title: Association study of sorbitol dehydrogenase -888G>C polymorphism with type 2 diabetic retinopathy in Caucasian-Brazilians.
abstract: Diabetic retinopathy (DR) is a common chronic complication of diabetes and remains the leading cause of blindness in working-aged people. Hyperglycemia increases glucose flux through the polyol pathway, in which aldose reductase converts glucose into intracellular sorbitol, which is subsequently converted to fructose by sorbitol dehydrogenase (SDH). The accelerated polyol pathway triggers a cascade of events leading to retinal vascular endothelial dysfunction and the eventual development of DR. Polymorphisms in the gene encoding aldose reductase have been consistently associated with DR. However, only two studies have analyzed the relationship between polymorphisms in the gene encoding SDH (SORD) and DR. In this case-control study, we investigated whether the -888G > C polymorphism (rs3759890) in the SORD gene is associated with the presence or severity of DR in 446 Caucasian-Brazilians with type 2 diabetes (241 subjects with and 205 subjects without DR). The -888G > C polymorphism was also examined in 105 healthy Caucasian blood donors, and the genotyping of this polymorphism was carried out by real-time PCR. The genotype and allele frequencies of the -888G > C polymorphism in patients with type 2 diabetes were similar to those of blood donors (G allele frequency = 0.16 in both groups of subjects). Similarly, the genotype and allele frequencies in patients with DR or the proliferative form of DR were similar to those of patients without this complication (P > 0.05 for all comparisons). Thus, our findings suggest that the -888G > C polymorphism in the SORD gene is not involved in the pathogenesis of DR in type 2 diabetes.
authors.affiliation: Laboratory of Human Molecular Genetics, Universidade Luterana do Brasil, Canoas, Brazil.
authors.forename: Fábio Netto
authors.initials: FN
authors.lastname: Ferreira
authors.forename: Daisy
authors.initials: D
authors.lastname: Crispim
authors.forename: Luís Henrique
authors.initials: LH
authors.lastname: Canani
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Gross
authors.forename: Kátia Gonçalves
authors.initials: KG
authors.lastname: dos Santos
mesh_terms: D000328:Adult; D000449:Aldehyde Reductase / Q000235:genetics; D001938:Brazil; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D003930:Diabetic Retinopathy / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007064:L-Iditol 2-Dehydrogenase / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D060888:Real-Time Polymerase Chain Reaction; D013012:Sorbitol / Q000378:metabolism; D044465:White People / Q000235:genetics*
chemical_list: D013012:Sorbitol; D007064:L-Iditol 2-Dehydrogenase; D000449:Aldehyde Reductase
keywords: AGEs; AR; Advanced glycation end-products; Aldose reductase; DR; Diabetic retinopathy; NPDR; Non-proliferative diabetic retinopathy; OR; Odds ratio; PDR; PKC; Proliferative diabetic retinopathy; Protein kinase C; SDH; SORD; Sorbitol dehydrogenase; diabetic retinopathy; gene encoding sorbitol dehydrogenase; polymorphism; polyol pathway; sorbitol dehydrogenase; type 2 diabetes