Molecular mechanism of extracutaneous tumours in patients with basal cell nevus syndrome

Abstract

Basal cell nevus syndrome (BCNS) is a rare genetic disorder accompanied by a broad variety of tumours, of which basal cell carcinomas and odontogenic keratocysts are the most common. BCNS is caused by a germline or postzygotic mutation in eitherPTCH1orSUFU. As BCNS is a rare disease, it is difficult to establish whether less frequently occurring tumours are actually part of the syndrome. In this study, the molecular mechanism behind four extracutaneous tumours in patients with BCNS was elucidated. A leiomyoma of the testis and meningioma were confirmed to be associated with BCNS in two patients by presence of a second mutation or loss of heterozygosity inPTCH1. In a meningioma of a patient with a mosaic postzygoticPTCH1mutation an association could not be conclusively confirmed.SUFUwas probably not involved in the development of a thyroid carcinoma in a patient with a germlineSUFUmutation. Hence, we have proven that meningioma and leiomyoma of the testis are rare extracutaneous tumours that are part of BCNS.