BACKGROUNDThere is considerable variation in disease behavior among patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 . Genomewide association analysis may allow for the identification of potential genetic factors involved in the development of Covid-19. METHODSWe conducted a genomewide association study involving 1980 patients with Covid-19 and severe disease (defined as respiratory failure) at seven hospitals in the Italian and Spanish epicenters of the SARS-CoV-2 pandemic in Europe. After quality control and the exclusion of population outliers, 835 patients and 1255 control participants from Italy and 775 patients and 950 control participants from Spain were included in the final analysis. In total, we analyzed 8,582,968 single-nucleotide polymorphisms and conducted a meta-analysis of the two case-control panels. RESULTSWe detected cross-replicating associations with rs11385942 at locus 3p21.31 and with rs657152 at locus 9q34.2, which were significant at the genomewide level (P<5×10 −8 ) in the meta-analysis of the two case-control panels (odds ratio, 1.77; 95% confidence interval [CI], 1.48 to 2.11; P = 1.15×10 −10 ; and odds ratio, 1.32; 95% CI, 1.20 to 1.47; P = 4.95×10 −8 , respectively). At locus 3p21.31, the association signal spanned the genes SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6 and XCR1. The association signal at locus 9q34.2 coincided with the ABO blood group locus; in this cohort, a blood-group-specific analysis showed a higher risk in blood group A than in other blood groups (odds ratio, 1.45; 95% CI, 1.20 to 1.75; P = 1.48×10 −4 ) and a protective effect in blood group O as compared with other blood groups (odds ratio, 0.65; 95% CI, 0.53 to 0.79; P = 1.06×10 −5 ). CONCLUSIONSWe identified a 3p21.31 gene cluster as a genetic susceptibility locus in patients with Covid-19 with respiratory failure and confirmed a potential involvement of the ABO blood-group system. (Funded by Stein Erik Hagen and others.

Inherited factors play a major role in the predisposition to nonalcoholic fatty liver disease (NAFLD), and the rs738409 CfiG polymorphism of PNPLA3/adiponutrin, encoding for the isoleucine-to-methionine substitution at residue 148 (I148M) protein variant, has recently been recognized as a major determinant of liver fat content. However, the effect of the rs738409 polymorphism on the severity of liver fibrosis in patients with NAFLD is still unknown. In this study, we considered 253 Italian patients, 179 healthy controls, and 71 family trios with an affected child with NAFLD. Analyses were replicated in 321 patients from the United Kingdom. The rs738409 polymorphism was determined by TaqMan assays. Liver histology was scored according to Kleiner et al. Hepatic expression of genes regulating liver damage was assessed by real-time polymerase chain reaction in 52 patients. The rs738409 GG genotype was more prevalent in patients than in controls (14% versus 3%, adjusted odds ratio [OR] 5 3.29, 95% confidence interval [CI] 5 1.8-6.9), and in the family study, the G allele was overtransmitted to affected children (P 5 0.001). In Italian and United Kingdom patients, adiponutrin genotype influenced alanine aminotransferase levels and the severity of steatosis. Adiponutrin genotype was associated with the expression of genes involved in the steatosis-related liver damage, including the proapoptotic molecule Fas ligand. In the whole series combined, adiponutrin genotype was associated with steatosis grade >1 (OR 5 1.35, 95% CI 5 1.04-1.76), nonalcoholic steatohepatitis (OR 5 1.5, 95% CI 5 1.12-2.04), and fibrosis stage >1 (OR 5 1.5, 95% CI 5 1.09-2.12), independent of age, body mass index, and diabetes. Adiponutrin genotype demonstrated a dose effect with heterozygote risk intermediate between CC and GG homozygotes. Conclusion: In patients with NAFLD, adiponutrin rs738409 CfiG genotype, encoding for I148M, is associated with the severity of steatosis and fibrosis and the presence of nonalcoholic steatohepatitis. (HEPATOLOGY 2010;51:1209-1217 Abbreviations: ALT, alanine aminotransferase; FASL, Fas ligand; FFA, free fatty acid; HDL, high-density lipoprotein; INSR, insulin receptor; LDL, low-density lipoprotein; mRNA, messenger RNA; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; PNPLA3, patatin-like phospholipase-3; PPARa, peroxisome proliferator-activated receptor-a; qRT-PCR, quantitative real-time polymerase chain reaction; a-SMA, a-smooth muscle actin; SNP, single-nucleotide polymorphism; SREBP1c, steroid regulatory element binding protein 1c.From the

invasive stratification of hepatocellular carcinoma risk in non-alcoholic fatty liver using polygenic risk scores,

Nonalcoholic fatty liver disease (NAFLD) represents an emerging cause of hepatocellular carcinoma (HCC), especially in non-cirrhotic individuals. The rs641738 C > T MBOAT7/TMC4 variant predisposes to progressive NAFLD, but the impact on hepatic carcinogenesis is unknown. In Italian NAFLD patients, the rs641738 T allele was associated with NAFLD-HCC (OR 1.65, 1.08–2.55; n = 765), particularly in those without advanced fibrosis (p < 0.001). The risk T allele was linked to 3’-UTR variation in MBOAT7 and to reduced MBOAT7 expression in patients without severe fibrosis. The number of PNPLA3, TM6SF2, and MBOAT7 risk variants was associated with NAFLD-HCC independently of clinical factors (p < 0.001), but did not significantly improve their predictive accuracy. When combining data from an independent UK NAFLD cohort, in the overall cohort of non-cirrhotic patients (n = 913, 41 with HCC) the T allele remained associated with HCC (OR 2.10, 1.33–3.31). Finally, in a combined cohort of non-cirrhotic patients with chronic hepatitis C or alcoholic liver disease (n = 1121), the T allele was independently associated with HCC risk (OR 1.93, 1.07–3.58). In conclusion, the MBOAT7 rs641738 T allele is associated with reduced MBOAT7 expression and may predispose to HCC in patients without cirrhosis, suggesting it should be evaluated in future prospective studies aimed at stratifying NAFLD-HCC risk.