title: Functional and Structural Impact of ATP-Binding Cassette Transporter A1 R219K and I883M Gene Polymorphisms in Obese Children and Adolescents.
abstract: BACKGROUND
  Obesity is a serious medical condition that affects children and adolescents. ATP-binding cassette transporter A1 (ABCA1) protein is known to mediate the transport of intracellular cholesterol and phospholipids across the cell membranes. Thus, we aimed to investigate the association between ABCA1 gene polymorphisms and overweight/obesity risk, and to evaluate their relation to the lipid profile.
  
  
  METHODS
  The study included in silico analysis of ABCA1 gene and protein. Two genetic variants in ABCA1 gene-R219K (rs2230806; G/A) and I883M (rs2066714; A/G)-were genotyped in 128 normal weight and 128 overweight/obese subjects using polymerase chain reaction-restriction fragment length polymorphism technology. Anthropometric and biochemical assessments were performed.
  
  
  RESULTS
  Our findings suggest that the heterozygote GA genotype of R219K polymorphism increased susceptibility to obesity under the heterozygous model (odds ratio 2.75, 95 % CI 1.01-6.12; p = 0.014) compared with the control group. This susceptibility could be gender-specific, with higher risk among females. In addition, the A variant was associated with a higher degree of obesity (p < 0.001). On the other hand, individuals with the G variant of I883M polymorphism showed lower susceptibility to obesity under all genetic models (allelic, homozygote, heterozygote, dominant, and recessive models; p < 0.05), with no observed association with body mass index or degree of obesity. However, both single nucleotide polymorphisms (SNPs) showed significant differences in lipid levels among patients with different genotypes.
  
  
  CONCLUSIONS
  The study results suggest that R219K and I883M SNPs of the ABCA1 gene may play a role in susceptibility to obesity in our Egyptian population; the former increases susceptibility and phenotype severity, and the latter is protective. Larger epidemiological studies are needed for validation of the results.
authors.affiliation: Department of Medical Biochemistry, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, manal2_khashana@ymail.com.
authors.forename: Manal S
authors.initials: MS
authors.lastname: Fawzy
authors.forename: Osama
authors.initials: O
authors.lastname: Alhadramy
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Hussein
authors.forename: Hussein M
authors.initials: HM
authors.lastname: Ismail
authors.forename: Nesreen M
authors.initials: NM
authors.lastname: Ismail
authors.forename: Nouran M
authors.initials: NM
authors.lastname: Biomy
authors.forename: Eman A
authors.initials: EA
authors.lastname: Toraih
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000737:chemistry* / Q000235:genetics*; D000293:Adolescent; D000886:Anthropometry; D001483:Base Sequence; D001692:Biological Transport; D002648:Child; D002784:Cholesterol / Q000378:metabolism; D003198:Computer Simulation; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009765:Obesity / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D002784:Cholesterol