Abstract: The present invention relates to methods for testing for a predisposition or presence of androgenetic alopecia comprising testing a sample obtained from a prospective patient or from a person suspected of carrying a predisposition for androgenetic alopecia. The invention also relates to a genetic marker for androgenetic alopecia characterised in that the genetic marker is located in a chromosomal region of human chromosome 20p11 and wherein the genetic marker is selected from the group consisting of a single nucleotide polymorphism (SNP), variable number of tandem repeat (VNTR), microsatellites or short tandem repeats (STR). Further, the invention relates to a diagnostic composition for the detection of androgenetic alopecia or a predisposition therefore as well as to a kit.