title: Contribution of Toll-Like Receptor 9 Gene Single-Nucleotide Polymorphism to Systemic Lupus Erythematosus in Egyptian Patients.
abstract: BACKGROUND
  Systemic lupus erythematosus (SLE) is an autoimmune disease, with multiple genetic and environmental factors involved in its etiology. The toll-like receptor 9 (TLR9) gene has been reported to have important roles in the development and progression of SLE. In this case-control study, the effect of TLR9 polymorphism on susceptibility to SLE was investigated in Egyptian patients.
  
  
  METHODS
  We studied the distribution of the TLR9 rs352139 (G + 1174A) single nucleotide polymorphism (SNP) by allele-specific polymerase chain reaction (PCR) in 104 Egyptian patients with SLE and 108 age-, sex-, and ethnically matched controls.
  
  
  RESULTS
  There was no statistically significant difference in the distribution of the AA genotype and alleles between SLE patients and the control group in our study; however, the GA heterozygous patients were three times more likely to develop SLE (P < 0.001). A significant association was detected between TLR9 genotypes and some of the disease manifestations as myositis (p = 0.032), psychosis (p = 0.014), photosensitivity (p = 0.002), and pleurisy (p = <0.001). Moreover, we observed a significant association between the TLR9 AA and GA genotypes and the presence of antinuclear antibodies (ANA) (p = 0.038).
  
  
  CONCLUSIONS
  The G + 1174A SNP in the toll receptor 9 gene may contribute to the genetic susceptibility of SLE in Egyptian patients. Also, an influence for this polymorphism on disease manifestations has been elucidated.
authors.affiliation: a Department of Clinical Pathology , Kasr Al Ainy Hospital, Cairo University , Cairo , Egypt.
authors.forename: Rasha Mohamad Hosny
authors.initials: RM
authors.lastname: Shahin
authors.affiliation: a Department of Clinical Pathology , Kasr Al Ainy Hospital, Cairo University , Cairo , Egypt.
authors.forename: Engy
authors.initials: E
authors.lastname: El Khateeb
authors.affiliation: a Department of Clinical Pathology , Kasr Al Ainy Hospital, Cairo University , Cairo , Egypt.
authors.forename: Rania Hassan
authors.initials: RH
authors.lastname: Khalifa
authors.affiliation: b Department of Rheumatology and Rehabilitation , Kasr Al Ainy Hospital, Cairo University , Cairo , Egypt.
authors.forename: Rasha Mahmoud
authors.initials: RM
authors.lastname: El Refai
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D004534:Egypt; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000235:genetics*; D016017:Odds Ratio; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D051217:Toll-Like Receptor 9 / Q000235:genetics*; D055815:Young Adult
chemical_list: D051217:Toll-Like Receptor 9
keywords: Polymorphis; TLR9; systemic lupus erythematosus