Abstract

GENETIC ETIOLOGY OF KELOID SCARS: SIGNIFICANCE OF RS1801184 AS A BIOMARKER OF DEVELOPING PATHOLOGICAL SCARS.

Sanaa E. Tork, Sabah A. Linjawi* and Najwa A. Mohammed

Abstract

Keloid scar is a benign hyper-proliferative growth of dermal fibroblasts characterized by an abnormal excessive deposition of extracellular matrix components especially collagen. It is well known that keloid can be triggered in genetically susceptible individuals. Collagen synthesis is 20 times more proliferative in keloid compared to normal skin. In the current study, the association between rs1800255 (exon 30 G/A) and COL3A1 rs1801184 (exon 32 T/C) polymorphisms and incidence of scars in Jeddah city population was evaluated. The distribution of allele frequency and nucleotide genotypes of exon 30 G/A (rs1800255) and exon 32 T/C (rs1801184) polymorphisms were ascertained in 84 volunteers from Jeddah (47 patients and 37 controls) by using a combination of polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (RFLP). Our results demonstrated that the distribution of exon 32 T/C (rs1801184) genotypes was significantly different between patients and controls (P=0.001). Notably, the incidence of COL3A1exon 32 T/C (rs1801184) TT genotype was significantly correlated with risk of scars. Likewise, a highly significant difference in the genotype distribution of (rs1801184) was noticed (P=0.002) in women with scars. One haplotype block in COL3A1 was documented by the pair-wise linkage disequilibrium between the SNPs. The frequency of GT diplotype constructed by the two SNPs was markedly high and was associated with risk of scars. This study confirms and strengthens the evidence for a strong association between polymorphisms of exon 32 T/C rs1801184 COL3AI gene in the genetic etiology of keloid scars.

Keywords: Collagen III, Keloid scars, RFLP-PCR, SNP, Haplotype.