A wide next-generation-sequencing panel improves the molecular diagnosis of dyslipidemias

Introduction: Dyslipidemias are common clinical conditions associated to cardiovascular diseases. Among these, Familial Hypercholesterolemia (FH) and severe Hypertriglyceridemia (sHTG) are the most frequent ones. The aim of this study is to evaluate the possible use of a wide next-generation-sequencing (NGS) panel of 28 genes involved in lipid metabolism, to improve the molecular diagnosis of dyslipidemias. Methods: A reanalysis of 25 patients (21 FH and 4 sHTG) previously analyzed for a few causative genes has been carried on. Patients bearing different types of variants [single nucleotide variants (SNVs) and copy number variations (CNVs)] in different genes, previously analyzed with Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) have been selected. DNA libraries have been prepared using Agilent SureSelect target enrichment protocol; the sequencing has been performed using Illumina MiSeq (V2 150x2 Micro). The results of the sequencing have been evaluated by Agilent SureCall and Agilent Alissa Align & Call and Intrepret pipelines. Results: All previously identified SNVs and CNVs have been confirmed by NGS. Additional rare variants, not always associated with dyslipidemias, were found in 23/25 patients. An additional pathogenic variant in the APOB gene has been identified in a sHTG patient carrying only 1 pathogenic variant in the APOA5 gene (causative of sHTG). Conclusions: The NGS-method confirmed all the results obtained with direct sequencing and MLPA methodologies. Additional rare variants were detected, even if most of them turned out to be variant of uncertain significance (VUS). In conclusion, this NGS approach may enhance the molecular diagnosis of different types of dyslipidemias, thereby leading to a better understanding and detection of complex phenotypes.