Screening for subtelomeric rearrangements using automated fluorescent genotyping of microsatellite markers: a Lebanese study

A naturally occurring human minidysferlin protein repairs sarcolemmal lesions in a mouse model of dysferlinopathy

Dysferlinopathies are autosomal recessive, progressive muscle dystrophies caused by mutations in DYSF, leading to a loss or a severe reduction of dysferlin, a key protein in sarcolemmal repair. Currently, no etiological treatment is available for patients affected with dysferlinopathy. As for other muscular dystrophies, gene therapy approaches based on recombinant adeno-associated virus (rAAV) vectors are promising options. However, because dysferlin messenger RNA is far above the natural packaging size of rAAV, full-length dysferlin gene transfer would be problematic. In a patient presenting with a late-onset moderate dysferlinopathy, we identified a large homozygous deletion, leading to the production of a natural "minidysferlin" protein. Using rAAV-mediated gene transfer into muscle, we demonstrated targeting of the minidysferlin to the muscle membrane and efficient repair of sarcolemmal lesions in a mouse model of dysferlinopathy. Thus, as previously demonstrated in the case of dystrophin, a deletion mutant of the dysferlin gene is also functional, suggesting that dysferlin's structure is modular. This minidysferlin protein could be used as part of a therapeutic strategy for patients affected with dysferlinopathies.

A novel competitive fluorescent multiplex STR polymorphism assay for rapid, reliable and single-tube screening of 22q11.2 copy-number aberrations

Copy-number aberrations of the 22q11.2 region can lead to varied resulting and complex phenotypes. Routine screening for these common constitutional chromosomal abnormalities requires powerful tools. A competitive fluorescent multiplex STR polymorphism assay (CFMSA) was built for detecting these aberrations. With the introduction of an internal reference and distinguishable STR polymorphism markers, this competitive fluorescent multiplex STR polymorphism assay provides complementary information about polymorphism and gene dosage in one tube simultaneously, thereby enhancing the assay sensitivity. It was first tested in 110 normal controls, and was proven to have highly polymorphic and reliable gene dosage information. Then, 476 subjects with congenital heart defect were screened according to the testing strategy of the American Heart Association, and 17 deletions and 1 duplication of 22q11.2 were correctly identified. It is expected that this assay will serve as a cost-effective alternative to existing assays for routine, large-scale screening in all at-risk individuals with either deletion or duplication in 22q11.2.