<unk>  is a disorder of the hair<unk>  leading to increased fragility of the shaft, with no identifiable biochemical disturbance, also with an unknown prevalence.
Intermittent hair–follicle dystrophy
X-linked hypertrichosis
Linear atrophoderma of Moulin
Follicular atrophoderma
Pure hair-nail type ectodermal dysplasia
Hypohidrotic ectodermal dysplasia
Focal facial dermal dysplasia
Central centrifugal cicatricial alopecia