title: Genetic variant I148M in PNPLA3 is associated with the ultrasonography-determined steatosis degree in a Chinese population.
abstract: BACKGROUND
  Nonalcoholic fatty liver disease (NAFLD) is an escalating medical problem worldwide. A nonsynonymous single nucleotide polymorphism rs738409 (I148M) in patatin-like phospholipase domain-containing protein 3 (PNPLA3) predisposes susceptibility to NAFLD; however, its association with steatosis grade is inconsistent in the literature. In particular, there was no significant association found between I148M and steatosis grade in two East Asian-based studies. In this study we aim to investigate whether I148M is associated with the ultrasonography-determined steatosis degree in Chinese adults.
  
  
  METHODS
  203 NAFLD cases and 202 matched controls were recruited. Cases were classified into mild, moderate and severe fatty liver by ultrasonography. Association between I148M and the ultrasonography-determined steatosis degree as well as other clinical parameters was evaluated.
  
  
  RESULTS
  The I148M variant was associated with the ultrasonography-determined steatosis degree with the M allele frequencies being 0.32, 0.54, and 0.87 in mild (n=105), moderate (n=83), and severe (n=15) cases, respectively (P-value = 7.6 × 10(-8)). We also confirmed the interaction between I148M variation and body mass index towards elevated plasma alanine aminotransferase levels in cases (P-value = 4.4 × 10(-4)).
  
  
  CONCLUSIONS
  The PNPLA3 I148M variant is associated with the ultrasonography-determined steatosis degree in Chinese population.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, China. lyl72@hotmail.com
authors.forename: Yiling
authors.initials: Y
authors.lastname: Li
authors.forename: Chao
authors.initials: C
authors.lastname: Xing
authors.forename: Zhong
authors.initials: Z
authors.lastname: Tian
authors.forename: Hung-Chih
authors.initials: HC
authors.lastname: Ku
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008049:Lipase / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D020641:Polymorphism, Single Nucleotide; D014463:Ultrasonography; D000217:Acyltransferases; D054512:Phospholipases A2, Calcium-Independent
chemical_list: D008049:Lipase; D008565:Membrane Proteins; C533682:PNPLA3 protein, human; D000217:Acyltransferases; D054512:Phospholipases A2, Calcium-Independent