ABSTRACT
Shwachman-Diamond syndrome (SDS) is a recessive disorder typified by bone marrow failure and predisposition to hematological malignancies. SDS is predominantly caused by deficiency of the allosteric regulator Shwachman-Bodian-Diamond syndrome that cooperates with elongation factor-like GTPase 1 (EFL1) to catalyze release of the ribosome antiassociation factor eIF6 and activate translation. Here, we report biallelic mutations in EFL1 in 3 unrelated individuals with clinical features of SDS. Cellular defects in these individuals include impaired ribosomal subunit joining and attenuated global protein translation as a consequence of defective eIF6 eviction. In mice, Efl1 deficiency recapitulates key aspects of the SDS phenotype. By identifying biallelic EFL1 mutations in SDS, we define this leukemia predisposition disorder as a ribosomopathy that is caused by corruption of a fundamental, conserved mechanism, which licenses entry of the large ribosomal subunit into translation.
Subject(s)
Mutation , Peptide Elongation Factors/genetics , Peptide Initiation Factors/biosynthesis , Ribonucleoprotein, U5 Small Nuclear/genetics , Shwachman-Diamond Syndrome/genetics , Shwachman-Diamond Syndrome/metabolism , Adolescent , Animals , Cells, Cultured , DNA Mutational Analysis , Disease Models, Animal , Disease Susceptibility , Female , Genome-Wide Association Study , Humans , Infant , Male , Mice , Mice, Transgenic , Models, Molecular , Pedigree , Peptide Elongation Factors/chemistry , Peptide Elongation Factors/metabolism , Phenotype , Protein Conformation , Ribonucleoprotein, U5 Small Nuclear/chemistry , Ribonucleoprotein, U5 Small Nuclear/metabolism , Shwachman-Diamond Syndrome/diagnosis , Structure-Activity Relationship , Whole Genome SequencingABSTRACT
Determining the genetic bases of age-related disease remains a major challenge requiring a spectrum of approaches from human and clinical genetics to the utilization of model organism studies. Here we report a large-scale genetic screen in mice employing a phenotype-driven discovery platform to identify mutations resulting in age-related disease, both late-onset and progressive. We have utilized N-ethyl-N-nitrosourea mutagenesis to generate pedigrees of mutagenized mice that were subject to recurrent screens for mutant phenotypes as the mice aged. In total, we identify 105 distinct mutant lines from 157 pedigrees analysed, out of which 27 are late-onset phenotypes across a range of physiological systems. Using whole-genome sequencing we uncover the underlying genes for 44 of these mutant phenotypes, including 12 late-onset phenotypes. These genes reveal a number of novel pathways involved with age-related disease. We illustrate our findings by the recovery and characterization of a novel mouse model of age-related hearing loss.
