Analysis of familial factors using the basic and specific (BASP) classification in Korean patients with androgenetic alopecia

Background: The mechanisms and inheritance of androgenetic alopecia (AGA) have yet to be elucidated. Several clinical studies suggest that a predisposition to AGA is affected by a variety of paternal and/or maternal hereditary factors. No previous study has addressed the association of AGA with family history based on the pattern of hair loss. Objectives: The purpose of this study was to investigate paternal and/or maternal genetic influences in each type of hair loss pattern using the basic and specific (BASP) classification and to explore whether the morphology of AGA tends to be inherited in family members. Methods: Between October 2007 and September 2008, 1220 Korean participants, 998 male and 222 female, were classified according to the BASP classification at 13 university dermatologic centers. Information was collected using a standard questionnaire and BASP classification sheet. Results: Parental influences on anterior hairline shape in men were predominantly from the paternal side, whereas these effects were less notable in women. In the absence of a family history, statistical analysis showed a higher frequency for early-onset AGA than late-onset AGA (Pearson χ² P < .05). Basic types of hair loss had a higher degree of inheritance from the paternal side of the family, regardless of specific type. Limitations: The evaluation of hair loss pattern and family history was done by the patients. Conclusions: Familial factors affecting the morphology of AGA differ between male and female individuals, and for each type of BASP classification.