Happle-Tinschert syndrome (HTS) is a rare, sporadic, multisystem disorder characterized by hypo- and hyperpigmented skin patches following Blaschko's lines, plus acral skeletal and other abnormalities and is characterized by basaloid follicular hamartomas. HTS is caused by a postzygotic mutation in the SMO gene (c.1234C>T, p.Leu412Phe).