Identification of a novel LMF1 nonsense mutation responsible for severe hypertriglyceridemia by targeted next-generation sequencing

Background Severe hypertriglyceridemia (HTG) may result from mutations in genes affecting the intravascular lipolysis of triglyceride (TG)-rich lipoproteins. Objective The aim of this study was to develop a targeted next-generation sequencing panel for the molecular diagnosis of disorders characterized by severe HTG. Methods We developed a targeted customized panel for next-generation sequencing Ion Torrent Personal Genome Machine to capture the coding exons and intron/exon boundaries of 18 genes affecting the main pathways of TG synthesis and metabolism. We sequenced 11 samples of patients with severe HTG (TG>885 mg/dL\u201310 mmol/L): 4 positive controls in whom pathogenic mutations had previously been identified by Sanger sequencing and 7 patients in whom the molecular defect was still unknown. Results The customized panel was accurate, and it allowed to confirm genetic variants previously identified in all positive controls with primary severe HTG. Only 1 patient of 7 with HTG was found to be carrier of a homozygous pathogenic mutation of the third novel mutation of LMF1 gene (c.1380C>G\u2013p.Y460X). The clinical and molecular familial cascade screening allowed the identification of 2 additional affected siblings and 7 heterozygous carriers of the mutation. Conclusions We showed that our targeted resequencing approach for genetic diagnosis of severe HTG appears to be accurate, less time consuming, and more economical compared with traditional Sanger resequencing. The identification of pathogenic mutations in candidate genes remains challenging and clinical resequencing should mainly intended for patients with strong clinical criteria for monogenic severe HTG

Baseline metabolic disturbances and the twenty-five years risk of incident cancer in a Mediterranean population

BACKGROUND AND AIMS: Obesity is predictive of metabolic syndrome (metS), type 2 diabetes, cardiovascular (CV) disease and cancer. The aim of the study is to assess the risk of incident cancer connected to obesity and metS in a Mediterranean population characterized by a high prevalence of obesity. METHODS AND RESULTS: As many as 1133 subjects were enrolled in two phases and followed for 25 years (859 subjects) or 11 years (274 subjects) and incident cancer was registered in the follow-up period. Anthropometric measures and biochemical parameters were filed at baseline and evaluated as predictors of incident cancer by measuring hazards ratios (HR) using multivariate Cox parametric hazards models. Best predictive threshold for metabolic parameters and metS criteria were recalculated by ROC analysis. Fasting Blood Glucose >5.19 mmol/L [HR = 1.58 (1.0-2.4)] and the TG/HDL ratio (log10) (Males > 0.225, Females > 0.272) [HR = 2.44 (1.3-4.4)] resulted independent predictors of survival free of cancer with a clear additive effect together with age classes [45-65 years, HR = 2.47 (1.3-4.4), 65-75 years HR = 3.80 (2.0-7.1)] and male gender [HR = 2.07 (2.3-3.1)]. CONCLUSIONS: Metabolic disturbances are predictive of cancer in a 25 years follow-up of a Mediterranean population following a traditional Mediterranean diet. The high prevalence of obesity and metS and the observed underlying condition of insulin resistance expose this population to an increased risk of cardiovascular disease and cancer despite the healthy nutritional habits