@article {413,
	title = {Whole-exome sequencing identifies novel variants in PNPT1 causing oxidative phosphorylation defects and severe multisystem disease.},
	journal = {Eur J Hum Genet},
	volume = {25},
	year = {2016},
	month = {2016 01},
	pages = {79-84},
	abstract = {<p>Recent advances in next-generation sequencing strategies have led to the discovery of many novel disease genes. We describe here a non-consanguineous family with two affected boys presenting with early onset of severe axonal neuropathy, optic atrophy, intellectual disability, auditory neuropathy and chronic respiratory and gut disturbances. Whole-exome sequencing (WES) was performed on all family members and we identified compound heterozygous variants (c.[760C>A];[1528G>C];p.[(Gln254Lys);(Ala510Pro)] in the polyribonucleotide nucleotidyltransferase 1 (PNPT1) gene in both affected individuals. PNPT1 encodes the polynucleotide phosphorylase (PNPase) protein, which is involved in the transport of small RNAs into the mitochondria. These RNAs are involved in the mitochondrial translation machinery, responsible for the synthesis of mitochondrially encoded subunits of the oxidative phosphorylation (OXPHOS) complexes. Both PNPT1 variants are within highly conserved regions and predicted to be damaging. These variants resulted in quaternary defects in the PNPase protein and a clear reduction in protein and mRNA expression of PNPT1 in patient fibroblasts compared with control cells. Protein analysis of the OXPHOS complexes showed a significant reduction in complex I (CI), complex III (CIII) and complex IV (CIV). Enzyme activity of CI and CIV was clearly reduced in patient fibroblasts compared with controls along with a 33\% reduction in total mitochondrial protein synthesis. In vitro rescue experiments, using exogenous expression of wild-type PNPT1 in patient fibroblasts, ameliorated the deficiencies in the OXPHOS complex protein expression, supporting the likely pathogenicity of these variants and the importance of WES in efficiently identifying rare genetic disease genes.</p>},
	keywords = {Axons, Exome, Exoribonucleases, High-Throughput Nucleotide Sequencing, Humans, Intellectual Disability, Male, Mitochondria, Mutation, Optic Atrophy, Oxidative Phosphorylation, Pedigree, Protein Structure, Quaternary},
	issn = {1476-5438},
	doi = {10.1038/ejhg.2016.128},
	author = {Alodaib, Ahmad and Sobreira, Nara and Gold, Wendy A and Riley, Lisa G and Van Bergen, Nicole J and Wilson, Meredith J and Bennetts, Bruce and Thorburn, David R and Boehm, Corinne and Christodoulou, John}
}
@article {180,
	title = {Exome sequencing links mutations in PARN and RTEL1 with familial pulmonary fibrosis and telomere shortening.},
	journal = {Nat Genet},
	volume = {47},
	year = {2015},
	month = {2015 May},
	pages = {512-7},
	abstract = {<p>Idiopathic pulmonary fibrosis (IPF) is an age-related disease featuring progressive lung scarring. To elucidate the molecular basis of IPF, we performed exome sequencing of familial kindreds with pulmonary fibrosis. Gene burden analysis comparing 78 European cases and 2,816 controls implicated PARN, an exoribonuclease with no previous connection to telomere biology or disease, with five new heterozygous damaging mutations in unrelated cases and none in controls (P = 1.3 {\texttimes} 10(-8)); mutations were shared by all affected relatives (odds in favor of linkage = 4,096:1). RTEL1, an established locus for dyskeratosis congenita, harbored significantly more new damaging and missense variants at conserved residues in cases than in controls (P = 1.6 {\texttimes} 10(-6)). PARN and RTEL1 mutation carriers had shortened leukocyte telomere lengths, and we observed epigenetic inheritance of short telomeres in family members. Together, these genes explain ~7\% of familial pulmonary fibrosis and strengthen the link between lung fibrosis and telomere dysfunction.</p>},
	keywords = {Adult, Aged, Aged, 80 and over, Amino Acid Sequence, Case-Control Studies, Cells, Cultured, DNA Helicases, DNA Mutational Analysis, Exome, Exoribonucleases, Female, Genetic Association Studies, Genetic Predisposition to Disease, Humans, Idiopathic Pulmonary Fibrosis, Leukocytes, Lod Score, Male, Middle Aged, Molecular Sequence Data, Pedigree, Telomere, Telomere Shortening},
	issn = {1546-1718},
	doi = {10.1038/ng.3278},
	author = {Stuart, Bridget D and Choi, Jungmin and Zaidi, Samir and Xing, Chao and Holohan, Brody and Chen, Rui and Choi, Mihwa and Dharwadkar, Pooja and Torres, Fernando and Girod, Carlos E and Weissler, Jonathan and Fitzgerald, John and Kershaw, Corey and Klesney-Tait, Julia and Mageto, Yolanda and Shay, Jerry W and Ji, Weizhen and Bilguvar, Kaya and Mane, Shrikant and Lifton, Richard P and Garcia, Christine Kim}
}
