A mutation in myotilin causes spheroid body myopathy

Autor: B. Azzarelli, Ruben Vidal, Hans-Hilmar Goebel, L. J. Cushman, Martin R. Farlow, Tatiana Foroud, Nathan Pankratz, H. Horak, Michael W. Pauciulo, Leticia Miravalle, William C. Nichols, A. P. Batchman
Rok vydání: 2005
Předmět:
Zdroj: Neurology. 65:1936-1940
ISSN: 1526-632X
0028-3878
DOI: 10.1212/01.wnl.0000188872.28149.9a
Popis: Background: Spheroid body myopathy (SBM) is a rare, autosomal dominant, neuromuscular disorder, which has only been previously reported in a single large kindred. Identification of the mutated gene in this disorder may provide insight regarding abnormal neuromuscular function. Methods: The authors completed a detailed clinical evaluation on an extensive kindred diagnosed with SBM. Genome-wide linkage analysis was performed to localize the disease gene to a specific chromosomal region. Further marker genotyping and screening of a positional, functional candidate gene were completed to detect the disease-causing mutation. Pathologic analysis of muscle biopsy was performed on three individuals. Biochemical studies were performed on one muscle biopsy specimen from an affected individual. Results: Linkage to chromosome 5q23-5q31 was detected with a lod score of 2.9. Genotyping of additional markers in a larger sample of family members produced a maximum lod score of 6.1 and narrowed the critical interval to 12.2 cM. Screening of the candidate gene titin immunoglobulin domain protein ( TTID , also known as MYOT ) detected a cytosine-to-thymine mutation in exon 2 of all clinically affected family members. Similar pathologic changes were present in all muscle biopsy specimens. Immunohistologic and biochemical analysis revealed that the TTID protein, also known as myotilin, is a component of the insoluble protein aggregate. Conclusions: A novel mutation in the TTID gene results in the clinical and pathologic phenotype termed “spheroid body myopathy.” Mutations in this gene also cause limb-girdle muscular dystrophy 1A and are associated with myofibrillar myopathy.
Databáze: OpenAIRE