Evidence that the mitochondrial leucyl tRNA synthetase (LARS2) gene represents a novel type 2 diabetes susceptibility gene.
Previously, we have shown that a mutation in the mitochondrial DNA-encoded tRNA(Leu(UUR)) gene is associated with type 2 diabetes. One of the consequences of this mutation is a reduced aminoacylation of tRNA(Leu(UUR)). In this study, we have examined whether variants in the leucyl tRNA synthetase gene (LARS2), involved in aminoacylation of tRNA(Leu(UUR)), associate with type 2 diabetes. Direct sequencing of LARS2 cDNA from 25 type 2 diabetic subjects revealed eight single nucleotide polymorphisms. Two of the variants were examined in 7,836 subjects from four independent populations in the Netherlands and Denmark. A -109 g/a variant was not associated with type 2 diabetes. Allele frequencies for the other variant, H324Q, were 3.5% in type 2 diabetic and 2.7% in control subjects, respectively. The common odds ratio across all four studies was 1.40 (95% CI 1.12-1.76), P = 0.004. There were no significant differences in clinical variables between carriers and noncarriers. In this study, we provide evidence that the LARS2 gene may represent a novel type 2 diabetes susceptibility gene. The mechanism by which the H324Q variant enhances type 2 diabetes risk needs to be further established. This is the first report of association between an aminoacyl tRNA synthetase gene and disease. Our results further highlight the important role of mitochondria in glucose homeostasis.
't Hart
Leen M
LM
Leiden University Medical Center, Department of Molecular Cell Biology, Wassenaarseweg 72, 2333 AL Leiden, Netherlands. l.m.t_hart@lumc.nl
Hansen
Torben
T
Rietveld
Ingrid
I
Dekker
Jacqueline M
JM
Nijpels
Giel
G
Janssen
George M C
GM
Arp
Pascal A
PA
Uitterlinden
André G
AG
Jørgensen
Torben
T
Borch-Johnsen
Knut
K
Pols
Huibert A P
HA
Pedersen
Oluf
O
van Duijn
Cornelia M
CM
Heine
Robert J
RJ
Maassen
J Antonie
JA
D000368:Aged; D002874:Chromosome Mapping; D004272:DNA, Mitochondrial; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007935:Leucine-tRNA Ligase / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020641:Polymorphism, Single Nucleotide
D004272:DNA, Mitochondrial; D007935:Leucine-tRNA Ligase