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A Recurrent loss‐of‐function alanyl‐tRNA synthetase ( AARS ) mutation in patients with charcot‐marie‐tooth disease type 2N (CMT2N)
Author(s) -
McLaughlin Heather M.,
Sakaguchi Reiko,
Giblin William,
Wilson Thomas E.,
Biesecker Leslie,
Lupski James R.,
Talbot Kevin,
Vance Jeffery M.,
Züchner Stephan,
Lee YiChung,
Kennerson Marina,
Hou YaMing,
Nicholson Garth,
Antonellis Anthony
Publication year - 2012
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.21635
Subject(s) - biology , aminoacyl trna synthetase , genetics , mutation , transfer rna , nonsense mutation , gene , microbiology and biotechnology , rna , missense mutation
Charcot‐Marie‐Tooth (CMT) disease comprises a heterogeneous group of peripheral neuropathies characterized by muscle weakness and wasting, and impaired sensation in the extremities. Four genes encoding an aminoacyl‐tRNA synthetase (ARS) have been implicated in CMT disease. ARSs are ubiquitously expressed, essential enzymes that ligate amino acids to cognate tRNA molecules. Recently, a p.Arg329His variant in the alanyl‐tRNA synthetase ( AARS ) gene was found to segregate with dominant axonal CMT type 2N (CMT2N) in two French families; however, the functional consequence of this mutation has not been determined. To investigate the role of AARS in CMT, we performed a mutation screen of the AARS gene in patients with peripheral neuropathy. Our results showed that p.Arg329His AARS also segregated with CMT disease in a large Australian family. Aminoacylation and yeast viability assays showed that p.Arg329His AARS severely reduces enzyme activity. Genotyping analysis indicated that this mutation arose on three distinct haplotypes, and the results of bisulfite sequencing suggested that methylation‐mediated deamination of a CpG dinucleotide gives rise to the recurrent p.Arg329His AARS mutation. Together, our data suggest that impaired tRNA charging plays a role in the molecular pathology of CMT2N, and that patients with CMT should be directly tested for the p.Arg329His AARS mutation. Hum Mutat 33:244–253, 2012. © 2011 Wiley Periodicals, Inc.