Eleven Pairs of Japanese Male Twins Suggest the Role of Epigenetic Differences in Androgenetic Alopecia

The study investigated the role of environmental factors in androgenetic alopecia (AGA) by looking at 11 pairs of identical Japanese male twins. The study found that five of the 11 pairs showed baseline differences in hair volume, either significant or moderate, at the initial consultation. After one year of medication, four of those five still showed moderate differences. The twin in each pair with less hair volume had a more advanced stage in the modified Norwood/Hamilton classification and earlier onset of AGA compared to the twin with more hair volume. The study suggests that delay of onset is an important factor in keeping a satisfying hair volume.