title: MMP-1 promoter genotype and haplotype association with posterior tibial tendinopathy.
abstract: OBJECTIVE
  Posterior tibial tendon (PTT) is particularly vulnerable and its insufficiency is recognized as the main cause of adult acquired flatfoot. Some patients have a predisposition without clinically recognized cause, suggesting that individual characteristics play an important role in tendinopathy. The objective of the present study is to investigate the association of -519 (rs1144393) matrix metalloproteinase-1 (MMP-1) polymorphism and the -1607 (rs1799750) and -519 MMP-1 haplotypes and risk of PTT dysfunction.
  
  
  METHODS
  The test group included 50 females who presented PTT dysfunction Grade 2 or 3, and who were submitted to surgical treatment, with histopathological examination of the tendon and magnetic resonance image (MRI) confirming tendinopathy, while the control group was 100 asymptomatic women who present intact PTT at MRI. We analyzed functional polymorphisms MMP-1 and their haplotypes using polymerase chain reaction and restriction fragment length analysis.
  
  
  RESULTS
  There was a significant difference in the presence of the different alleles and genotypes between the control group and test group for the MMP-1 gene (p≤0.01). The G allele of the -519 MMP-1 polymorphism increased susceptibility to degeneration in the PTT tendon and seems to be a genetic risk factor. Global haplotype analysis indicated a significant difference between both groups (p<0.0001). Haplotypes G-2G and A-2G had statistically significant risk effect on PTT insufficiency. G-2G, p<0.001; OR=5.72 (CI, 2.84-11.52) and A-2G p=0.002, OR=3.95 (CI, 1.65-9.44).
  
  
  CONCLUSIONS
  According to our results, -519 MMP-1 isolated and -1607/-519 MMP-1 haplotypes are associated to tendinopathy in posterior tibial tendon.
authors.affiliation: Department of Cell Biology, University Federal of Paraná, Curitiba, PR, Brazil.
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Baroneza
authors.affiliation: Department of Orthopedics and Traumatology, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Godoy-Santos
authors.affiliation: Department of Orthopedics and Traumatology, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ferreira Massa
authors.affiliation: Department of Cell Biology, University Federal of Paraná, Curitiba, PR, Brazil.
authors.forename: Francielle
authors.initials: F
authors.lastname: Boçon de Araujo Munhoz
authors.affiliation: Department of Orthopedics and Traumatology, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Túlio
authors.initials: T
authors.lastname: Diniz Fernandes
authors.affiliation: Department of Cell Biology, University Federal of Paraná, Curitiba, PR, Brazil. Electronic address: lemegsantos@gmail.com.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Leme Godoy dos Santos
mesh_terms: D016022:Case-Control Studies; D005260:Female; D056726:Genetic Association Studies; D006239:Haplotypes; D006801:Humans; D020781:Matrix Metalloproteinase 1 / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D037081:Posterior Tibial Tendon Dysfunction / Q000235:genetics*; D011401:Promoter Regions, Genetic
chemical_list: C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1
keywords: MMP-1 polymorphism; Risk factor; Tendinopathy; Tibial posterior tendon