G.P.44 Spectrum of mutations identified in the cohort of Czech LGMD patients

Abstract

Limb girdle muscular dystrophies (LGMDs) represent a group of clinically and genetically heterogeneous disorders predominantly affecting shoulder and pelvic girdles. To date, 15 forms (2A-N) of autosomal recessive (AR) and eight forms (1A-H) of autosomal dominant LGMDs have been described. LGMD2A is the most frequent form of LGMD in many European countries, and is caused by mutations in the CAPN3 gene that encodes a muscle specific protease, calpain-3. Besides LGMD2A, we perform molecular genetic diagnostics of LGMD2I, LGMD2D, and LGMD2L caused by mutations in genes encoding fukutin-related protein (FKRP), alpha-sarcoglycan (SGCA) and anoctamin-5 (ANO5). Based on the results of clinical assessment and histopathological examination of muscle biopsies (including protein analysis using immunohistochemistry and immunoblotting), the mutational analysis of the CAPN3, FKRP, SGCA, and ANO5 genes was performed at the mRNA level (using reverse transcription-PCR-direct sequencing) and/or at the DNA level (using PCR-direct sequencing) in a cohort of Czech patients with a preliminary diagnosis of LGMD. In total, we screened 230 unrelated patients and mutations associated with the disease were determined in 70 of them (30.4%). Mutations in the CAPN3 gene were found in 55 patients, and LGMD2A was confirmed to represent the most frequent AR LGMD in the Czech Republic. The homozygous occurence of the most common mutation in the FKRP gene (p.Leu276Ile) associated with LGMD2I was determined in eight patients. Mutations in the SGCA and ANO5 genes were detected in 5 LGMD2D and 2 LGMD2L patients, respectively. This work was funded by the project “CEITEC – Central European Institute of Technology” (CZ.1.05/1.1.00/02.0068).