Objective:

To identify genetic variants associated with autosomal dominant retinitis pigmentosa (RP) and improve diagnostic rates for the condition.

Key Findings:

• Variants in RNU4-2 and RNU6 genes were found in 153 affected individuals from 67 families.
• These variants are located in the three-way junction of the U4/U6 structure, interacting with spliceosomal proteins linked to autosomal dominant RP.
• Approximately 1.4% of RP cases that previously lacked a genetic diagnosis may be explained by these variants.

Interpretation:

The presence of RNU4-2 and RNU6 variants correlates with typical RP symptoms, but some carriers exhibit incomplete penetrance, complicating genetic counseling.

Limitations:

• Variants in noncoding RNA genes are often overlooked in routine genetic testing.
• The study may not encompass all genetic causes of RP, as it focuses on specific RNA variants.

Conclusion:

Incorporating spliceosomal RNA genes into genetic testing could enhance the identification of RP causes in undiagnosed patients.