Hypertrophic post‐acne scarring is associated with a single nucleotide polymorphism (rs243865) in the matrix metalloproteinase‐2 gene

Aberrant tissue expression of matrix metalloproteinases has been observed in acne. Our objective was to study the relevance of MMP-2 (-1306 C/T, rs243865) and TIMP-2 (-418 G/C, rs8179090) single nucleotide polymorphisms (SNP) in acne and post-acne scarring.512 patients (169 having acne without scarring, 319 having atrophic acne scarring, 24 having hypertrophic acne scarring) and 161 age-matched controls were recruited from the Dermatology Outpatient Department after obtaining informed written consent. Venous blood (5 ml) was collected for genotyping by Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (RFLP) method. The severity of acne and acne-scarring were graded.Males had a significantly increased risk of developing severe acne (P = 0.012), extra-facial acne (P = 0.047) and extra-facial acne scarring (P = 0.0001). The presence of inflammatory acne positively correlated with severity of scarring (P = 0.001). Subjects with a homozygous CC genotype of MMP-2 (-1306 C/T) had 1.0, 7.8 and 8.2 times the odds of developing hypertrophic scarring when compared to controls (P = 0.05, 95 % CI: 0.7-1.6), subjects having acne without scarring (P = 0.047, 95 % CI: 1.0-59.9) and subjects having atrophic scarring, respectively (P = 0.041, 95 % CI: 1.1-59.9).A significant association was observed between hypertrophic post-acne scarring and the CC genotype of MMP-2 (-1306 C/T).