G to C transversion at a splice acceptor site causes exon skipping in the cystatin B gene.
Several mutations have been described in the proteinase inhibitor cystatin B gene from individuals affected with progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1). One of these mutations, a 1925G-->C transition at the 3'-splice acceptor site of the intron 1, was postulated to lead to inappropriate splicing of a primary transcript of the cystatin B gene in EPM1 patients. In an effort to understand the expression of the 1925G-->C mutation, the sequence of cystatin B mRNA transcripts from lymphoblastoid cell lines of heterozygous patients carrying the mutation were analyzed. RT-PCR of total mRNA showed two main products: the apparently normal transcript and an aberrant, 102 bp shorter transcript. Direct PCR sequencing showed that the aberrant transcript is a consequence of exon 2 skipping.
Bespalova
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Mental Health Research Institute, University of Michigan, Ann Arbor 48109-0720, USA.
Pranzatelli
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Burmeister
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D002460:Cell Line; D055313:Cystatin B; D015891:Cystatins / Q000235:genetics*; D004252:DNA Mutational Analysis; D004831:Epilepsies, Myoclonic / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005796:Genes / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D008214:Lymphocytes; D017354:Point Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*
C524994:CSTB protein, human; D015891:Cystatins; D012333:RNA, Messenger; D055313:Cystatin B