The CYLD p.R758X worldwide recurrent nonsense mutation detected in patients with multiple familial trichoepithelioma type 1, Brooke-Spiegler syndrome and familial cylindromatosis represents a mutational hotspot in the gene.

Background: Multiple familial trichoepithelioma type 1 (MFT1; MIM 601606), a rare monogenic skin disease with autosomal dominant inheritance, is characterized by the development of multiple skin-colored papules on the central area of the face, frequently occurring in the nasolabial area. The disease is associated with various mutations in the cylindromatosis (CYLD; MIM 605018) gene that are also responsible for familial cylindromatosis (FC) and Brooke-Spiegler syndrome (BSS).

Methods: Recently we have identified a Spanish MFT1 pedigree with two affected family members (father and daughter). Direct sequencing of the CYLD gene revealed a worldwide recurrent heterozygous nonsense mutation (c.2272C/T, p.R758X) in the patients.

Results: This mutation has already been detected in patients with all three clinical variants - BSS, FC and MFT1 - of the CYLD-mutation spectrum. Haplotype analysis was performed for the Spanish patients with MFT1, Dutch patients with FC and an Austrian patient with BSS, all of whom carry the same heterozygous nonsense p.R758X CYLD mutation.

Conclusions: Our results indicate that this position is a mutational hotspot on the gene and that patients carrying the mutation exhibit high phenotypic diversity.