Ribosomal Protein Gene Deletions in Diamond Blackfan Anemia

Diamond Blackfan anemia is a congenital bone marrow failure syndrome characterized by hypoproliferative anemia, often with associated physical abnormalities. Perturbations of the ribosome appear critically important to the development of DBA, as alterations in 9 different ribosomal protein genes have been identified in multiple unrelated families, along with rarer abnormalities of additional ribosomal proteins. However, presently only 50-60% of patients have an identifiable genetic lesion by ribosomal protein gene sequencing. Using genome-wide SNP array to evaluate for regions of recurrent copy variation, we identified deletions at known DBA-related ribosomal protein gene loci in 17% (9/51) of patients without an identifiable mutation, including RPS19, RPS17, RPS26, and RPL35A [Illumina platforms] A total of 68 samples were analyzed on Illumina Omni1_Quad or Illumina OmniExpress Genotyping bead arrays; 51 affected probands, 1 affected sibling, 1 unaffected sibling, and 15 parents. [NimbleGen platform] 5 samples where a deletion was identified by SNP array and one sample where no deletion was identified were run on Nimblegen Human CGH 3x720K Whole-Genome Exon-Focused arrays for confirmation.