Background
Insulin resistance (IR) is one of the major metabolic complications of obesity in children and adolescents. DEP domain‐containing mammalian target of rapamycin interacting protein (DEPTOR) ...is involved in downstream insulin signaling and DEPTOR's effects are regulated by its level of expression.
Objectives
To analyze promoter region of DEPTOR for genetic variants associated with altered IR in obese children and adolescents.
Subjects and methods
IR was determined in 322 normoglycemic obese subjects 173 females, 149 males; mean age 13.3 ± 3.5 yr, mean BMI‐SDS 2.85 ± 0.83, HbA1C 5.2 ± 0.2% (33 ± 2.5 mmol/mol) using homeostatic model assessment – insulin resistance HOMA‐IR (>2 prepubertal and >3 pubertal) and whole body insulin sensitivity index WBISI (<6.5 prepubertal and <4.5 pubertal). Genetic variants, determined by high resolution melting analysis, were confirmed by Sanger sequencing, whereas population allele distribution was determined by TaqMan genotyping probes.
Results
Genetic variant c.‐143T>C (rs7840156) was associated with a significant 2‐fold decreased risk to present with IR, determined by HOMA‐IR odds ratio (OR) = 0.614, 95% confidence interval (CI) = 0.435–0.867, p = 0.0057) and WBISI (OR = 0.582, 95% CI = 0.414–0.817, p = 0.0018). The CC genotype had lower mean HOMA‐IR value (2.47 ± 0.44 vs. 3.04 ± 0.14, p = 0.0177) and higher mean WBISI value (7.00 ± 0.71 vs. 5.27 ± 0.33, p = 0.0235) than TT genotype. Variant c.‐143T>C was located in evolutionary highly conserved region in DEPTOR promoter region.
Conclusion
Presented results on association between insulin sensitivity and genetic variants in DEPTOR gene suggest DEPTOR and mammalian target of rapamycin signaling pathway to be potential target for future research and pharmacological interventions.
•SCN1A polymorphism c.3184A>G/p.Thr1067Ala was studied in European epilepsy patients.•Carriers of G allele of SCNA1 c.3184A>G tended to have lower epilepsy risk.•Patients in remission were older at ...first seizure than those without remission.•The SCN1A c.3184A>G/p.Thr1067Ala G allele was associated with higher remission rate.•A functional SCN1A c.3184A>G/p.Thr1067Ala polymorphism may influence drug response.
The voltage-gated sodium channel SCN1A mutations are involved in epileptogenesis and may be associated with different epilepsy phenotypes. The SCN1A channel is also an important antiepileptic drug (AED) target. The aim of this study was to investigate if the SCN1A c.3184A>G/p.Thr1067Ala polymorphism modifies the epilepsy risk or is associated with the responsiveness to AEDs in Slovenian children and adolescents with epilepsy.
In total, 216 paediatric patients with epilepsy were consecutively recruited during routine outpatient follow-up visits between January 2011 and December 2014. All patients and 95 healthy controls, all Central European Caucasians, were genotyped for the SCN1A c.3184A>G/p.Thr1067Ala polymorphism. Clinical data on all patients were collected retrospectively. The response to AEDs was classified as seizure remission (a minimum of one year of seizure freedom before inclusion) or no remission. Univariate and multivariate logistic regression was used to determine the association of genotypes with binary outcomes.
114 patients (52.8%) had achieved remission, while 102 (47.2%) had failed to do so. Carriers of at least one polymorphic SCN1A c.3184A>G/p.Thr1067Ala G allele tended to have a lower epilepsy risk (OR=0.38, 95% CI=0.18–0.79, P=0.010) and were significantly more likely to achieve remission (OR=2.00, 95% CI=1.16–3.46, P=0.013). Girls were less likely to achieve remission (P=0.055). Patients in remission tended to be older at first seizure in comparison to the group failing to achieve remission (OR=1.06, 95% CI=0.99–1.14, P=0.099), but this association did not reach statistical significance.
The polymorphic SCN1A c.3184A>G/p.Thr1067Ala G allele was associated with a lower risk of epilepsy and a higher remission rate in Slovenian children and adolescents with epilepsy.
Lipoprotein(a) (Lp(a)) is an independent risk factor for future coronary events. Variants rs10455872 and rs3798220 in the gene encoding Lp(a) are associated with an increased Lp(a) concentration and ...risk of coronary artery disease. We aimed to determine whether in high-risk coronary artery disease patients these two genetic variants and the kringle IV type 2 (KIV-2) repeats are associated with impairment of inflammatory and hemostatic parameters. Patients after myocardial infarction with elevated Lp(a) levels were included. Blood samples underwent biochemical and genetic analyses. In carriers of the AC haplotype, the concentrations of tumor necrosis factor (TNF)-α (4.46 vs. 3.91 ng/L,
= 0.046) and plasminogen activator inhibitor-1 (PAI-1) (
= 0.026) were significantly higher compared to non-carriers. The number of KIV-2 repeats was significantly associated with the concentration of high-sensitivity C-reactive protein (ρ = 0.251,
= 0.038) and overall fibrinolytic potential (r = -0.253,
= 0.038). In our patients, a direct association between the AC haplotype and both TNF-α and PAI-1 levels was observed. Our study shows that the number of KIV-2 repeats not only affects proatherosclerotic and proinflammatory effects of Lp(a) but is also associated with its antifibrinolytic properties.
