Loss of calpain-3 autocatalytic activity in LGMD2A patients with normal protein expression.

ABSTRACT: The diagnosis of limb girdle muscular dystrophy (LGMD) type 2A (due to mutations in the gene encoding for calpain-3) is currently based on protein analysis, but mutant patients with normal protein expression have also been identified. In this study we investigated 150 LGMD patients with normal calpain-3 protein expression, identified gene mutations by an allele-specific polymerase chain reaction test, and analyzed the mutant calpain-3 catalytic activity. Four different mutations were found in eight patients (5.5%): a frame-shifting deletion (550 A del) and three missense (R490Q, R489Q, R490W). Patients with normal calpain-3 protein expression on Western blot are a considerable proportion (20%) of our total LGMD2A population. While in control muscle the calpain-3 Ca(++)-dependent autocataly

SUBMITTER: Fanin M 

PROVIDER: S-EPMC1892408 | biostudies-literature | 2003 Nov

REPOSITORIES: biostudies-literature