Mutation analysis and evaluation of the cardiac localization of TMEM43 in arrhythmogenic right ventricular cardiomyopathy

作者：Christensen A H^*; Andersen C B; Tybjaerg Hansen A; Haunso S; Svendsen J H

来源：Clinical Genetics, 2011, 80(3): 256-264.

DOI：10.1111/j.1399-0004.2011.01623.x

• ARVC
• genetics
• immunohistochemistry
• TMEM43

A single report has associated mutations in TMEM43 (LUMA) with a distinctive form of arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed at performing mutational analysis of the gene and characterizing the associated immunohistochemical features. Sixty-five unrelated patients (55 fulfilling Task Force criteria and 10 borderline cases) were screened for mutations in TMEM43. Immunohistochemistry with anti-TMEM43, anti-plakoglobin, anti-plakophilin-2, anti-connexin-43, and anti-emerin antibodies was performed on myocardium from TMEM43-positive patients (n = 3) and healthy controls (n = 3). The genetic screening identified heterozygous variants in two families: one reported mutation (c. 1073C>T; in two related patients) and one novel variant (c. 705+7G>A; in one patient) of unknown significance. All three patients fulfilled Task Force criteria and did not carry mutations in any other ARVC-related gene. Immunostaining with TMEM43 antibody showed intense staining of the sarcolemma. The signal level was reduced in all the three TMEM43-positive patients. Immunostaining with plakoglobin-specific antibody also showed reduced signal levels in the three carriers. All patients displayed a similar immunoreactive signal for plakophilin-2, connexin-43, and emerin. In conclusion, two TMEM43 sequence variants were identified in this Danish ARVC cohort. Evaluation of the expression of TMEM43 showed a unique cardiac localization. The immunoreactive signal for the desmosomal protein plakoglobin was reduced in mutation carriers. The TMEM43 gene underlies a distinctive form of ARVC which may share a final common pathway with desmosome-associated ARVC.

• 出版日期2011-9