@article {133, title = {Association of Genetic Variation With Cirrhosis: A Multi-Trait Genome-Wide Association and Gene-Environment Interaction Study.}, journal = {Gastroenterology}, volume = {160}, year = {2021}, month = {2021 Apr}, pages = {1620-1633.e13}, abstract = {

BACKGROUND \& AIMS: In contrast to most other common diseases, few genetic variants have been identified that impact risk of cirrhosis. We aimed to identify new genetic variants that predispose to cirrhosis, to test whether such variants, aggregated into a polygenic score, enable genomic risk stratification, and to test whether alcohol intake or body mass index interacts with polygenic predisposition.

METHODS: We conducted a multi-trait genome-wide association study combining cirrhosis and alanine aminotransferase levels performed in 5 discovery studies (UK Biobank, Vanderbilt BioVU, Atherosclerosis Risk in Communities study, and 2 case-control studies including 4829 individuals with cirrhosis and 72,705 controls and 362,539 individuals with alanine aminotransferase levels). Identified variants were replicated in 3 studies (Partners HealthCare Biobank, FinnGen, and Biobank Japan including 3554 individuals with cirrhosis and 343,826 controls). A polygenic score was tested in Partners HealthCare Biobank.

RESULTS: Five previously reported and 7 newly identified genetic variants were associated with cirrhosis in both the discovery studies multi-trait genome-wide association study (P < 5~{\texttimes} 10) and the replication studies (P < .05), including a missense variant in the APOE gene and a noncoding variant near EFN1A. These 12 variants were used to generate a polygenic score. Among Partners HealthCare Biobank individuals, high polygenic score-defined as the top quintile of the distribution-was associated with significantly increased risk of cirrhosis (odds ratio, 2.26; P < .001) and related comorbidities compared with the lowest quintile. Risk was even more pronounced among those with extreme polygenic risk (top 1\% of the distribution, odds ratio, 3.16; P < .001). The impact of extreme polygenic risk was substantially more pronounced in those with elevated alcohol consumption or body mass index. Modeled as risk by age 75 years, probability of cirrhosis with extreme polygenic risk was 13.7\%, 20.1\%, and 48.2\% among individuals with no or modest, moderate, and increased alcohol consumption, respectively (P < .001). Similarly, probability among those with extreme polygenic risk was 6.5\%, 10.3\%, and 19.5\% among individuals with normal weight, overweight, and obesity, respectively (P < .001).

CONCLUSIONS: Twelve independent genetic variants, 7 of which are newly identified in this study, conferred risk for cirrhosis. Aggregated into a polygenic score, these variants identified a subset of the population at substantially increased risk who are most susceptible to the hepatotoxic effects of excess alcohol consumption or obesity.

}, issn = {1528-0012}, doi = {10.1053/j.gastro.2020.12.011}, author = {Emdin, Connor A and Haas, Mary and Ajmera, Veeral and Simon, Tracey G and Homburger, Julian and Neben, Cynthia and Jiang, Lan and Wei, Wei-Qi and Feng, Qiping and Zhou, Alicia and Denny, Joshua and Corey, Kathleen and Loomba, Rohit and Kathiresan, Sekar and Khera, Amit V} } @article {131, title = {A missense variant in Mitochondrial Amidoxime Reducing Component 1 gene and protection against liver disease.}, journal = {PLoS Genet}, volume = {16}, year = {2020}, month = {2020 04}, pages = {e1008629}, abstract = {

Analyzing 12,361 all-cause cirrhosis cases and 790,095 controls from eight cohorts, we identify a common missense variant in the Mitochondrial Amidoxime Reducing Component 1 gene (MARC1 p.A165T) that associates with protection from all-cause cirrhosis (OR 0.91, p = 2.3*10-11). This same variant also associates with lower levels of hepatic fat on computed tomographic imaging and lower odds of physician-diagnosed fatty liver as well as lower blood levels of alanine transaminase (-0.025 SD, 3.7*10-43), alkaline phosphatase (-0.025 SD, 1.2*10-37), total cholesterol (-0.030 SD, p = 1.9*10-36) and LDL cholesterol (-0.027 SD, p = 5.1*10-30) levels. We identified a series of additional MARC1 alleles (low-frequency missense p.M187K and rare protein-truncating p.R200Ter) that also associated with lower cholesterol levels, liver enzyme levels and reduced risk of cirrhosis (0 cirrhosis cases for 238 R200Ter carriers versus 17,046 cases of cirrhosis among 759,027 non-carriers, p = 0.04) suggesting that deficiency of the MARC1 enzyme may lower blood cholesterol levels and protect against cirrhosis.

}, keywords = {Alleles, Cholesterol, LDL, Coronary Artery Disease, Datasets as Topic, Fatty Liver, Female, Genetic Predisposition to Disease, Homozygote, Humans, Liver, Liver Cirrhosis, Liver Cirrhosis, Alcoholic, Loss of Function Mutation, Male, Middle Aged, Mitochondrial Proteins, Mutation, Missense, Oxidoreductases}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1008629}, author = {Emdin, Connor A and Haas, Mary E and Khera, Amit V and Aragam, Krishna and Chaffin, Mark and Klarin, Derek and Hindy, George and Jiang, Lan and Wei, Wei-Qi and Feng, Qiping and Karjalainen, Juha and Havulinna, Aki and Kiiskinen, Tuomo and Bick, Alexander and Ardissino, Diego and Wilson, James G and Schunkert, Heribert and McPherson, Ruth and Watkins, Hugh and Elosua, Roberto and Bown, Matthew J and Samani, Nilesh J and Baber, Usman and Erdmann, Jeanette and Gupta, Namrata and Danesh, John and Saleheen, Danish and Chang, Kyong-Mi and Vujkovic, Marijana and Voight, Ben and Damrauer, Scott and Lynch, Julie and Kaplan, David and Serper, Marina and Tsao, Philip and Mercader, Josep and Hanis, Craig and Daly, Mark and Denny, Joshua and Gabriel, Stacey and Kathiresan, Sekar} }