title: Association of the rs738409 polymorphism in PNPLA3 with liver damage and the development of nonalcoholic fatty liver disease.
abstract: BACKGROUND
  In a genome-wide association scan, the single-nucleotide polymorphism (SNP) rs738409 in the patatin-like phospholipase 3 gene (PNPLA3) was strongly associated with increased liver fat content. We investigated whether this SNP is associated with the occurrence and progression of nonalcoholic fatty liver disease (NAFLD) in the Japanese population.
  
  
  METHODS
  SNP rs738409 was genotyped by the Taqman assay in 253 patients with NAFLD (189 with nonalcoholic steatohepatitis [NASH] and 64 with simple steatosis) and 578 control subjects. All patients with NAFLD underwent liver biopsy. Control subjects had no metabolic disorders. For a case-control study, the χ(2)-test (additive model) was performed. Odds ratios (ORs) were adjusted for age, gender, and body mass index (BMI) by using multiple logistic regression analysis with genotypes (additive model), age, gender, and BMI as the independent variables. Multiple linear regression analysis was performed to test the independent effect of risk allele on clinical parameters while considering the effects of other variables (age, gender, and BMI), which were assumed to be independent of the effect of the SNP.
  
  
  RESULTS
  The risk allele (G-allele) frequency of rs738409 was 0.44 in the control subjects and 0.60 in patients with NAFLD; this shows a strong association with NAFLD (additive model, P = 9.4 x 10(-10)). The OR (95% confidence interval) adjusted for age, gender, and BMI was 1.73 (1.25-2.38). Multiple linear regression analysis indicated that the G-allele of rs738409 was significantly associated with increases in aspartate transaminase (AST) (P = 0.00013), alanine transaminase (ALT) (P = 9.1 x 10(-6)), and ferritin levels (P = 0.014), and the fibrosis stage (P = 0.011) in the patients with NAFLD, even after adjustment for age, gender, and BMI. The steatosis grade was not associated with rs738409.
  
  
  CONCLUSIONS
  We found that in the Japanese population, individuals harboring the G-allele of rs738409 were susceptible to NAFLD, and that rs738409 was associated with plasma levels of ALT, AST, and ferritin, and the histological fibrosis stage. Our study suggests that PNPLA3 may be involved in the progression of fibrosis in NAFLD.
authors.affiliation: EBM Research Center, Kyoto University Graduate School of Medicine, Japan. kikukoh@kuhp.kyoto-u.ac.jp
authors.forename: Kikuko
authors.initials: K
authors.lastname: Hotta
authors.forename: Masato
authors.initials: M
authors.lastname: Yoneda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hyogo
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ochi
authors.forename: Seiho
authors.initials: S
authors.lastname: Mizusawa
authors.forename: Takato
authors.initials: T
authors.lastname: Ueno
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakajima
authors.forename: Kazuwa
authors.initials: K
authors.lastname: Nakao
authors.forename: Akhiro
authors.initials: A
authors.lastname: Sekine
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000483:Alleles; D001219:Aspartate Aminotransferases / Q000097:blood; D015992:Body Mass Index; D016022:Case-Control Studies; D005234:Fatty Liver / Q000235:genetics* / Q000473:pathology; D005260:Female; D005293:Ferritins / Q000097:blood; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008049:Lipase / Q000235:genetics*; D008103:Liver Cirrhosis / Q000473:pathology; D008107:Liver Diseases / Q000235:genetics* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D016017:Odds Ratio; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012737:Sex Factors; D000217:Acyltransferases; D054512:Phospholipases A2, Calcium-Independent
chemical_list: D000410:Alanine Transaminase; D001219:Aspartate Aminotransferases; D005293:Ferritins; D008049:Lipase; D008565:Membrane Proteins; C533682:PNPLA3 protein, human; D000217:Acyltransferases; D054512:Phospholipases A2, Calcium-Independent