High-maintenance proteins and hypertriglyceridemia

Transfer learning-trained convolutional neural networks identify novel MRI biomarkers of Alzheimer's disease progression

INTRODUCTION

Genome-wide association studies (GWAS) for late onset Alzheimer's disease (AD) may miss genetic variants relevant for delineating disease stages when using clinically defined case/control as a phenotype due to its loose definition and heterogeneity.

METHODS

We use a transfer learning technique to train three-dimensional convolutional neural network (CNN) models based on structural magnetic resonance imaging (MRI) from the screening stage in the Alzheimer's Disease Neuroimaging Initiative consortium to derive image features that reflect AD progression.

RESULTS

CNN-derived image phenotypes are significantly associated with fasting metabolites related to early lipid metabolic changes as well as insulin resistance and with genetic variants mapped to candidate genes enriched for amyloid beta degradation, tau phosphorylation, calcium ion binding-dependent synaptic loss, APP-regulated inflammation response, and insulin resistance.

DISCUSSION

This is the first attempt to show that non-invasive MRI biomarkers are linked to AD progression characteristics, reinforcing their use in early AD diagnosis and monitoring.

Novel LPL mutations associated with lipoprotein lipase deficiency: two case reports and a literature review

Lipoprotein lipase (LPL) is a key enzyme involved with hydrolysis and removal of triglycerides from plasma. LPL deficiency is a rare condition with an estimated prevalence of 1 in 106. It is characterized biochemically by elevated triglycerides and lowered HDL in the plasma and clinically by a constellation of signs and symptoms during childhood including failure to thrive, lipemia retinalis, eruptive xanthomas, hepatosplenomegaly, and acute pancreatitis. Nearly 100 mutations in the LPL gene have been associated with LPL deficiency. Here we report 2 unrelated pedigrees with LPL deficiency from 2 novel disease-causing LPL mutations: a Gly159Glu missense mutation in exon 5 and a 4-bp ACGG deletion at the 3' boundary of exon 2. We present molecular findings of these 2 cases and review the biochemical, clinical, and genetic features of LPL deficiency.

Common sequence variant in lipoprotein lipase gene conferring triglyceride response to fibrate treatment

Aims: Little is known about whether the variations in the lipoprotein lipase (LPL) and apolipoprotein gene cluster (APOA1/C3/A5) confer appreciable triglyceride lowering after fibrate treatment among patients with hypertriglyceridemia. Materials & methods: We investigated whether variations in these genes confer a triglyceride lowering response after fibrate treatment among 145 patients with hypertriglyceridemia receiving 6 months of fibrate treatment. Results: Overall triglycerides decreased from 746.2 mg/dl to 465.9 mg/dl and the mean percentage of triglyceride lowering was 50.7 ± 38.6%. A total of two polymorphisms, LPL IVS8 +483T>G and APOA1 +2169G>C, were associated with a significant percentage of triglyceride lowering. Common haplotype effects of LPL on the triglyceride lowering percentage were significant (p = 0.002) and the percentage of variance explained by the LPL haplotype was 7.5%. One common LPL haplotype encompassing three polymorphisms was associated with a -45.40% change (p < 0.001) and risk of a 5.9-fold risk for developing a poor response (95% confidence interval: 1.11–31, p = 0.037), compared with the most frequent LPL haplotype. Conclusion: Our results indicate that the LPL gene variant may cause triglyceride lowering after fibrate treatment among patients with hypertriglyceridemia.