New Mouse Model Provides Insight Into Genetic Neurological Disorders

Scientists have created a mouse to help understand human neuronal diseases that impair a patient's ability to feel and to move their arms and legs. By strategically altering a protein-making molecule, a mouse was made with symptoms similar to the nervous system diseases, Charcot-Marie-Tooth (CMT) and hereditary motor neuropathy (HMN). In CMT and HMN, neurons that signal and maintain muscle cells become defective, which causes weakening and loss of muscle that is significant enough in some cases to lead to death. The symptoms become progressively worse over time and no effective treatments or cures exist for these diseases. Researchers came together from the University College London (UCL), the Medical Research Centre (MRC) Harwell, the University of Oxford, and the University of London in England, Vrije University in The Netherlands and Jackson Laboratories in the US to make a genetic change in mice that has been associated with CMT and HMN diseases in people.

Neurosensory diseases are difficult to model in mice because they involve symptoms that are complex and diverse. These diseases are passed from parents to their children but the genetic causes identified are often lethal when transferred to a mouse. The lack of animal models slows progress in understanding and treating the diseases.

The researchers made a mutation in a protein, which is part of the protein building machinery, called glycyl-tRNA synthetase (GARS). As described in their study in Disease Models & Mechanisms (DMM),

When the researchers made the same mutation in two different breeds of mice it caused two distinguishable sets of symptoms, demonstrating that the genetic background influences the effects of the GARS gene mutation. This variability in the mouse disease symptoms is also seen in humans, and may help shed light on how CMT and HMN differently affect individual patients' symptoms.

The report titled "An ENU-induced mutation in mouse glycyl tRNA synthetase (Gars) causes peripheral sensory and motor phenotypes creating a model of Charcot-Marie-Tooth type 2D peripheral neuropathy" was written by Francesca Achilli, Virginie Bros Facer, Hazel Williams, Gareth Banks, Mona AlQatari, Ruth Chia, Michael Groves, Sebastian Brandner, Martin Koltzenburg, Linda Greensmith, and Elizabeth M.C. Fisher at the University College London (UCL), Valter Tucci, Rachel Kendall and Patrick Nolan at the Medical Research Centre (MRC) Harwell, Carole Nickols and Joanne Martin at Queen Mary University of London, Kevin Seburn and Robert Burgess at Jackson Laboratories, Muhammed Cader and Kevin Talbot at the University of Oxford, and Jan van Minnen at Vrije University. The study is published in the June/July issue of the new research journal, Disease Models & Mechanisms (DMM), published by The Company of Biologists, a non-profit based in Cambridge, UK.