Clinico-pathological diagnosis of Facioscapulohumeral Dystrophy in a 22-year-old Male

Background: Facioscapulohumeral dystrophy (FSHD) is a rare hereditary disease with a prevalence of 2.03–6.8 per 100,000 individuals. FSHD is the third most common type of muscular dystrophy after the Duchene muscular dystrophy and myotonic dystrophy. To the best of our knowledge, the current case report is the first to report probable FSHD case mainly diagnosed using clinico-pathological evidence from sub-Saharan Africa (SSA). Case Report: A 22-year-old right-handed male college student presented with progressive proximal muscular weakness associated with wasting. The weakness started from the bilateral facial muscles and progressively involved proximal upper and lower limbs muscles associated with scapular winging, waddling gait, and bilateral foot drops. His bulbar, sensory, autonomic, and cognitive systems were spared. Muscles EMG showed myopathic patterns and normal serum CK. Muscle biopsy from affected muscles showed variation in fiber size with groups of angular fibers, preserved fibers, and hypertrophic fibers with marked fibrosis and adipose tissue replacement with no apparent inflammation and necrosis which is consistent with pathological features of muscular dystrophy. Considering the clinical semiology, physical findings, EMG findings, and pathological findings diagnosis of FSHD of scapuloperoneal variant was made. The patient was managed with analgesics, nutritional advice, and ankle prosthesis for foot drops. Currently, the patient is in a similar condition with modest improvement in his musculoskeletal pain complaints. Conclusion: This case highlights the fact that a careful clinical evaluation with thorough utilization of diagnostic investigations available at our disposal may support the diagnosis of FSHD in resource-limited areas where the necessary genetic tests were not available. Keywords: facioscapulohumeral muscular dystrophy, dystrophy, clinico-pathology, sub-Saharan Africa

Development of an approach to knockdown of DUX4 gene by siRNA in myoblasts derived from patients with FSHD

Миодистрофия Ландузи-Дежерина (МЛД) - распространённое наследственное заболевание, вызываемое эктопической экспрессией гена DUX4 в мышечных клетках. Метод подавления экспрессии генов при помощи siРНК зарекомендовал себя как эффективный и безопасный способ генной терапии без вмешательства непосредственно в геном. В данной работе мы продемонстрировали возможность трансфекции миобластов человека целевыми siРНК без ущерба жизнеспособности и дальнейшей дифференцировке этих клеток в миотубы. Также мы показали различия в профиле экспрессии генов-мишеней DUX4 между миобластами, полученными от здоровых людей и от пациентов с МЛД. В дальнейшем эти данные могут помочь при разработке эффективных и специфичных siРНК для терапии МЛД. Facioscapulohumeral dystrophy (FSHD) is a common hereditary disease caused by ectopic expression of the DUX4 gene in muscle cells. The method of suppressing gene expression using siRNA has been shown to be an effective and safe method of gene therapy without interfering directly with the genome. In this work, we demonstrated the possibility of transfecting human myoblasts with targeted siRNAs without compromising the viability and further differentiation of these cells into myotubes. We also showed differences in the expression profile of DUX4 target genes between healthy and patient-derived myoblasts. In the future, these data can be used to develop effective and specific siRNAs for the treatment of FSHD.

Elucidation of the Genetic Cause in Dutch Limb Girdle Muscular Dystrophy Families: A 27-Year’s Journey

Background: A Dutch cohort of 105 carefully selected limb girdle muscular dystrophy patients from 68 families has been subject to genetic testing over the last 20 years. After subsequent targeted gene analysis around two thirds (45/68) of the families had received a genetic diagnosis in 2013. Objective: To describe the results of further genetic testing in the remaining undiagnosed limb-girdle muscular dystrophy (LGMD) families in this cohort. Methods: In the families of the cohort for whom no genetic diagnosis was established (n = 23) further testing using Sanger sequencing, next generation sequencing with gene panel analysis or whole-exome sequencing was performed. In one case DNA analysis for facioscapulohumeral dystrophy type 1 was carried out. Results: In eight families no additional genetic tests could be performed. In 12 of the remaining 15 families in which additional testing could be performed a genetic diagnosis was established: two LGMDR1 calpain3-related families with CAPN3 mutations, one LGMDR2 dysferlin-related family with DYSF mutations, three sarcoglycanopathy families (LGMDR3-5 α-, β- and γ-sarcoglycan-related) with SGCA/SGCB/SGCG mutations, one LGMDR8 TRIM 32-related family with TRIM32 mutations, two LGMDR19 GMPPB-related families with GMPPB mutations, one family with MICU1-related myopathy, one family with FLNC-related myopathy and one family with facioscapulohumeral dystrophy type 1. At this moment a genetic diagnosis has been made in 57 of the 60 families of which DNA was available (95%). Conclusion: A genetic diagnosis is obtained in 95% of the families of the original Dutch LGMD cohort of which DNA was available.