Context: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease associated with mutations in the AIRE gene.
Objective: Our objective was to ...investigate clinical and mutational characteristics of 12 Slovenian patients from 10 families with APECED.
Methods: Direct sequencing, restriction fragment length polymorphism, and amplification refractory mutation system analyses were used to identify AIRE gene mutations. Autoimmune regulator (AIRE)-1 mRNA analysis was used to confirm pathogenicity of the intronic mutation.
Results: The prevalence of APECED in Slovenian population was estimated to be 1 in 43,000, which is significantly higher compared with the neighboring populations. Three novel mutations were identified among six different mutations detected in the AIRE gene. The first novel mutation was an intronic mutation (653-7_-5delCTC) affecting proper splicing by using a nearby new acceptor splice site as demonstrated by AIRE-1 mRNA analyses. The second and third novel mutations were frame-shift mutations located in exon 5 (540delG) and exon 9 (1064-1068dupCCCGG), both leading to premature truncation of the AIRE protein. The Finnish R257X mutation was the most frequent AIRE gene mutation in Slovenian patients with APECED (16 of 24 alleles).
Conclusions: Three novel AIRE gene mutations were identified. For the first time, a novel intronic mutation was investigated on the mRNA level in APECED. This could be particularly important for APECED patients where no or only heterozygous mutation on the genomic DNA level is detected.
The aims of the study were to identify craniofacial characteristics in patients with the rough hypoplastic amelogenesis imperfecta (AI) phenotype and to evaluate whether craniofacial variables are ...related to a mutation in either of the two genes associated with AI, enamelin (ENAM) and amelogenin (AMGX). Eight children (five males and three females) with rough hypoplastic AI phenotype, aged 6.5-15 years, from three families and their parents (three males and three females) were examined clinically, radiographically, and genetically. Seventeen variables were measured on lateral cephalometric radiographs in AI affected (n = 11) and AI unaffected (n = 3) members. Craniofacial measurements were statistically analysed using a Student's t-test. In all 14 individuals, mutation analysis of the ENAM and AMGX genes was performed by direct sequencing of the coding region. All AI affected patients had hypoplastic enamel with a rough surface and malocclusions. In the vertical plane, all AI children presented an anterior and/or posterior open bite (OB). Craniofacial analysis confirmed increased vertical relationships, with increased vertical jaw relationships and higher values for gonial angle. In two AI affected families, A and B, the same heterozygous ENAM g.8344delG mutation was confirmed, while in the third family, neither ENAM nor AMGX mutation was found. All patients with rough hypoplastic AI had a moderate to severe malocclusion with increased vertical dimensions regardless of the presence or absence of the ENAM g.8344delG mutation. As an OB requires appropriate timing of therapy, it is important to diagnose these patients as early as possible.
High titer autoantibodies produced by B lymphocytes are clinically important features of many common autoimmune diseases. APECED patients with deficient autoimmune regulator (AIRE) gene collectively ...display a broad repertoire of high titer autoantibodies, including some which are pathognomonic for major autoimmune diseases. AIRE deficiency severely reduces thymic expression of gene-products ordinarily restricted to discrete peripheral tissues, and developing T cells reactive to those gene-products are not inactivated during their development. However, the extent of the autoantibody repertoire in APECED and its relation to thymic expression of self-antigens are unclear. We here undertook a broad protein array approach to assess autoantibody repertoire in APECED patients. Our results show that in addition to shared autoantigen reactivities, APECED patients display high inter-individual variation in their autoantigen profiles, which collectively are enriched in evolutionarily conserved, cytosolic and nuclear phosphoproteins. The APECED autoantigens have two major origins; proteins expressed in thymic medullary epithelial cells and proteins expressed in lymphoid cells. These findings support the hypothesis that specific protein properties strongly contribute to the etiology of B cell autoimmunity.
The prevalence of the autism spectrum disorder (ASD) was recently estimated to 1 in 88 children by the CDC MMWR. In up to 25 % of the cases, the genetic cause can be identified. Past studies ...identified increased level of advanced glycation end products (AGE) in the brain samples of ASD patients. The methylglyoxal (MG) is one of the main precursors for AGE formation. Humans developed effective mechanism of the MG metabolism involving two enzymes glyoxalase 1 (
GLO1
) and hydroxyacylglutathione hydrolase (
HAGH
). Our aim was to analyse genetic variants of
GLO1
and
HAGH
in population of 143 paediatric participants with ASD. We detected 7 genetic variants in
GLO1
and 16 variants in
HAGH
using high-resolution melting (HRM) analysis. A novel association between variant rs1049346 and ASD OR
(allele C)
= 1.5; 95 % CI = 1.1–2.2 and
p
< 0.05) was identified, and weak association between ASD and variant rs2736654 OR
(allele A)
= 2.2; 95 % CI = 0.99–4.9;
p
= 0.045) was confirmed. Additionally, a novel genetic variant (
GLO1 c.484G
>
A
, p.Ala161Thr) with predicted potentially damaging effect on the activity of the glyoxalase 1 that may contribute to the aetiology of ASD was identified in one participant with ASD. No association between genetic variants of the
HAGH
gene and ASD was found. Increased level of MG and, consequently, AGEs can induce oxidative stress, mitochondrial dysfunction and inflammation all of which have been implicated to act in the aetiology of the ASD. Our results indicate potential importance of MG metabolism in ASD. However, these results must be interpreted with caution until a causative relation is demonstrated.
