Abstract
Purpose:
Biallelic inactivation of RB1 is the hallmark of retinoblastoma. The current genetic testing protocol of RB1 involves screening of entire gene that requires extended time and higher cost. Hence the objective of this study is to develop a new strategy for rapid screening of retinoblastoma.
Methods:
Twenty one randomly selected cases of retinoblastoma were analyzed using conventional methods of Sanger sequencing and Multiplex Ligation dependent Probe Amplification to detect point mutations and deletions/duplications respectively using a step-wise strategy. The analysis was performed in 12 blood (bilateral) and 9 tumor (unilateral) samples of probands. The identified point mutation/deletion was further checked in family members.
Results:
A new sequential protocol was adopted for mutation detection and it is based on the relative frequency of (i) CGA and other stop codon mutations, (ii) deletions and (iii) other recurrent mutations from the database and published literature. Using this protocol, it was possible to detect and confirm genetic changes in 76% of cases within four weeks in the probands. Further analysis of the family members was carried out within one week.
Conclusions:
The comprehensive genetic analysis of tumor and blood samples of probands along with their family members using our new strategy requires less time with the reduced cost by at least 50%. This would help the clinic to provide effective genetic counseling in a quick turnaround time. Further, the additional protocols such as DNA methylation, Microsatellite analysis, Next Generation Sequencing might enhance the rate of mutation detection.