Glycyl-tRNA synthetase (GARS), which encodes the enzyme responsible for charging 
tRNA(Gly) with glycine in both the cytoplasm and mitochondria, is implicated to 
Charcot-Marie-Tooth disease 2D (CMT2D) and distal hereditary motor neuropathy 
type V (dHMN-V). We performed whole exome sequencing (WES) to identify the 
genetic defects in the two dHMN families. WES revealed several decades of 
non-synonymous variants in the CMT and aminoacyl-tRNA synthetase genes. The 
subsequent capillary sequencing for family members and controls revealed two 
novel causative mutations, c.598G>A (D200N) and c.794C>T (S265F), in the GARS 
gene in each dHMN family. Both mutations were cosegregated with affected 
individuals in each family, and were not found in the 200 controls. The mutation 
sites were well conserved between the different species and in silico analysis 
predicted that both mutations may affect protein function. Therefore, we believe 
that these two novel GARS mutations are the underlying causes of the dHMN 
phenotype.