Targeted gene under study:

EPRS1 (OMIM 138295, ORPHA 617951)


EPRS1 is a bifunctional aminoacyl tRNA synthetase responsible for loading proline and glutamate onto their respective tRNAs. Biallelic pathogenic variants in EPRS1 have been shown to cause an ultra-rare hypomeylinating leukodystrophy previously reported in 4 patients and a milder neurodevelopmental phenotype associated with epilepsy and deafness in 1 patient.

In this project, we aim to characterize the phenotypic spectrum of EPRS1-related disorder and identify possible genotype-phenotype correlations. We have collected a patient cohort of approximately 22 patients with biallelic variants in EPRS1 thus far and are looking to expand this cohort further.

Coordinating clinicians

Dr. Genevieve Bernard –

Alexandra Chapleau –

Dr. Reza Maroofian –

Stephanie Efthymiou –


Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Canada

Department of Neuromuscular Disorders, UCL Institute of Neurology, Queen Square, London, UK

Specific requirements beyond clinical data and genotype data sharing:

1- Re-analysis of DNA samples: No

2- Resampling of patients: No 

3- Linked to a translational/basic research project: Yes