T1799A BRAF mutations in conjunctival melanocytic lesions.
OBJECTIVE
To gain a better understanding of the molecular events leading to the development of conjunctival melanocytic lesions and conjunctival melanoma, this study was conducted to investigate the presence of T1799A BRAF oncogenic mutation in these lesions.


METHODS
Forty-eight surgically excised conjunctival melanocytic lesions from 48 patients were examined for the presence of the BRAF T1799A mutation. Twenty-eight lesions were conjunctival nevi, of which 20 were excised from children younger than 18 years. Fifteen lesions were conjunctival primary acquired melanosis (PAM; 11 without atypia and 4 with atypia) and five were conjunctival melanomas. To detect the BRAF T1799A mutation, both a newly developed kit (Mutector; TrimGen, Sparks, MD) and direct DNA sequence analysis of exon 15 after PCR amplification were used.


RESULTS
The T1799A BRAF mutation was identified in 14 of 28 (50%) conjunctival nevi analyzed, but in none of the 15 conjunctival PAMs, with and without atypia. The T1799A BRAF mutation was identified in two of the five (40%) conjunctival melanomas. There was no difference in the BRAF mutation detected in conjunctival nevi in children or adults, as the BRAF mutation was detected in 50%.


CONCLUSIONS
The results showed that conjunctival nevi, similar to skin nevi, have a high frequency of oncogenic BRAF mutations. Furthermore, the results suggest that the oncogenic event leading to BRAF mutations affect only conjunctival nevi and not conjunctival PAM. The clinical significance of these observations remains to be determined.
Goldenberg-Cohen
Nitza
N
Wilmer Eye Institute, Department of Otolaryngology/Head and Neck Surgery, Division of Head and Neck Cancer Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Cohen
Yoram
Y
Rosenbaum
Eli
E
Herscovici
Zvi
Z
Chowers
Itay
I
Weinberger
Dov
D
Pe'er
Jacob
J
Sidransky
David
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003230:Conjunctival Neoplasms / Q000235:genetics*; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005091:Exons / Q000235:genetics; D006801:Humans; D008545:Melanoma / Q000235:genetics*; D008548:Melanosis / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D009508:Nevus, Pigmented / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D017422:Sequence Analysis, DNA
D004273:DNA, Neoplasm; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf