TERT promoter mutations in ocular melanoma distinguish between conjunctival and uveal tumours

Background: Recently, activating mutations in the TERT promoter were identified in cutaneous melanoma. We tested a cohort of ocular melanoma samples for similar mutations. Methods: The TERT promoter region was analysed by Sanger sequencing in 47 uveal (ciliary body or choroidal) melanomas and 38 conjunctival melanomas. Results: Mutations of the TERT promoter were not identified in uveal melanomas, but were detected in 12 (32%) conjunctival melanomas. Mutations had a UV signature and were identical to those found in cutaneous melanoma. Conclusion: Mutations of TERT promoter with UV signatures are frequent in conjunctival melanomas and favour a pathogenetic kinship with cutaneous melanomas. Absence of these mutations in uveal melanomas emphasises their genetic distinction from cutaneous and conjunctival melanomas.