title: Targeted genetic testing for familial hypercholesterolaemia using next generation sequencing: a population-based study.
abstract: BACKGROUND
  Familial hypercholesterolaemia (FH) is a common Mendelian condition which, untreated, results in premature coronary heart disease. An estimated 88% of FH cases are undiagnosed in the UK. We previously validated a method for FH mutation detection in a lipid clinic population using next generation sequencing (NGS), but this did not address the challenge of identifying index cases in primary care where most undiagnosed patients receive healthcare. Here, we evaluate the targeted use of NGS as a potential route to diagnosis of FH in a primary care population subset selected for hypercholesterolaemia.
  
  
  METHODS
  We used microfluidics-based PCR amplification coupled with NGS and multiplex ligation-dependent probe amplification (MLPA) to detect mutations in LDLR, APOB and PCSK9 in three phenotypic groups within the Generation Scotland: Scottish Family Health Study including 193 individuals with high total cholesterol, 232 with moderately high total cholesterol despite cholesterol-lowering therapy, and 192 normocholesterolaemic controls.
  
  
  RESULTS
  Pathogenic mutations were found in 2.1% of hypercholesterolaemic individuals, in 2.2% of subjects on cholesterol-lowering therapy and in 42% of their available first-degree relatives. In addition, variants of uncertain clinical significance (VUCS) were detected in 1.4% of the hypercholesterolaemic and cholesterol-lowering therapy groups. No pathogenic variants or VUCS were detected in controls.
  
  
  CONCLUSIONS
  We demonstrated that population-based genetic testing using these protocols is able to deliver definitive molecular diagnoses of FH in individuals with high cholesterol or on cholesterol-lowering therapy. The lower cost and labour associated with NGS-based testing may increase the attractiveness of a population-based approach to FH detection compared to genetic testing with conventional sequencing. This could provide one route to increasing the present low percentage of FH cases with a genetic diagnosis.
authors: Penny J
authors: PJ
authors: Norsworthy
authors: Jana
authors: J
authors: Vandrovcova
authors: Ellen R A
authors: ER
authors: Thomas
authors: Archie
authors: A
authors: Campbell
authors: Shona M
authors: SM
authors: Kerr
authors: Jennifer
authors: J
authors: Biggs
authors: Laurence
authors: L
authors: Game
authors: Anne K
authors: AK
authors: Soutar
authors: Blair H
authors: BH
authors: Smith
authors: Anna F
authors: AF
authors: Dominiczak
authors: David J
authors: DJ
authors: Porteous
authors: Andrew D
authors: AD
authors: Morris
authors: Generation
authors: G
authors: Scotland
authors: MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College London, London, UK. tim.aitman@ed.ac.uk.
authors: Timothy J
authors: TJ
authors: Aitman
mesh_terms: D000328:Adult; D000368:Aged; D004252:DNA Mutational Analysis; D005260:Female; D005820:Genetic Testing / Q000379:methods; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases / Q000235:genetics; D011973:Receptors, LDL / Q000235:genetics; D012606:Scotland / Q000453:epidemiology; D012697:Serine Endopeptidases / Q000235:genetics
chemical_list: D011973:Receptors, LDL; C472125:PCSK9 protein, human; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012697:Serine Endopeptidases