Aplasia cutis congenita in monozygotic twins

Aplasia cutis congenita (ACC) is defined as complete or partial loss or absence of skin at birth and it can occur on any part of the body, but most commonly on the scalp. Single offspring with ACC have been reported in most case reports, but cases in twins are rarely reported. Here, we report two cases of ACC, monozygotic twin boys presented with scattered skin absence over the scalp vertex after birth. All the lesions presented as ulcers with no hair and healed with scars, otherwise, the twins were well developed mentally and physically. In addition, the whole exome sequencing of the twins and their parents might provide diagnosis and classification assistance.