Genetics of keloid scarring

Barbara Shih, Ardeshir Bayat

Keloid scarring, also known as keloid disease (KD), is a common, abnormally raised fibroproliferative cutaneous lesion that can occur following even minor skin trauma. The aetiopathogenesis of KD has remained an enigma todate compounded by an ill-defined clinical management. There is strong evidence suggesting a genetic susceptibility in individuals affected by KD, including familial heritability, common occurrence in twins and high prevalence in certain ethnic populations. This review aims to address the genetic aspects of KD that have been described in present literature that include inheritance patterns, linkage studies, case-control association studies, whole genome gene expression microarray studies and gene pathways that were significant in KD. In addition to our clinical and scientific background in KD, we used search engines, Scopus, Scirus and PubMed, which searched for key terms covering various genetic aspects of KD. Additionally, genes reported in seven whole genome gene expression microarray studies were separately compared in detail. Our findings indicate a varied inheritance pattern in KD (predominantly autosomal dominant), linkage loci (chromosomes 2q23 and 7p11), several human leukocyte antigen (HLA) alleles (HLA-DRB1*15, HLA-DQA1*0104, DQ-B1*0501 and DQB1*0503), negative candidate gene case-control association studies and at least 25 dysregulated genes reported in multiple microarray studies. The major pathways reportedly proposed to be involved in KD include apoptosis, mitogen-activated protein kinase, transforming growth factor-beta, interleukin-6 and plasminogen activator inhibitor-1. In summary, involvement of more than one gene is likely to be responsible for susceptibility to KD. A better understanding of the genes involved in KD may potentially lead to the development of more effective diagnostic, therapeutic and prognostic measures.