Song D, Li X, Wei W, Liu X, Wu L, Xiong H. Microhomology-Mediated Nonhomologous End Joining Caused Rearrangement of
EMD and
FLNA in Emery-Dreifuss Muscular Dystrophy.
Front Genet 2022;
12:786294. [PMID:
34976019 PMCID:
PMC8719250 DOI:
10.3389/fgene.2021.786294]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/15/2021] [Indexed: 12/01/2022] Open
Abstract
Background: Emery–Dreifuss muscular dystrophy (EDMD) is a rare disease characterized by early joint contractures, slowly progressive muscular dystrophy, and cardiac involvement, which includes arrhythmia, dilated cardiomyopathy, hypertrophic cardiomyopathy, heart failure, and sudden death.
Methods: Clinical data of the proband and family members were collected. The next-generation sequencing technology was used to analyze the pathogenic variants and copy number variations. Polymerase chain reaction was used to sequence the breakpoints of gene locus rearrangements.
Results: Here, we report two siblings with EDMD in a family. The proband, a 17-year-old boy, manifested a dilated right heart, bradycardia, mild muscle weakness, and joint contractures. His younger brother only showed a mild bowing limitation with elevated creatine kinase. Next-generation sequencing revealed the complete deletion of EMD and a rearrangement in FLNA (exon29_48dup) in these two patients. The EMD deletion and partial FLNA duplication were accompanied by a 5 bp overlap (GTCCC) on the background of the FLNA-EMD inversion. These findings support the pathogenic mechanism of microhomology-mediated nonhomologous end joining.
Conclusion: We report two siblings with complete EMD deletion and FLNA duplication in a family. A microhomology-mediated nonhomologous end joining event involving EMD and FLNA acts as the underlying mechanism.
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