The Use of B-Cell Polysome Profiling to Validate Novel RPL5 (uL18) and RPL26 (uL24) Variants in Diamond-Blackfan...

Area of Science:

• Genetics
• Molecular Biology
• Hematology

Background:

• Diamond-Blackfan anemia (DBA) is a rare bone marrow failure syndrome often caused by mutations in ribosomal protein genes.
• Current genetic testing for DBA frequently identifies variants of unknown significance, hindering diagnosis and treatment.
• Functional validation of these variants is crucial for understanding disease mechanisms.

Observation:

• This study optimized polysome profiling in primary B-cells to assess ribosomal subunit function.
• The optimized method was applied to two children with DBA and novel missense variants in RPL5 and RPL26.
• Both patients exhibited reduced 60S and 80S ribosomal fractions compared to an unaffected parent.

Findings:

• Polysome profiling effectively identified a large ribosomal subunit defect in DBA patients with novel variants.
• The technique demonstrated reduced large ribosomal subunit assembly or function in affected individuals.
• This functional assay provides a method to interpret variants of unknown significance in DBA.

Implications:

• Optimized polysome profiling serves as a valuable adjunctive tool for validating large ribosomal protein variants in DBA.
• This method can aid in the diagnosis and understanding of DBA pathogenesis.
• Further validation is needed across diverse DBA mutations and patient subgroups.