Donohue syndrome (leprechaunism; OMIM *246200) is a rare, recessively inherited disorder of extreme insulin resistance due to mutations in the insulin receptor gene (
INSR
) causing either defects in ...insulin binding or receptor autophosphorylation and tyrosine kinase activity. We report a patient with pronounced clinical picture of leprechaunism who developed severe progressive hypertrophic obstructive cardiomyopathy (HOCM) and renal tubular dysfunction which improved on continuous subcutaneous infusion of recombinant human insulin-like growth factor-1 (rhIGF-I).
INSR
gene molecular analysis and insulin receptor (IR) autophosphorylation on cultured fibroblasts were performed. A novel homozygous missense mutation p.Leu795Pro was found, located in the extracellular portion of the β subunit of the insulin receptor. The post-binding defect of the insulin receptor signaling in cultured fibroblasts demonstrated decreased insulin receptor autophosphorylation. Conclusion: Treatment with rhIGF-I partially reversed severe progressive HOCM and renal tubular dysfunction in a patient with Donohue syndrome associated with a novel p.Leu795Pro
INSR
gene mutation causing a severe decrease in IR autophosphorylation.
Introduction
Both autoimmune polyendocrinopathy‐candidiasis‐ectodermal dystrophy (APECED) and the rare thymoma patients with chronic mucocutaneous candidiasis (CMC) have neutralizing autoantibodies ...to Th17 cytokines and significant defects in production of IL‐22 and IL‐17F by their T cells. The cause of these defects is unknown. We hypothesized that they might result from autoimmunity against upstream cytokines normally responsible for generating and maintaining Th17 cells.
Methods
Luciferase immunoprecipitation (LIPS) was used to screen for autoantibodies to IL‐6, IL‐1β, TGF‐β3, IL‐21, and IL‐23 in patients with APECED or thymoma. We used Western blotting to assess the conformation‐dependence of the IL‐6 autoantibodies and flow cytometric analysis of intracellular phospho‐STAT3 induction to assess IL‐6‐neutralizing capacity in IgGs isolated from patient and control sera. We also used Luminex xMAP to measure serum cytokine levels.
Results
We found autoantibodies binding to conformational epitopes of IL‐6 in 19.5% of 41 patients with APECED and 12.5% of 104 with thymoma—especially in those with long disease durations. The autoantibodies were predominantly of IgG1 subclass and failed to neutralize IL‐6 activity. Notably, serum levels of the IL‐6 and IL‐17A cytokines were higher in anti‐IL‐6 seropositive than—negative APECED patients or healthy controls. We also detected autoantibody binding to IL‐23 in 27.9% of thymoma patients, resulting from cross‐recognition through the p40 subunit it shares with IL‐12.
Conclusions
IL‐6 and IL‐17A elevation in these seropositive patients suggests that antibody‐binding may protect IL‐6 from degradation and prolong its half‐life in vivo.
Autoantibodies to IL‐6 in APECED and thymoma patients are mainly of IgG1 isotype, bind to conformational epitopes, and are not neutralizing. Autoreactivity toward IL‐23 in thymoma patients is explained by crossreactivity with IL‐12 p40 subunit.
Patients with biallelic loss-of-function variants of AIRE suffer from autoimmune polyendocrine syndrome type-1 (APS-1) and produce a broad range of autoantibodies (auto-Abs), including circulating ...auto-Abs neutralizing most type I interferons (IFNs). These auto-Abs were recently reported to account for at least 10% of cases of life-threatening COVID-19 pneumonia in the general population. We report 22 APS-1 patients from 21 kindreds in seven countries, aged between 8 and 48 yr and infected with SARS-CoV-2 since February 2020. The 21 patients tested had auto-Abs neutralizing IFN-α subtypes and/or IFN-ω; one had anti-IFN-β and another anti-IFN-ε, but none had anti-IFN-κ. Strikingly, 19 patients (86%) were hospitalized for COVID-19 pneumonia, including 15 (68%) admitted to an intensive care unit, 11 (50%) who required mechanical ventilation, and four (18%) who died. Ambulatory disease in three patients (14%) was possibly accounted for by prior or early specific interventions. Preexisting auto-Abs neutralizing type I IFNs in APS-1 patients confer a very high risk of life-threatening COVID-19 pneumonia at any age.
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