title: CAPN3 mRNA processing alteration caused by splicing mutation associated with novel genomic rearrangement of Alu elements.
abstract: Recessive mutations of CAPN3 gene are reported to be responsible for limb girdle muscular dystrophy type 2A (LGMD2A). In all, 15-25% of intronic nucleotide changes identified in this gene were investigated by in silico analysis, but occasionally supported by experimental data or reported in some cases as a polymorphism. We report here genetic and transcriptional analyses in three Tunisian patients belonging to the same consanguineous family sharing the same mutation c.1194-9 A>G and Alu repeats insertion in intron 7 of CAPN3 gene. Reverse transcriptase-PCR experiments performed on total RNA from the patient's muscle biopsy showed retention of the eight last nucleotides of intron 9 in the CAPN3 transcript lacking the first seven exons. Our results provide evidence regarding the potential involvement of Alu elements in aberrant processing of pre-mRNA owing to the disruption of pre-existing intronic splicing regulatory elements. We also demonstrated variable mRNA alternative splicing among tissues and between LGMD2A patients. A deep intronic variation and rearrangement have been reported in the literature as causing genetic diseases in humans. However, this is the first report on a potential pathogenic CAPN3 gene mutation resulting from an Alu insertion.
authors.affiliation: Laboratoire de Génétique Moléculaire Humaine, Université de Sfax, Sfax, Tunisia. ikhlasshadj@gmail.com
authors.forename: Ikhlass Hadj
authors.initials: IH
authors.lastname: Salem
authors.forename: Ines
authors.initials: I
authors.lastname: Hsairi
authors.forename: Najla
authors.initials: N
authors.lastname: Mezghani
authors.forename: Houda
authors.initials: H
authors.lastname: Kenoun
authors.forename: Chahnez
authors.initials: C
authors.lastname: Triki
authors.forename: Faiza
authors.initials: F
authors.lastname: Fakhfakh
mesh_terms: D000293:Adolescent; D017398:Alternative Splicing; D020087:Alu Elements; D001483:Base Sequence; D002154:Calpain / Q000235:genetics* / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D003241:Consanguinity; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics*; D016254:Mutagenesis, Insertional; D017354:Point Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D009124:Muscle Proteins; D012333:RNA, Messenger; C105884:CAPN3 protein, human; D002154:Calpain