Hypertrophic scar: a genetic hypothesis.

Two groups of patients with surgical and thermal wounds respectively were tested for aldehyde dehydrogenase 2 deficiency and assessed for the degree of hypertrophy of their scars. No association was found between the deficiency and hypertrophy of the scar. The frequency of hypertrophy was found to be 0.914 in the thermal injury group and 0.446 in the surgical wound group. This difference is statistically significant. The frequency data of the degree of hypertrophy in the two groups has been used to develop and test a single gene hypothesis for the origin of hypertrophic scar in the local Chinese population. It is postulated that the allele responsible for hypertrophy behaves as a dominant allele in the thermal injury group and as a recessive in the surgical wound group for the induction of hypertrophy.