Congenital Hypotrichosis Due to Short Anagen Phase

The document reported on two cases of congenital hypotrichosis, where children had persistently short, fine hair from birth due to a short anagen phase, rather than slow hair growth. The condition was found to potentially have an autosomal dominant inheritance pattern and resolved spontaneously during puberty. Scanning electron microscopy showed a cuticular pattern typical of thin hair. The maximal hair lengths and estimated anagen durations were 6 cm and 176 days for patient 1, and 12 cm and 400 days for patient 2. The study confirmed the existence of short anagen cycles as a cause for short hair, a condition that may be treatable with minoxidil, which can prolong the anagen phase. These cases were the first documented instances of congenital hypotrichosis due to short anagen without associated abnormalities.