Modeling Lysosomal Storage Disorders in an Innovative Way: Establishment and Characterization of Stem Cell Lines from Human Exfoliated Deciduous Teeth of Mucopolysaccharidosis Type II Patients.

Among the many lysosomal storage disorders (LSDs) that would benefit from the establishment of novel cell models, either patient-derived or genetically engineered, is mucopolysaccharidosis type II (MPS II). Here, we present our results on the establishment and characterization of two MPS II patient-derived stem cell line(s) from deciduous baby teeth. To the best of our knowledge, this is the first time a stem cell population has been isolated from LSD patient samples obtained from the dental pulp.

Plasma lipidomics analysis reveals altered profile of triglycerides and phospholipids in children with Medium-Chain Acyl-CoA dehydrogenase deficiency.

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most prevalent mitochondrial fatty acid β-oxidation disorder. In this study, we assessed the variability of the lipid profile in MCADD by analysing plasma samples obtained from 25 children with metabolically controlled MCADD (following a normal diet with frequent feeding and under l-carnitine supplementation) and 21 paediatric control subjects (CT). Gas chromatography-mass spectrometry was employed for the analysis of esterified fatty acids, while high-resolution C18-liquid chromatography-mass spectrometry was used to analyse lipid species.

Mucopolysaccharidosis Type I: The Importance of Early Diagnosis for Adequate Treatment.

Mucopolysaccharidoses are rare lysosomal storage disorders in which glycosaminoglycans accumulate in tissues, causing multiorgan dysfunction. Mucopolysaccharidosis type I is an autosomal recessive disease caused by a deficiency of the enzyme alpha-L-iduronidase, resulting in the accumulation of dermatan and heparan sulfate. Early diagnosis is crucial for early treatment and improved outcomes.

Challenges in Genetic Diagnosis of Mitochondrial Diseases: What Can Functional Genomics' Studies Do?

Introduction: Mitochondrial oxidative phosphorylation (OXPHOS) diseases are challenging both from clinical and therapeutic perspectives. The advent of next-generation sequencing (NGS) boosted the discovery of new genetic defects affecting OXPHOS, with pathogenic variants identified in >350 genes to date [1]. However, in many patients, novel variants of unknown clinical significance are found.

Help Comes from Unexpected Places: How a Tiny Fairy and a Tropical Fish may help us Model Mucopolysaccharidoses.

Introduction: When it comes to disease modeling, countless models are available for Lysosomal Storage Diseases (LSD). Historically, two major approaches are well-established: in vitro assessments are performed in patient fibroblasts, while in vivo pre-clinical studies are performed in mouse models. Still, both platforms have a series of drawbacks.

Palliative Care in Children with Inherited Metabolic Diseases: Why does it matter?

Background: Inherited metabolic diseases (IMD) bring considerable burden on the child and family. Challenging areas for health care include the identification of distressing symptoms, prognostic uncertainty, and bereavement. Literature regarding the impact of paediatric palliative care (PPC) is scarce.

Combined Oxidative Phosphorylation Deficiency Type-13 with Perinatal Presentation: A Case Report.

Introduction: Polynucleotide phosphorylase is involved in RNA processing in mitochondria. Biallelic variants in PNPT1 cause mitochondrial RNA import protein deficiency and heterogeneous clinical manifestations.

Case Report: The patiest was the first child of remote consanguineous parents, born at 35 weeks by caesarean section due to fetal growth restriction.

Citrullinemia and What Else?

Introduction: Citrullinemia type I (CTLN1) is a rare autosomal recessive metabolic disorder. Symptoms typically include vomiting, lethargy, seizures and coma. In neonatal presentation, death occurs in days if untreated.

Clinical Presentation of Inherited Metabolic Diseases in Newborns Hospitalised in an Intensive Care Unit.

Background: The first clinical manifestations of inherited metabolic diseases occur in the neonatal period in up to half of cases, often with nonspecific symptoms, making their recognition challenging. This study aimed to characterise inherited metabolic disease cases with neonatal presentation requiring admission to the paediatric intensive care unit in a Portuguese reference centre for inherited metabolic diseases.

