Genetic Testing in Retinoblastoma: New Applications

Liquid biopsy and molecular profiling are expanding the diagnostic and prognostic role of genetic testing in retinoblastoma.

By
Soumaya Bouhout, MD
Arun D. Singh, MD
September 1, 2026
9 min

Retinal Physician

Objective:

To explore the expanding role of genetic testing in retinoblastoma, particularly through liquid biopsy and molecular profiling.

Approach:

Overview of Genetic Testing: Explores the evolution of genetic testing in retinoblastoma, highlighting its transition from solely detecting germline mutations to encompassing diagnostic and prognostic applications.

Key Findings:

Aqueous humor liquid biopsy demonstrated a feasibility rate of 98% with a sensitivity of 98% and specificity of 100% for detecting active disease.
Circulating tumor DNA can be detected in up to 85% of untreated unilateral retinoblastoma patients, reflecting tumor burden.
Chromosome 6p gain, 7q gain, and MYCN amplification are associated with poorer globe salvage outcomes.
Blood ctDNA levels correlate with ocular disease progression and regression following intra-arterial chemotherapy.

Interpretation:

Genetic testing in retinoblastoma is evolving to include liquid biopsy and molecular profiling, enhancing diagnostic sensitivity and prognostic capabilities.

Limitations:

False-negative results may occur in small tumors or those with low tumor DNA shedding.
The number of reported patients in studies is small, and further validation is needed.