Mosaic NEK9 mutation, fibrous dysplasia and premature puberty in naevus comedonicus syndrome

Nevus comedonicus (NC) is a rare type of organoid epidermal nevus with comedones and inflammatory cysts 1 . It may be associated with extracutaneous manifestations (cataract, neurological and skeletal anomalies), defining NC syndrome 2 . Acne nevus, a clinically similar mosaic skin condition, is related to FGFR2, whereas postzygotic NEK9 mutations have been identified in four NC patients so far, including only one with NC syndrome 3 4 . Here we report on novel clinical findings, fibrous dysplasia and premature puberty in a case of NC syndrome associated with a NEK9 mutation.