Congenital skin pedicles with or without amniotic band sequence: Extending the human phenotype resembling mouse disorganization.

Congenital skin pedicles are very rare and usually described in association with multiple congenital anomalies. Here, we report on six patients with congenital pedicle skin hamartomatous lesions. Two patients showed a single skin pedicle lesion, one of whom was also shown to have 22q11.2 microdeletion syndrome, and four patients also had severe limb anomalies for which they were originally diagnosed with amniotic band sequence (ABS). We propose that all these infants instead show various forms of the phenotype resembling disorganization in the mouse. This article supports previous reports suggesting that "Disorganization-like" mutations may cause cases with apparent ABS. Owing to these reports, we propose the hypothesis that hamartomatous skin pedicles and "ABS plus" are different phenotypes of the human disorder resembling disorganization.