Case Series of Autosomal Recessive Limb-girdle Muscular Dystrophies with Atypical Inheritance Pattern



Poster Number: 193


Khaled Albazli, MD, Georgetown University Hospital, Nicholas Streicher, MD, Medstar Georgetown University Hospital, Shreya Gandhy, DO, Medstar Georgetown University Hospital, Shakti Nayar, MD, Georgetown University Hospital

Introduction: Limb-girdle muscular dystrophies (LGMD) are a group of a genetically heterogeneous muscle disorders characterized by progressive weakness and atrophy predominantly affecting proximal limb muscles. There are a growing number of LGMDs with increasing heterogeneity recently reported. The gold standard for diagnosis is muscle biopsy and detection of causative mutations in the associated gene. Strict autosomal recessive inheritance is often assumed, with recessive loss-of-function mutations on both alleles, typically resulting in a LGMD phenotype. However, single allelic mutation, although atypical, can present with phenotypical muscle disease consistent with LGMD. Method: Our retrospective analysis included patients diagnosed in muscular dystrophy association (MDA) clinic with potential LGMD. Potential cases were identified by ICD-10 codes G71.0 and G71.1. Out of ## of phenotypic LGMD patients reviewed, clinical and genetic characteristics of 5 cases with atypical one allele mutation in known autosomal recessive LGMD genes was reported. Conclusion: Based on the results of our data and the literature we reviewed, few cases with one allele mutation can present with LGMD phenotype. Therefore, comprehensive mRNA and/or cDNA analysis of variants and splicing is critical to diagnose and to understand the pathogenesis of this heterogenous disease