A homozygous variant in the GPIHBP1 gene in a child with severe hypertriglyceridemia and a systematic literature review.

Background: Due to nonspecific symptoms, rare dyslipidaemias are frequently misdiagnosed, overlooked, and undertreated, leading to increased risk for severe cardiovascular disease, pancreatitis and/or multiple organ failures before diagnosis. Better guidelines for the recognition and early diagnosis of rare dyslipidaemias are urgently required. Methods: Genomic DNA was isolated from blood samples of a Pakistani paediatric patient with hypertriglyceridemia, and from his parents and siblings. Next-generation sequencing (NGS) was performed, and an expanded dyslipidaemia panel was employed for genetic analysis. Results: The NGS revealed the presence of a homozygous missense pathogenic variant c.230G>A (NM_178172.6) in exon 3 of the GPIHBP1 (glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1) gene resulting in amino acid change p.Cys77Tyr (NP_835466.2). The patient was 5.5 years old at the time of genetic diagnosis. The maximal total cholesterol and triglyceride levels were measured at the age of 10 months (850.7 mg/dl, 22.0 mmol/L and 5,137 mg/dl, 58.0 mmol/L, respectively). The patient had cholesterol deposits at the hard palate, eruptive xanthomas, lethargy, poor appetite, and mild splenomegaly. Both parents and sister were heterozygous for the familial variant in the GPIHBP1 gene. Moreover, in the systematic review, we present 62 patients with pathogenic variants in the GPIHBP1 gene and clinical findings, associated with hyperlipoproteinemia. Conclusion: In a child with severe hypertriglyceridemia, we identified a pathogenic variant in the GPIHBP1 gene causing hyperlipoproteinemia (type 1D). In cases of severe elevations of plasma cholesterol and/or triglycerides genetic testing for rare dyslipidaemias should be performed as soon as possible for optimal therapy and patient management.

Ligand Selection for Affinity Chromatography Using Phage Display.

Phage display coupled with in vitro affinity selection to mimic evolutionary principles has propelled the discovery of specific binding peptides and proteins for diverse applications, including affinity chromatography. By tailoring screening conditions, ligands with desired predefined properties, such as pH- or ion strength-responsive binding, can be identified from phage-displayed combinatorial peptide libraries. Initial hit peptides can be further optimized through directed evolution by focused mutagenesis and rescreening. Quantitative analysis of eluted binders with next-generation sequencing (NGS) assists in reducing enrichment bias and simplifies picking the most promising ligand candidate(s) through enrichment ranking. We describe, in detail, procedures of ligand selection for affinity chromatography using peptide phage display library screening, focused mutagenesis, and NGS. Furthermore, we outline the subsequent workflow for ligand characterization and affinity column construction.

Heterozygous Genetic Variants in Autosomal Recessive Genes of the Leptin-Melanocortin Signalling Pathway Are Associated With the Development of Childhood Obesity.

Monogenic obesity is a severe, genetically determined disorder that affects up to 1/1000 newborns. Recent reports on potential new therapeutics and innovative clinical approaches have highlighted the need for early identification of individuals with rare genetic variants that can alter the functioning of the leptin-melanocortin signalling pathway, in order to speed up clinical intervention and reduce the risk of chronic complications. Therefore, next-generation DNA sequencing of central genes in the leptin-melanocortin pathway was performed in 1508 children and adolescents with and without obesity, aged 2-19 years. The recruited cohort comprised approximately 5% of the national paediatric population with obesity. The model-estimated effect size of rare variants in the leptin-melanocortin signalling pathway on longitudinal weight gain between carriers and non-carriers was derived. In total, 21 (1.4%) participants had known disease-causing heterozygous variants (DCVs) in the genes under investigation, and 62 (4.1%) participants were carriers of rare variants of unknown clinical significance (VUS). The estimated frequency of potential genetic variants associated with obesity (including rare VUS) ranged between 1/150 (VUS and DCV) and 1/850 (DCV) and differed significantly between participants with and without obesity. On average, the variants identified would result in approximately 7.6 kg (7.0-12.9 kg at the 95th percentile of body weight) (girls) and 8.4 kg (8.2-14.4 kg) (boys) of additional weight gain in carriers at age 18 years compared with subjects without obesity. In conclusion, children with a genetic predisposition to obesity can be promptly identified and may account for more than 6% of obesity cases. Early identification of genetic variants in the LEPR, PCSK1, POMC, MC3R and MC4R genes could reduce the societal burden and improve the clinical management of early severe childhood obesity and its implementation should be further investigated.

Multiomics Analysis Coupled with Text Mining Identify Novel Biomarker Candidates for Recurrent Cardiovascular Events.

Recurrent cardiovascular events remain an enigma that accounts for >30% of deaths worldwide. While heredity and human genetics variation play a key role, host-environment interactions offer a sound conceptual framework to dissect the molecular basis of recurrent cardiovascular events from genes and proteins to metabolites, thus accounting for environmental contributions as well. We report here a multiomics systems science approach so as to map interindividual variability in susceptibility to recurrent cardiovascular events. First, we performed data and text mining through a mixed-methods content analysis to select genomic variants, 10 single nucleotide polymorphisms, and microRNAs (miR-10a, miR-21, and miR-20a), minimizing bias in candidate marker selection. Next, we validated our in silico data in a patient cohort suffering from recurrent cardiovascular events (a cross-sectional study design and sampling). Our findings report a key role in low-density lipoprotein clearance for rs11206510 (p < 0.01) and rs515135 (p < 0.05). miR-10a (p < 0.05) was significantly associated with heart failure, while increased expression levels for miR-21 and miR-20a associated with atherosclerosis. In addition, liquid chromatography-mass spectrometry-based (LC-MS-based) proteomics analyses identified that vascular diameter and cholesterol levels are among the key factors to be considered in recurrent cardiovascular events. From a methodology innovation standpoint, this study offers a strategy to enhance the signal-to-noise ratios in mapping novel biomarker candidates wherein each research and conceptual step were interrogated for their validity and in turn, enriched one another, ideally translating information growth to knowledge growth.