Naimeh ahangari - Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran- Next Generation Genetic Polyclinic, Mashhad, Iran
Mohammad Doosti - Next Generation Genetic Polyclinic, Mashhad, Iran
Sima Shahrokhzadeh - Next Generation Genetic Polyclinic, Mashhad, Iran
Farah Ashrafzadeh - Department of Pediatrics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Introduction: Leukodystrophies comprise a clinically and genetically heterogeneous group of progressivehereditary neurological disorders mainly affecting the myelin in the central nervous system. Here, we present afamily with leukodystrophy followed by molecular genetic evaluation.Methods: A nine years old boy with peripheral neuropathy, polycyctic kidney and Precocious puberty, referredfor genetic counselling. EMG showed axonal neuropathy which has suggested demyelinating type. Parents werefirst cousin with no history of other patient in their first and second degrees’ relatives. Genomic DNA wasevaluated through whole exome sequencing followed by bioinformatics analysis of data. Parents and healthychild were examined for the candidate gene variant.Results: One homozygote variant c.851+1G> A on gene GAN has been detected. The frequencies of this variantin normal population are very low. It has been reported as pathogenic and predicted to be damaging by severalonline prediction tools. GAN- related giant axonal neuropathy is inherited in an autosomal recessive manner.Parents and other healthy child were heterozygote for this variant.Conclusion: This case demonstrates that this major developmental error can be diagnosed with new molecularmethod such as whole exome sequencing along with comprehensive clinical examination.

leukodystrophy, Neurogenetics, Whole Exome Sequencing