IntroductionKeloid scars are benign fibroproliferative cutaneous lesions resulting from the overproduction of all components of the healing process, including fibroblasts, collagen, elastin, and proteoglycans; they can occur following burn injuries, lacerations, abrasions, surgery, piercings, vaccinations, and even minor skin trauma. They are unique in humans, and especially in genetically susceptible individuals from nonwhite populations (1-3). It has been estimated that about 15%-20% of Blacks, Hispanics, and Orientals suffer from keloids and there appears to be a genetic predisposition to keloid formation (4). Keloids can develop at every age, but they have a higher incidence between 10 and 30 years (1,3). A slight female predominance is also noted, but this could be related to the higher rate of earlobe piercing in females (3,5). The incidence rates of hypertrophic scarring vary from 40% to 70% following surgery to up to 91% following burn injuries (4). The alterations responsible for keloid formation are still unknown, but it is thought that Background/aim: Scars develop at the end of the natural wound-healing process and are characterized by excessive collagen deposition, particularly types I and III collagen. This study aimed to investigate the genetic association of COL1A1 −1997 G/T (rs1107946) and COL1A1 Sp1 +1245 G/T (rs1800012) polymorphisms with the incidence of scars.
Materials and methods:A case-control association study was conducted with 84 volunteers from Jeddah, Saudi Arabia (47 patients and 37 controls). The allele frequency distribution and nucleotide genotypes of −1997 G/T, +1245 G/T were ascertained by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis.Results: Our results indicated that the distribution of COL1A1 (rs1107946) genotypes was significantly different between patients and controls (P = 0.00). The incidence of COL1A1 (rs1107946) genotype GG was significantly associated with a risk of scars. The distribution of the (rs1107946) genotype was drastically higher in women with scars (P= 0.00). One haplotype block in COL1A1 was documented by the pair-wise linkage disequilibrium between the single nucleotide polymorphisms (SNPs). The frequency of the GG haplotype constructed by the two SNPs was robustly high and associated with risk of scars.
Conclusion:Our results strengthen the evidence for the association between polymorphisms of −1997 G/T, +1245 G/T of the COL1A1 gene in the genetic etiology of keloid scars.