AOS is a congenital disease characterized by aplasia cutis congenita, transverse limb defects, and CMTC1,2
. It was initially described in 1945 by Adams and Oliver1
. The disease largely has an autosomal dominant mode of inheritance, although autosomal recessive and sporadic modes often occur as well3,4
. Our patient had no family history of congenital scalp or limb defects. Therefore, this case was likely a sporadic one.
The limb defects, the most common feature of this disease, are usually asymmetric. The lower limbs are more susceptible than the upper limbs. The range of involvement includes brachydactyly, syndactyly, agenesis of fingernails or toenails, loss of the terminal phalanges, or even more severe defects such as the complete absence of a finger, toe, hand, foot, or limb5,6
. Our patient had interdigital webs of the 2nd and 3rd toes and absence of the 3rd toenail on the right. Scalp defects are the second most frequent finding in AOS4
. The scalp lesions occasionally extend through the skull deformities. Our patient exhibited only a scalp defect and skull thinning. The lesion was confirmed as aplasia cutis congenita upon histopathological examination. Other associated defects include CMTC, central nervous system and cardiovascular malformations, accessory nipples, microphthalmia, and cleft lip7,8
. Among these defects, our patient exhibited only CMTC.
Although the exact pathogenesis of AOS remains unknown, vascular impairment during embryogenesis has been proposed as a possible mechanism. In order to identify the genetic cause of AOS, Verdyck et al.9
evaluated a family with 10 affected individuals over four generations. However, they failed to find any disease-causing mutations.
Various expressions of AOS have been reported. This report shows that AOS without major organ abnormalities does not necessarily alter the normal lifespan. Additionally, if a newborn presents with aplasia cutis congenita and limb defects, dermatologists should consider AOS by conducting an evaluation of the central nervous system and looking for cardiovascular, gastrointestinal, and genitourinary malformations.