T1799A BRAF mutations in conjunctival melanocytic lesions

Area of Science:

• Ophthalmology
• Dermatology
• Molecular Biology

Background:

• Conjunctival melanocytic lesions, including nevi and melanoma, arise from specific molecular pathways.
• Understanding the genetic underpinnings of these lesions is crucial for diagnosis and treatment.
• The BRAF oncogene is frequently implicated in various melanomas.

Purpose of the Study:

• To investigate the prevalence of the T1799A BRAF oncogenic mutation in conjunctival melanocytic lesions.
• To differentiate the molecular events in conjunctival nevi, primary acquired melanosis (PAM), and melanoma.
• To explore potential differences in mutation frequency based on patient age.

Main Methods:

• Analysis of 48 surgically excised conjunctival lesions (28 nevi, 15 PAM, 5 melanomas).
• Detection of the BRAF T1799A mutation using a commercial kit and direct DNA sequencing.
• Examination of BRAF mutation status in nevi from pediatric and adult patients.

Main Results:

• The T1799A BRAF mutation was detected in 50% of conjunctival nevi.
• No BRAF T1799A mutations were found in conjunctival primary acquired melanosis (PAM) lesions.
• The mutation was present in 40% of conjunctival melanomas, with similar frequencies in nevi across age groups.

Conclusions:

• Conjunctival nevi exhibit a high frequency of BRAF mutations, mirroring findings in skin nevi.
• The BRAF mutation appears to be an early event in conjunctival nevus development, distinct from PAM.
• Further research is needed to determine the clinical significance of BRAF mutations in conjunctival lesions.