title: Spectrum of LDLR gene mutations, including a novel mutation causing familial hypercholesterolaemia, in North-western Greece.
abstract: BACKGROUND
  Familial Hypercholesterolaemia (FH) is a clinical syndrome characterised by elevated serum low-density lipoprotein (LDL) cholesterol, by tendon xanthomata and clinical manifestations of ischaemic heart disease in early life. Typically, it results from mutations in the low-density lipoprotein receptor (LDLR) gene. Furthermore, there are 3 additional genetic disorders that cause clinical syndromes that mimic FH. These are: 1) familial ligand-defective apolipoprotein (apo)-B (FLDH), 2) familial hypercholesterolaemia type 3 (FH3) and 3) autosomal recessive hypercholesterolaemia (ARH). The aim of this study was to elaborate the impact of the above genetic disorders in Greek patients with a clinical diagnosis of FH.
  
  
  METHODS
  In this study, we assessed the contribution of the LDLR, Apo B, ARH and PCSK9 genes in the expression of FH in North-western Greece. Two hundred and fifty-four (254) probands with a clinical diagnosis of FH were included in the study.
  
  
  RESULTS
  One hundred and sixty-nine (169) patients had one of the following LDLR gene mutations: 81T>G, 1775G>A, 517T>C, 858C>A, 1352T>C, 1285G>A, 761A>C, 1195G>A, 1646G>A and a deletion mutation g.387-410del24 in exon 4. We sequenced the Apo B, ARH and PCSK9 genes in 40, randomly selected patients, from the 85 patients with no identified LDLR gene defects. In these 40, randomly selected patients, with the exception of benign single nucleotide polymorphisms, no functional mutations were identified for all the above mentioned sequenced genes.
  
  
  CONCLUSIONS
  Our results reveal substantial genetic heterogeneity for FH in North-western Greece with at least ten LDLR gene mutations present in the study population. One of these mutations although quite rare is reported here for the first time in the scientific literature. The detection of these mutations is important as they may be used to design multiplex detection assays for large scale population screening programmes to facilitate primary and secondary prevention of cardiovascular disease in the region. Finally, ARH, Apo B and PCSK9 gene defects were excluded from causing FH in a subgroup of the study population indicating that other yet unrecognized genes may be involved in causing the clinical feature of FH, and/or that large scale deletions/duplications evaded the applied mutation detection techniques of this study.
authors.affiliation: Department of Internal medicine, Medical School, University of Ioannina, Ioannina, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Diakou
authors.forename: George
authors.initials: G
authors.lastname: Miltiadous
authors.forename: Stavroulla L
authors.initials: SL
authors.lastname: Xenophontos
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Manoli
authors.forename: Marios A
authors.initials: MA
authors.lastname: Cariolou
authors.forename: Moses
authors.initials: M
authors.lastname: Elisaf
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006115:Greece / Q000453:epidemiology; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015995:Prevalence; D011379:Prognosis; D011973:Receptors, LDL / Q000097:blood / Q000235:genetics*; D055815:Young Adult
chemical_list: D011973:Receptors, LDL; D004247:DNA