Here, we report that different variants in RPL9, a gene that has not been definitively described in DBA or other human diseases, drive similar defects in the processing of pre-rRNA during ribosome biogenesis yet reveal markedly different downstream effects on the TP53 pathway, erythrocyte development, metabolism, and the ability of ribosomes to recognize mRNA stop codons. The gene discussed is RPL9; the disease is Diamond-Blackfan anemia.