Encephalocraniocutaneous lipomatosis with a mutation in the NF1 gene.

Encephalocraniocutaneous lipomatosis (ECCL) is a congenital hamartomatous disorder characterised by unilateral skin lesions, lipomas, and ipsilateral ophthamological and cerebral malformations. The disorder is thought to represent a localised form of Proteus syndrome. In this report, a child is described with ECCL and a de novo nonsense mutation in exon 29 (S1745X) of the neurofibromatosis type 1 (NF1) gene. Although it is possible that both ECCL and NF1 occur coincidentally in this patient, we favour the hypothesis that in exceptional cases a mutation in the NF1 gene might give rise to severe congenital malformations such as ECCL. Possible pathogenetic mechanisms for these malformations are discussed.