Definition:

Aplasia cutis congenita (ACC) is a rare malformation characterized by localized congenital absence of the skin, mostly affecting the scalp vertex. It can occur in isolation or as part of a heterogeneous group of syndromes such as Adams-Oliver syndrome and Johanson-Blizzard syndrome. A mutation in the ribosomal GTPase BMS1 is identified in ACC. BMS1 has a role in processing of pre-rRNAs of the small ribosomal subunit. And mutations that affect ribosomal function can result in a cell cycle defect.