Identification and functional characterization of LDLR mutations in familial hypercholesterolemia patients from Southern Italy

Atherosclerosis. 2010 Jun;210(2):493-6. doi: 10.1016/j.atherosclerosis.2009.11.051. Epub 2009 Dec 5.

Abstract

Objective: Autosomal dominant hypercholesterolemias are due to defects in the LDL receptor (LDLR) gene, in the apolipoprotein B-100 gene or in the proprotein convertase subtilisin/kexin type 9 gene. The aim of this study was to identify and functionally characterize mutations in the LDLR gene that account for most cases of familial hypercholesterolemia (FH).

Methods: We enrolled 56 unrelated patients from Southern Italy with a clinical diagnosis of FH. The mutation screening was performed by direct sequencing of the promoter and the 18 exons of the LDLR gene and by multiplex ligation-dependent probe amplification (MLPA) analysis to search for large rearrangements.

Results and conclusion: We found 5 new mutations, the causative role of which was demonstrated by functional characterization performed by quantification of fluorescent LDL uptake in EBV-transformed B lymphocytes. These results enlarge the spectrum of FH-causative LDLR mutations. Lastly, screening for large rearrangements is highly recommended for the genetic diagnosis of FH.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apolipoprotein B-100 / genetics
  • Apolipoprotein B-48
  • Cell Line, Transformed
  • Cell Separation
  • DNA Mutational Analysis
  • DNA, Complementary / metabolism
  • Flow Cytometry
  • Humans
  • Hyperlipoproteinemia Type II / genetics*
  • Italy
  • Leukocytes, Mononuclear / cytology
  • Mutation*
  • Proprotein Convertase 9
  • Proprotein Convertases
  • Receptors, LDL / genetics*
  • Sequence Analysis, DNA
  • Serine Endopeptidases / genetics

Substances

  • Apolipoprotein B-100
  • Apolipoprotein B-48
  • DNA, Complementary
  • Receptors, LDL
  • PCSK9 protein, human
  • Proprotein Convertase 9
  • Proprotein Convertases
  • Serine Endopeptidases