title: An investigation into LOXL1 variants in black South African individuals with exfoliation syndrome.
abstract: OBJECTIVE
  To investigate the association between 2 lysyl oxidase-like 1 (LOXL1) polymorphisms, rs1048661 (R141L) and rs3825942 (G153D), and exfoliation syndrome (XFS) in black South African individuals.
  
  
  METHODS
  A total of 43 black patients with XFS and 47 ethnically matched controls were recruited for genetic analysis. Samples were analyzed for presence of the LOXL1-R141L and G153D variants using restriction fragment length polymorphism analysis. A case-control association study was performed.
  
  
  RESULTS
  The R141L and G153D single-nucleotide polymorphisms (SNPs) were both significantly associated with XFS (P = .00582 and P < .00001, respectively). Consistent with findings in white populations but not in Asian cohorts, the GG genotype of the R141L SNP was present in significantly more XFS cases than controls (P = .00582). However, in this black South African study population, the AA genotype of G153D was present in an overwhelming majority of cases with XFS (P < .00001; odds ratio, 17.10; 95% confidence interval, 4.91-59.56), contrary to all previous articles in which the GG genotype was strongly associated with the disease phenotype.
  
  
  CONCLUSIONS
  The LOXL1 SNPs R141L and G153D are significantly associated with XFS in this black South African population. The AA genotype of G153D confers XFS risk in this population, as opposed to the GG genotype described in all other populations, suggesting that unidentified genetic or environmental factors independent of these LOXL1 SNPs may influence phenotypic expression of the syndrome.
  
  
  CONCLUSIONS
  Elucidation of the role of genetic factors, including the LOXL1 gene, in XFS will facilitate identification of individuals predisposed to developing this condition.
authors.affiliation: Ophthalmology Department, Stellenbosch University and Tygerberg Academic Hospital, Tygerberg 7505, South Africa. robynrautenbach@gmail.com
authors.forename: Robyn M
authors.initials: RM
authors.lastname: Rautenbach
authors.forename: Soraya
authors.initials: S
authors.lastname: Bardien
authors.forename: Justin
authors.initials: J
authors.lastname: Harvey
authors.forename: Ari
authors.initials: A
authors.lastname: Ziskind
mesh_terms: D000368:Aged; D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D017889:Exfoliation Syndrome / Q000175:diagnosis / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D013019:South Africa
chemical_list: D000594:Amino Acid Oxidoreductases; C445313:LOXL1 protein, human