Aims: Ophthalmic pterygium is a potentially vision-threatening lesion of unkn own etiology, related to an exposure to solar light. Mutations to the ras genes are frequently observed in lesions related to an exposure t...Aims: Ophthalmic pterygium is a potentially vision-threatening lesion of unkn own etiology, related to an exposure to solar light. Mutations to the ras genes are frequently observed in lesions related to an exposure to solar light. The pr esent study aims at screening pterygia for mutations at codons 12 and 13 of the ras genes. Methods: In all, 50 pterygia were examined, together with respective blood samples and specimens of normal conjunctiva. A PCR reaction was performed to amplify sequences containing codons 12 and 13 of Ki-ras, H-ras, and N-ras. An RFLP analysis was then performed to detect point mutations at codon 12. The mutational status at codons 12 and 13 was further explored with sequencing of PC R products. Results: RFLP analysis revealed Ki-ras mutations at codon 12 in fiv e (10%) of pterygia, whereas H-ras or N-ras mutations were not observed. Sequ encing confirmed Ki-ras mutations at codon 12 and revealed absence of mutations at codon 13. The presence of Ki-ras mutations was significantly correlated wit h postoperative recurrence (P=0.02) and young age (P=0.04). Mutations were not o bserved in specimens of blood or normal conjunctiva for any of the genes examine d. Conclusions: The absence of Nras mutations is in agreement with previous repo rts concerning mucosal lesions. The detection of Ki-ras mutations and the assoc iation with postoperative recurrence implies a possible role of Ki-ras in the c linical profile of pterygium. The mechanism of Ki-ras mutations is unclear and could be independen t of the action of UV light.展开更多
文摘Aims: Ophthalmic pterygium is a potentially vision-threatening lesion of unkn own etiology, related to an exposure to solar light. Mutations to the ras genes are frequently observed in lesions related to an exposure to solar light. The pr esent study aims at screening pterygia for mutations at codons 12 and 13 of the ras genes. Methods: In all, 50 pterygia were examined, together with respective blood samples and specimens of normal conjunctiva. A PCR reaction was performed to amplify sequences containing codons 12 and 13 of Ki-ras, H-ras, and N-ras. An RFLP analysis was then performed to detect point mutations at codon 12. The mutational status at codons 12 and 13 was further explored with sequencing of PC R products. Results: RFLP analysis revealed Ki-ras mutations at codon 12 in fiv e (10%) of pterygia, whereas H-ras or N-ras mutations were not observed. Sequ encing confirmed Ki-ras mutations at codon 12 and revealed absence of mutations at codon 13. The presence of Ki-ras mutations was significantly correlated wit h postoperative recurrence (P=0.02) and young age (P=0.04). Mutations were not o bserved in specimens of blood or normal conjunctiva for any of the genes examine d. Conclusions: The absence of Nras mutations is in agreement with previous repo rts concerning mucosal lesions. The detection of Ki-ras mutations and the assoc iation with postoperative recurrence implies a possible role of Ki-ras in the c linical profile of pterygium. The mechanism of Ki-ras mutations is unclear and could be independen t of the action of UV light.
