Functional assays for the RPS29 mutations. (A) Quantitative RT-PCR for RPS29 expression was performed on peripheral blood–derived lymphoblasts and primary fibroblast RNA samples from the proband from family NCI-193 (p.I31F) and family NCI-38 (p.I50T) and an unaffected control individual WT RPS29. The figure shows the combined data from 3 plates for lymphoblasts, and data for 1 plate for the fibroblasts, normalized using 2 endogenous controls (ACTB and GAPDH), for the short and long isoforms of RPS29. (B) Northern blot analysis of pre-rRNA processing was performed with a hybridization probe to 18SE/ITS1 (probe γ) using activated lymphocytes⁹  recovered from the peripheral blood from the proband (III-3) in family NCI-193 (p.I31F) and an unaffected control individual with WT RPS29.