ABSTRACT
BACKGROUND: The etiology of idiopathic guttate hypomelanosis (IGH) remains uncertain; however, solar exposure and heredity have been proposed as causative factors. OBJECTIVE: To explore the genetic predisposition to the development of IGH. METHODS: A comparative case-control study was performed at a dermatology department at a university hospital. Forty-seven subjects (22 renal transplant patients and 25 controls) were enrolled. Clinical examination and human leukocyte antigen (HLA) determination were performed. RESULTS: In the group of subjects with HLA-DQ3 (10/13, P = 0.025), there was a statistically significant (P < 0.05) positive association for the presence of IGH; in the group of subjects with HLA-DR8 (6/6, P = 0.023), there was a statistically significant negative association for the presence of IGH. CONCLUSIONS: The presence of HLA-DQ3 in patients with IGH suggests a genetic basis in a group of renal transplant subjects. HLA-DR8 was found in patients without IGH, and it could play a role as a "protective factor" preventing subjects from developing IGH.