Diamond-Blackfan anemia (DBA), an inherited bone marrow failure syndrome 
characterized by anemia that usually presents before the first birthday or in 
early childhood, is associated with birth defects and an increased risk of 
cancer. Although anemia is the most prominent feature of DBA, the disease is 
also characterized by growth retardation and congenital malformations, in 
particular craniofacial, upper limb, heart, and urinary system defects that are 
present in approximately 30%-50% of patients. DBA has been associated with 
mutations in seven ribosomal protein (RP) genes, RPS19, RPS24, RPS17, RPL35A, 
RPL5, RPL11, and RPS7, in about 43% of patients. To continue our large-scale 
screen of RP genes in a DBA population, we sequenced 35 ribosomal protein genes, 
RPL15, RPL24, RPL29, RPL32, RPL34, RPL9, RPL37, RPS14, RPS23, RPL10A, RPS10, 
RPS12, RPS18, RPL30, RPS20, RPL12, RPL7A, RPS6, RPL27A, RPLP2, RPS25, RPS3, 
RPL41, RPL6, RPLP0, RPS26, RPL21, RPL36AL, RPS29, RPL4, RPLP1, RPL13, RPS15A, 
RPS2, and RPL38, in our DBA patient cohort of 117 probands. We identified three 
distinct mutations of RPS10 in five probands and nine distinct mutations of 
RPS26 in 12 probands. Pre-rRNA analysis in lymphoblastoid cells from patients 
bearing mutations in RPS10 and RPS26 showed elevated levels of 18S-E pre-rRNA. 
This accumulation is consistent with the phenotype observed in HeLa cells after 
knockdown of RPS10 or RPS26 expression with siRNAs, which indicates that 
mutations in the RPS10 and RPS26 genes in DBA patients affect the function of 
the proteins in rRNA processing.