2. uluslararası kanser ve iyon kanalları kongresi, İzmir, Türkiye, 22 - 24 Eylül 2019, cilt.44, sa.2, ss.39
OBJECTIVES: The most frequently diagnosed malignant ocular tumor of
infancy and childhood is Retinoblastoma. Due to the mutation on the q14 on
chromosome 13 causes the retinoblastoma. There are two types of basic gene
mutations: genetic and sporadic. This cancer is initiated by RB1 mutation,
responsible for the cell cycle regulation and genome stability in the cells of the
retina in children under 5 years old. The retinoblastoma comprises about 40%
inherited mutations, 10% of germline mutations of RB1 inherited from an affected
parent, and 30% from de-novo germline mutations.
MATERIAL&METHODS: Methylation of the RB1 gene on promoter region
is unknown. The results obtained by MLPA analysis and sequence analysis
were investigated for RB1 gene methylation in patients without RB1 mutation.
The methylation determination is done with OneStep qMethyl-PCR Kit using
a Real-Time PCR system. Methylation changes were investigated in peripheral
blood samples of 60 patients with retinoblastoma, 18% of the patients (11/60)
had bilateral and 82% of patients (49/60) had unilateral disease and 52 healthy
controls.
RESULTS: The mean methylation levels of 60 retinoblastoma patients and 52
healthy controls were 35% and 34%, respectively. Mann Whitney U test was
compared between the patient and healthy controls and no statistically significant
difference was detected between the two groups (p = 0.882).
CONCLUSIONS: The promoter methylation levels in RB1 gene patients having
familial history was believed to be large deletion and duplication and small indel
absence mutations in the RB1 gene are not effective especially in the etiology of
heritable retinoblastoma.
Keywords: Retinoblastoma, RB1 gene mutation, Promoter Methylation