Aicardi–Goutières syndrome is an inflammatory disease occurring due to mutations in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR or IFIH1. We report on 374 patients from 299 families with mutations in these seven genes. Most patients conformed to one of two fairly stereotyped clinical profiles; either exhibiting an in utero disease-onset (74 patients; 22.8% of all patients where data were available), or a post-natal presentation, usually within the first year of life (223 patients; 68.6%), characterized by a sub-acute encephalopathy and a loss of previously acquired skills. Other clinically distinct phenotypes were also observed; particularly, bilateral striatal necrosis (13 patients; 3.6%) and non-syndromic spastic paraparesis (12 patients; 3.4%). We recorded 69 deaths (19.3% of patients with follow-up data). Of 285 patients for whom data were available, 210 (73.7%) were profoundly disabled, with no useful motor, speech and intellectual function. Chilblains, glaucoma, hypothyroidism, cardiomyopathy, intracerebral vasculitis, peripheral neuropathy, bowel inflammation and systemic lupus erythematosus were seen frequently enough to be confirmed as real associations with the Aicardi-Goutieres syndrome phenotype. We observed a robust relationship between mutations in all seven genes with increased type I interferon activity in cerebrospinal fluid and serum, and the increased expression of interferon-stimulated gene transcripts in peripheral blood. We recorded a positive correlation between the level of cerebrospinal fluid interferon activity assayed within one year of disease presentation and the degree of subsequent disability. Interferon-stimulated gene transcripts remained high in most patients, indicating an ongoing disease process. On the basis of substantial morbidity and mortality, our data highlight the urgent need to define coherent treatment strategies for the phenotypes associated with mutations in the Aicardi–Goutières syndrome-related genes. Our findings also make it clear that a window of therapeutic opportunity exists relevant to the majority of affected patients and indicate that the assessment of type I interferon activity might serve as a useful biomarker in future clinical trials.
The type I interferon system is integral to human antiviral immunity. However, inappropriate stimulation or defective negative regulation of this system can lead to inflammatory disease. We sought to determine the molecular basis of genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, and of other patients with undefined neurological and immunological phenotypes also demonstrating an upregulated type I interferon response. We found that heterozygous mutations in the cytosolic double-stranded RNA receptor gene IFIH1 (MDA5) cause a spectrum of neuro-immunological features consistently associated with an enhanced interferon state. Cellular and biochemical assays indicate that these mutations confer a gain-of-function - so that mutant IFIH1 binds RNA more avidly, leading to increased baseline and ligand-induced interferon signaling. Our results demonstrate that aberrant sensing of nucleic acids can cause immune upregulation.
In developed countries, obesity is the most frequent nutritional disorder, and overweight and obesity prevalences have increased whilst physical activity and breakfast consumption have declined. There is growing scientific interest in the possible role of breakfast in weight control and in factors such as appetite control, dietary quality and reduced risk for chronic diseases. The current article reviews the literature and discusses how the breakfast 'environment' and the composition of breakfast meals might be improved, particularly in children, so as to maintain the breakfast eating habit throughout life. Recommendations are proposed to encourage children to keep eating breakfast and the nutritional composition of the 'American breakfast' and two types of Mediterranean 'cereal breakfasts' are compared. We also propose a new breakfast type for children and adolescents that is based on chocolate hazelnut spread within a mixed breakfast type in order to reinforce positive experiences.
