Systematized naevoid hypertrichosis may herald Happle–Tinschert syndrome

Abstract

Happle-Tinschert syndrome (HTS) is characterized by segmentally arranged basaloid follicular hamartomas (BFHs) associated with osseous, dental and cerebral abnormalities.1 To date, fifteen additional cases have been described under this designation.2-5 The disorder is caused by a postzygotic mutation in the gene Smoothened (SMO).5,6 In several reports, patches of hypertrichosis have been documented.1, 2 The purpose of this article is to emphasize that such nevoid hypertrichosis may sometimes be a diagnostic marker of HTS.