Identification of novel APOB mutations by targeted next-generation sequencing for the molecular diagnosis of familial hypobetalipoproteinemia

Antoine Rimbert (1) , Matthieu Pichelin (1, 1) , Simon Lecointe (1) , Marie Marrec (1) , Solena Le Scouarnec (1) , Elias Barrak (1) , Mikael Croyal , Michel Krempf , Hervé Le Marec (1) , Richard Redon (1) , Jean-Jacques Schott (1) , Jocelyne Magré (1) , Bertrand Cariou (1)

1 ITX - ITX - unité de recherche de l'institut du thorax

BACKGROUND AND AIMS: Familial hypobetalipoproteinemia (FHBL) is a co-dominant disorder characterized by decreased plasma levels of LDL-cholesterol and apolipoprotein B (ApoB). Currently, genetic diagnosis in FHBL relies largely on Sanger sequencing to identify APOB and PCSK9 gene mutations and on western blotting to detect truncated ApoB species. METHODS: Here, we applied targeted enrichment and next-generation sequencing (NGS) on a panel of three FHBL genes and two abetalipoproteinemia genes (APOB, PCSK9, ANGPTL3, MTTP and SAR1B). RESULTS: In this study, we identified five likely pathogenic heterozygous rare variants. These include four novel nonsense mutations in APOB (p.Gln845*, p.Gln2571*, p.Cys2933* and p.Ser3718*) and a rare variant in PCSK9 (Minor Allele Frequency \textless0.1%). The affected family members tested were shown to be carriers, suggesting co-segregation with low LDL-C. CONCLUSIONS: Our study further demonstrates that NGS is a reliable and practical approach for the molecular screening of FHBL-causative genes that may provide a mean for deciphering the genetic basis in FHBL.

Mots clés: Target next generation sequencing; Familial hypobetalipoproteinemia; APOB; Molecular diagnosis; PCSK9

Domaines: Sciences du Vivant [q-bio]

Antoine Rimbert, Matthieu Pichelin, Simon Lecointe, Marie Marrec, Solena Le Scouarnec, et al.. Identification of novel APOB mutations by targeted next-generation sequencing for the molecular diagnosis of familial hypobetalipoproteinemia. Atherosclerosis, 2016, Equipe 3 Equipe 4 Equipe 5, 250, pp.52--56. ⟨10.1016/j.atherosclerosis.2016.04.010⟩. ⟨hal-01831745⟩