Loose Anagen Syndrome in One Identical Twin Girl

Loose anagen syndrome (LAS) is a hair disorder characterized by insufficient anchoring of the hair follicle to the scalp, often due to an autosomal dominant or sporadic mutation in the gene encoding keratin 6. This case report described a 2-year-old girl with LAS type B, which typically presents in young, light-haired girls as unruly, uncombable hair with diminished growth. Interestingly, her identical twin sister was unaffected. The diagnosis was confirmed through a painless hair pull test, which showed anagen hairs with ruffled cuticles on trichoscopy, thus avoiding unnecessary referrals and diagnostic tests.