Despite the appearance of new treatment, dietary approach remains the mainstay of PKU therapy. The nutritional management has become complex to optimize PKU patients' growth, development and diet compliance. This paper review critically new advances and challenges that have recently focused attention on potential relevant of LCPUFA supplementation, progress in protein substitutes and new protein sources, large neutral amino acids and sapropterin. Given the functional effects, DHA is conditionally essential substrates that should be supplied with PKU diet in infancy but even beyond. An European Commission Programme is going on to establish quantitative DHA requirements in this population. Improvements in the palatability, presentation, convenience and nutritional composition of protein substitutes have helped to improve long-term compliance with PKU diet, although it can be expected for further improvement in this area. Glycomacropeptide, a new protein source, may help to support dietary compliance of PKU subject but further studies are needed to evaluate this metabolic and nutritional issues. The PKU diet is difficult to maintain in adolescence and adult life. Treatment with large neutral amino acids or sapropterin in selected cases can be helpful. However, more studies are necessary to investigate the potential role, dose, and composition of large neutral amino acids in PKU treatment and to show long-term efficacy and tolerance. Ideally treatment with sapropterin would lead to acceptable blood Phe control without dietary treatment but this is uncommon and sapropterin will usually be given in combination with dietary treatment, but clinical protocol evaluating adjustment of PKU diet and sapropterin dosage are needed.In conclusion PKU diet and the new existing treatments, that need to be optimized, may be a complete and combined strategy possibly positive impacting on the psychological, social, and neurocognitive life of PKU patients.
There is some evidence that early colonization of the intestine affects the composition of the intestinal microbiota after weaning. In the present study, the effect of prebiotics administered from the first day of life on fecal counts of bifidobacteria and lactobacilli were studied during and after the administration of the prebiotics. In this double-blind, randomized, placebo-controlled, explorative study, 20 newborns of hepatitis C virus-infected mothers who decided not to breast feed due to their concerns regarding their plasma viral load were randomly assigned to either a formula with 8 g/L of a specific prebiotic mixture (short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides, ratio 9:1) or a formula containing the same amount of maltodextrin (placebo). Clinical examination including anthropometric measurements, microbiological analysis of fecal samples, and blood leukocyte population analysis were performed at birth and 3, 6, and 12 mo age. At the age of 12 mo, hepatitis B vaccine-specific IgG serum titers (Hepatitis B virus surface antibodies) were also measured. Prebiotic supplementation resulted in more fecal bifidobacteria (P < 0.0001) and lactobacilli (P = 0.0044) compared with the placebo group. These differences between the groups were maintained during the second half of the first year without any prebiotic supplementation. There was no influence of the different diets on anthropometric data or the measured immunological variables. The data from this small explorative study indicate that early colonization of the intestine might have long-lasting effects on the composition of the intestinal microbiota.
PKU subjects need special attention in the definition of optimal supplementation of nutrients, which may be insufficient in relation to the type of diet and may otherwise manifest symptoms of deficit. In particular, it is necessary to pay great attention to the long-chain polyunsaturated fatty acid (LC-PUFA) levels in relation to correct development of the central nervous system. On the basis of numerous beneficial effects currently known, a permanent supplementation with LC-PUFAs, in particular with docosahexaenoic acid, should be considered. Moreover, new formulas, Phe-free peptides, and 'modulated' amino acid preparations might help in preventing nutritional deficiencies and imbalances, with the ultimate aim of improving growth. New strategies--such as supply of tetrahydrobiopterin--need to be optimized in terms of targets, patients and expected outcomes.
Aicardi-Goutières syndrome (AGS) is a genetically determined early onset encephalopathy characterized by cerebral calcification, leukodystrophy, and increased expression of interferon-stimulated genes (ISGs). Up to now, seven genes (TREX1, RNASEH2B, RNASEH2C, RNASEH2A, ADAR1, SAMHD1, IFIH1) have been associated with an AGS phenotype. Next Generation Sequencing (NGS) analysis was performed on 51 AGS patients and interferon signature (IS) was investigated in 18 AGS patients and 31 healthy controls. NGS identified mutations in 48 of 51 subjects, with three patients demonstrating a typical AGS phenotype but not carrying mutations in known AGS-related genes. Five mutations, in RNASEH2B, SAMHD1 and IFIH1 gene, were not previously reported. Eleven patients were positive and seven negatives for the upregulation of interferon signaling (IS > 2.216). This work presents, for the first time, the genetic data of an Italian cohort of AGS patients, with a higher percentage of mutations in RNASEH2B and a lower frequency of mutations in TREX1 than those seen in international series. RNASEH2B mutated patients showed a prevalence of negative IS consistent with data reported in the literature. We also identified five novel pathogenic mutations that warrant further functional investigation. Exome/genome sequencing will be performed in future studies in patients without a mutation in AGS-related genes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.