Purpose: To investigate the possible role of UV-radiation in the development of conjunctival malignant melanoma. N-ras mutations are frequently found in cutaneous melanomas of sun-exposed body areas. UV-radiation is thought to induce mutations in the N-ras gene, that convert these genes into active oncogenes. The presence of N-ras mutations has been considered an indicator for UV-exposure in the development of melanomas on sun-exposed body sides.
Methods: We analyzed six paraffin-embedded conjunctival melanomas for mutations of the N-ras gene. Codons 12, 13 and 61 were amplified using polymerase chain reaction and sequenced.
Results: We could not detect point mutations of the N-ras gene in our samples.
Conclusion: Since we could not find deviations from the wild type sequence in the N-ras gene, our study does not support UV-exposure as being causative in the development of conjunctival melanoma.