Purpose
Androgenetic alopecia, commonly known as male
pattern baldness, is the most common type of progressive
hair loss disorder in men. The aim of this paper is to review
recent advances in understanding the pathophysiology and
molecular mechanism of androgenetic alopecia.
Methods
Using the PubMed database, we conducted a
systematic review of the literature, selecting studies pub-
lished from 1916 to 2016.
Results
The occurrence and development of androgenetic
alopecia depends on the interaction of endocrine factors and
genetic predisposition. Androgenetic alopecia is character-
ized by progressive hair follicular miniaturization, caused
by the actions of androgens on the epithelial cells of
genetically susceptible hair follicles in androgen-dependent
areas. Although the exact pathogenesis of androgenetic
alopecia remains to be clari
fi
ed, research has shown that it is
a polygenetic condition. Numerous studies have unequi-
vocally identi
fi
ed two major genetic risk loci for androge-
netic alopecia, on the X-chromosome AR
⁄
EDA2R locus and
the chromosome 20p11 locus.
Conclusions
Candidate gene and genome-wide association
studies have reported that single-nucleotide polymorphisms
at different genomic loci are associated with androgenetic
alopecia development. A number of genes determine the
predisposition for androgenetic alopecia in a polygenic fashion. However, further studies are needed before the
specific genetic factors of this polygenic condition can be
fully explaine
