title: LDLR gene synonymous mutation c.1813C>T results in mRNA splicing variation in a kindred with familial hypercholesterolaemia.
abstract: Familial hypercholesterolaemia, one of the most common inherited diseases in the general population, is associated with mutations in at least three different genes including the low density lipoprotein receptor (LDLR), apolipoprotein B (APOB) and protein convertase subtilisin/kexin type 9 (PCSK9) genes. In this report, we describe an unclassified DNA variant (c.1813C>T; p.Leu605Leu) within exon 12 of the LDLR gene in a kindred in which familial hypercholesterolaemia is associated with c.1813C>T heterozygosity. In silico analysis suggested that c.1813C>T might affect splicing of the LDLR gene by creating a cryptic donor splice site, which was confirmed by RT-PCR coupled with cDNA sequencing, to result in the loss of 34 base pairs in the coding sequence. The latter truncated mRNA is predicted to generate a frameshift leading to a premature stop at codon 652 and early termination of the low density lipoprotein receptor polypeptide chain, and thus provides a molecular basis for the hypercholesterolaemic phenotype. This case report highlights the emerging utility of RNA studies for the molecular diagnosis of familial hypercholesterolaemia in patients with potential mRNA splicing variants.
authors.affiliation: Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, Edinburgh, UK Department of Pathology and Laboratory Medicine, KK Women's and Children's Hospital, Singapore, Singapore.
authors.forename: Clement K M
authors.initials: CK
authors.lastname: Ho
authors.affiliation: Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: Fathel Rahman
authors.initials: FR
authors.lastname: Musa
authors.affiliation: Department of Medical Genetics, Aberdeen Royal Infirmary, Aberdeen, UK.
authors.forename: Christine
authors.initials: C
authors.lastname: Bell
authors.affiliation: Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, Edinburgh, UK Simon.Walker@nhslothian.scot.nhs.uk.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Walker
mesh_terms: D000328:Adult; D001483:Base Sequence; D005260:Female; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000235:genetics*; D008297:Male; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011973:Receptors, LDL / Q000235:genetics*; D000069456:Silent Mutation
chemical_list: D012333:RNA, Messenger; D011973:Receptors, LDL
keywords: Hypercholesterolaemia; low density lipoprotein receptor; mRNA splicing