A donor splice site mutation in CISD2 generates multiple truncated, non-functional isoforms in Wolfram syndrome type 2 patients

BMC Medical Genetics

Research Article

Monica Cattaneo¹  Lucia La Sala¹  Annibale Alessandro Puca²  Antonio Ceriello³  Orsetta Zuffardi⁴  Edoardo Errichiello⁴  Stefano Genovese⁵  Maurizio Rondinelli⁵ 

[1]Cardiovascular Research Unit, IRCCS MultiMedica, Via G. Fantoli 16/15, 20138, Milan, Italy

[2]Cardiovascular Research Unit, IRCCS MultiMedica, Via G. Fantoli 16/15, 20138, Milan, Italy

[3]Department of Medicine and Surgery, University of Salerno, 84084, Salerno, Italy

[4]Cardiovascular Research Unit, IRCCS MultiMedica, Via G. Fantoli 16/15, 20138, Milan, Italy

[5]Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain

[6]Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy

[7]Diabetes Endocrine and Metabolic Diseases Unit, IRCCS MultiMedica, 20099 Sesto San Giovanni, Milan, Italy

[8]IRCCS Centro Cardiologico Monzino Diabetes, Endocrine and Metabolic Diseases Unit, 20138, Milan, Italy

关键词: CISD2;    Wolfram syndrome type 2;    mRNA splicing;    Non functional isoforms;    Nonsense-mediated mRNA decay;   

DOI  :  10.1186/s12881-017-0508-2

 received in 2017-06-14, accepted in 2017-11-29,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundMutations in the gene that encodes CDGSH iron sulfur domain 2 (CISD2) are causative of Wolfram syndrome type 2 (WFS2), a rare autosomal recessive neurodegenerative disorder mainly characterized by diabetes mellitus, optic atrophy, peptic ulcer bleeding and defective platelet aggregation. Four mutations in the CISD2 gene have been reported. Among these mutations, the homozygous c.103 + 1G > A substitution was identified in the donor splice site of intron 1 in two Italian sisters and was predicted to cause a exon 1 to be skipped.MethodsHere, we employed molecular assays to characterize the c.103 + 1G > A mutation using the patient’s peripheral blood mononuclear cells (PBMCs). 5′-RACE coupled with RT-PCR were used to analyse the effect of the c.103 + 1G > A mutation on mRNA splicing. Western blot analysis was used to analyse the consequences of the CISD2 mutation on the encoded protein.ResultsWe demonstrated that the c.103 + 1G > A mutation functionally impaired mRNA splicing, producing multiple splice variants characterized by the whole or partial absence of exon 1, which introduced amino acid changes and a premature stop. The affected mRNAs resulted in either predicted targets for nonsense mRNA decay (NMD) or non-functional isoforms.ConclusionsWe concluded that the c.103 + 1G > A mutation resulted in the loss of functional CISD2 protein in the two Italian WFS2 patients.

【 授权许可】

CC BY   
© The Author(s). 2017