Blacks. Downstream integrative genomic analyses reinforce the critical role of endothelial, fibroblast, and smooth muscle cells within the coronary vessel wall in CAD susceptibility. Our study highlights the value of a multi-ethnic design in efficiently characterizing the genetic architecture of CAD across all human populations.
Anti-inflammatory Efficacy of Combined Natural Alkaloid Berberine and S1PR Modulator Fingolimod at Low Doses in Ulcerative Colitis Preclinical Models
Background and Aims Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with a relapsing–remitting pattern that belongs to autoimmune disease (AID). The JAK inhibitor tofacitinib is a newly (2018.05) FDA approved drug for UC which is a drug previously used to treat another AID, rheumatoid arthritis. A higher dose of tofacitinib has been associated with a safety warning for increased lipid levels as well as serious infections and malignancy. Berberine has proved to be a promising drug candidate for the treatment of UC and shows activity in hyperlipidemia, bacteria; infections and cancer. We hypothesized that a balance between clinical benefit and side effects might be attained by using a combination of tofacitinib and berberine‐‐with reduced doses of both drugs. We first investigated the preclinical activity of reduced doses of tofacitinib plus berberine in experimental colitis in the mouse. Methods Tofacitinib (30 mg/kg/day), berberine (40 mg/kg/day) and reduced doses of tofacitinib (15 mg/kg/day) plus berberine (20 mg/kg/day) were administered orally for 14 and 30 days to C57BL/6 mice with colitis induced by two schedules of three cycles of 2% dextran sulfate sodium (DSS). Disease severity, colon length, colon and spleen swelling and cytokine expression in colon tissue as well as histology of major organs were examined. Results The results showed that compared to the two drugs alone, half reduced doses of tofacitinib plus berberine showed a comparable effect in ameliorating DSS‐induced colitis severity and colon shortening. Co‐treatment showed a greater antagonism of DSS induced colon and spleen swelling when compared to either drug alone. Similar effects were observed in cytokine levels in the colon. In addition, no potential toxicity to major organs was observed with this combination therapy. Conclusions Our studies provide a preclinical rationale for the combination of reduced dosage tofacitinib and berberine as a possible clinical therapeutic strategy for the treatment of UC. Support or Funding Information This work was funded by the Research Foundation of South China University of Technology (x2yxD2182200), the Natural Science Foundation of Guangdong Province (2018A030310388), Guangdong Medical Science Foundation (A2018363), and China Scholarship Council (Grant No. CSC201806155103).
Universal screening for Lynch syndrome in a large consecutive cohort of Chinese colorectal cancer patients: High prevalence and unique molecular features
The prevalence of Lynch syndrome (LS) varies significantly in different populations, suggesting that ethnic features might play an important role. We enrolled 3330 consecutive Chinese patients who had surgical resection for newly diagnosed colorectal cancer. Universal screening for LS was implemented, including immunohistochemistry for mismatch repair (MMR) proteins, BRAFV600E mutation test and germline sequencing. Among the 3250 eligible patients, MMR protein deficiency (dMMR) was detected in 330 (10.2%) patients. Ninety‐three patients (2.9%) were diagnosed with LS. Nine (9.7%) patients with LS fulfilled Amsterdam criteria II and 76 (81.7%) met the revised Bethesda guidelines. Only 15 (9.7%) patients with absence of MLH1 on IHC had BRAFV600E mutation. One third (33/99) of the MMR gene mutations have not been reported previously. The age of onset indicates risk of LS in patients with dMMR tumors. For patients older than 65 years, only 2 patients (5.7%) fulfilling revised Bethesda guidelines were diagnosed with LS. Selective sequencing of all cases with dMMR diagnosed at or below age 65 years and only of those dMMR cases older than 65 years who fulfill revised Bethesda guidelines results in 8.2% fewer cases requiring germline testing without missing any LS diagnoses. While the prevalence of LS in Chinese patients is similar to that of Western populations, the spectrum of constitutional mutations and frequency of BRAFV600E mutation is different. Patients older than 65 years who do not meet the revised Bethesda guidelines have a low risk of LS, suggesting germline sequencing might not be necessary in this population.