PMC:4573257 / 11569-13631 JSONTXT

{"project":"2_test","denotations":[{"id":"26189817-19616983-2053334","span":{"begin":55,"end":57},"obj":"19616983"},{"id":"26189817-18508266-2053334","span":{"begin":55,"end":57},"obj":"18508266"},{"id":"26189817-14757869-2053335","span":{"begin":96,"end":98},"obj":"14757869"},{"id":"26189817-23696415-2053336","span":{"begin":152,"end":154},"obj":"23696415"},{"id":"26189817-25058219-2053337","span":{"begin":395,"end":397},"obj":"25058219"},{"id":"26189817-24901367-2053337","span":{"begin":395,"end":397},"obj":"24901367"},{"id":"26189817-22499348-2053337","span":{"begin":395,"end":397},"obj":"22499348"},{"id":"26189817-25466870-2053337","span":{"begin":395,"end":397},"obj":"25466870"}],"text":"Having excluded mtDNA copy-number depletion by qPCR,26,27 mtDNA rearrangements by long-range PCR28 and mtDNA point mutations by direct Sanger sequencing29 in both subjects, we proceeded to undertake whole-exome sequencing (WES) to elucidate the molecular basis of the disease in individuals 73901 and 65205 by using previously described methodologies and bioinformatic filtering pipelines2,8,30,31 from which both affected individuals were found to harbor variants in TRMT5. Subject 73901 harbored compound heterozygous TRMT5 variants (GenBank: NM_020810.3): a c.312_315del (p.Ile105Serfs∗4) frameshift and a c.872G\u003eA (p.Arg291His) missense variant. Both were confirmed by Sanger sequencing in the affected individual, and all five healthy siblings are heterozygous carriers of the c.872G\u003eA (p. Arg291His) variant; parental samples were not available for carrier testing (Figure 1A). Subject 65205 harbored two heterozygous TRMT5 variants: the same c.312_315 del (p.Ile105Serfs∗4) frameshift variant identified in individual 73901 and a c.1156A\u003eG (p.Met386Val) missense variant. The presence of both variants was confirmed by Sanger sequencing. Carrier testing confirmed heterozygosity of the p.Met386Val variant in the mother. No material from the father was available for testing. The p.Arg291 and p.Met386 residues show absolute evolutionary conservation between human and yeast (Figure 1B). None of the identified variants are present in our combined exome database, which contains \u003e 5,700 samples. In the Exome Aggregation Consortium (ExAC) Browser, we found two of the three variants. The c.312_315del variant is reported with a minor-allele frequency (MAF) of 0.0009 (112/121,378 alleles), whereas the c.872G\u003eA variant was detected five times (MAF = 0.00004). Both missense changes are predicted to be deleterious according to PolyPhen-2 (p.Arg291His, probably damaging, score = 1.000 and p.Met386Val, probably damaging, score = 0.992) and SIFT (p.Arg291His, affects protein function, score = 0.00 and p.Met386Val, affects protein function, score = 0.00)."}