Mashhad University of Medical Sciences (MUMS) Reviews in Clinical Medicine Rev Clin Med 2021; Vol 8 (No 1) Published by: Mashhad University of Medical Sciences (http://rcm.mums.ac.ir) 35 Clinical Research Development Center Ghaem Hospital *Corresponding author: Ariane Sadr Nabavi. Department of Medical Genetics and Molecular Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. E-mail: sadrnabavia@mums.ac.ir This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tel: 989155570305 A review of Genetic Etiology and Emerging Molecular Therapies for FSHD in Preclinical Studies Mohammad Reza Seyyed Taghia(MSc Student) 1 ,Reza Jafarzadeh Esfehani (Ph.D) 1,4,5 , Reza Boostani (MD) 2 , Mohammad Shariati (MD) 2,3 , Ariane Sadr Nabavi (Ph.D) 1,2* 1 Department of Medical Genetics and Molecular Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. 2 Department of Neurology, Mashhad University of Medical Sciences, Mashhad, Iran. 3 Stem Cells and Regeneratiive Medicine Department, Academic Center for Education, Culture and Research (ACECR)- Khorasan Razavi, Mashhad, Iran. 4 Students Research Committee, Baqiyatalahl University of Medical Sciences, Tehran, Iran. 5 Blood Borne Infections Research Center, Academic Center for Education, Culture and Research (ACECR)- Khorasan Razavi, Mashhad, Iran. Introduction Facioscapulohumeral muscular dystrophy (FSHD) is the third most common musculoskele- tal disorder after dystrophinopathy and myoton- ic dystrophy (1,2). Before the widespread use of genetic diagnostic techniques, the prevalence of FSHD was reported to be as high as 5 cases per 100,000 individuals, which is now reached up to 7 cases per 100,000 people (3). FSHD is now con- sidered a genetic disorder with variable symptoms and a complex etiology (4).Among these variable clinical symptoms, weakness of the facial mus- cles leading to the loss of the ability to express emotions is a common clinical finding making it difficult to drink or pronounce certain words (5,6). Muscle weakness can also affect the eye, making it difficult to close eyes properly, result- ing in conditions including dry eye and keratop- athy (7,8). The weakness of the scapulae mus- cles is also present. The weakness of the scapula muscles leads to the winging and overriding ARTICLE INFO ABSTRACT Article type Review article Article history Received: 15 Feb 2021 Revised: 10 March 2021 Accepted: 20 Apr 2021 Keywords Facioscapulohumeral muscular dystrophy Genetic therapy Small interfering RNA Facioscapulohumeral muscular dystrophy is one of the most common musculoskeletal diseases with a considerable burden. Most of the affected individuals experience muscle weakness as the common muscular symptom. Despite the underlying genetic mechanism which is extensively studied, curative treatment is not available for patients with facioscapulohumeral muscular dystrophy, and only supportive care is considered as the treatment of choice. Recently, several studies addressed the treatment of facioscapulohumeral muscular dystrophy by genetic engineering strategies, most of which indicate the effectiveness of different types of small interfering ribonucleic acids. However, these studies are still in the preclinical phase and it seems that there is a long way ahead of curing facioscapulohumeral muscular dystrophy despite recent advances in the field of genetic engineering. This study aimed to review the underlying genetic mechanism of Facioscapulohumeral muscular dystrophy alongside providing the latest preclinical studies related to the treatment of this disease. Please cite this paper as: Seyyed Taghia MR, Jafarzadeh Esfehani R, Boostani R, Shariati M, Sadr Nabavi A. A Review of Genetic Etiology and Emerging Molecular Therapies for FSHD in Preclinical Studies. Rev Clin Med. 2021;8(1):35-40.