Material And Methods: An observational study with retrospective data collection was performed, including all newborns with an inherited metabolic disease admitted to the pediatric intensive care unit between June 2011 and June 2022.

Diversities in Leigh Syndrome Associated with MT-ATP6 Gene Variants.

Introduction: Leigh syndrome (LS) is clinically and genetically heterogeneous and presents defective mitochondrial bioenergetics. Patients present neurological symptoms and imagiological features that may result in early death [1]. The LS has been associated with mitochondrial DNA (mtDNA) variants, e.

GenEye24: Novel rapid screening test for the top-3 Leber's Hereditary Optic Neuropathy pathogenic sequence variants.

Leber's Hereditary Optic Neuropathy (LHON) has been mainly (90-95 %) associated to one of three variants: m.3460G>A, m.11778G>A, m.

Mitochondrial Fatty Acid β-Oxidation Disorders: From Disease to Lipidomic Studies-A Critical Review.

Fatty acid oxidation disorders (FAODs) are inborn errors of metabolism (IEMs) caused by defects in the fatty acid (FA) mitochondrial β-oxidation. The most common FAODs are characterized by the accumulation of medium-chain FAs and long-chain (3-hydroxy) FAs (and their carnitine derivatives), respectively. These deregulations are associated with lipotoxicity which affects several organs and potentially leads to life-threatening complications and comorbidities.

Description of the molecular and clinical characteristics of the mucopolysaccharidosis type VII Iberian cohort.

Background: Mucopolysaccharidosis type VII (Sly syndrome) is an ultra-rare neurometabolic disorder caused by inherited deficiency of the lysosomal enzyme β-glucuronidase. Precise data regarding its epidemiology are scarce, but birth prevalence is estimated to vary from 0.02 to 0.

Plasma Phospholipidomic Profile Differs between Children with Phenylketonuria and Healthy Children.

Phenylketonuria (PKU) is a disease of the catabolism of phenylalanine (Phe), caused by an impaired function of the enzyme phenylalanine hydroxylase. Therapeutics is based on the restriction of Phe intake, which mostly requires a modification of the diet. Dietary restrictions can lead to imbalances in specific nutrients, including lipids.

Phenylketonuria in Portugal: Genotype-phenotype correlations using molecular, biochemical, and haplotypic analyses.

Background: The impairment of the hepatic enzyme phenylalanine hydroxylase (PAH) causes elevation of phenylalanine levels in blood and other body fluids resulting in the most common inborn error of amino acid metabolism (phenylketonuria). Persistently high levels of phenylalanine lead to irreversible damage to the nervous system. Therefore, early diagnosis of the affected individuals is important, as it can prevent clinical manifestations of the disease.

Congenital Disorders of Glycosylation in Portugal-Two Decades of Experience.

Objective: To describe the clinical, biochemical, and genetic features of both new and previously reported patients with congenital disorders of glycosylation (CDGs) diagnosed in Portugal over the last 20 years.

Study Design: The cohort includes patients with an unexplained multisystem or single organ involvement, with or without psychomotor disability. Serum sialotransferrin isoforms and, whenever necessary, apolipoprotein CIII isoforms and glycan structures were analyzed.

Lipids and phenylketonuria: Current evidences pointed the need for lipidomics studies.

Phenylketonuria (PKU) is the most prevalent inborn error of amino acid metabolism. The disease is due to the deficiency of phenylalanine (Phe) hydroxylase activity, which causes the accumulation of Phe. Early diagnosis through neonatal screening is essential for early treatment implementation, avoiding cognitive impairment and other irreversible sequelae.

Experience on statin therapy in paediatric age: retrospective study in a Portuguese referral centre.

Background: The use of statins in children, although not frequent, is recommended in specific clinical contexts, namely, familial hypercholesterolaemia, conditions carrying a moderate-high cardiovascular risk and sub-optimal cholesterol levels after implementation of lifestyle modifications. The aim of this study is to characterise children with dyslipidaemia managed with statins, followed at a tertiary referral centre in central Portugal.

Methods And Results: The authors carried out a retrospective and descriptive study made up of 66 patients (50% males, mean age of therapy onset 11.

Ketogenic Diet for Refractory Childhood Epilepsy: Beyond Seizures Control, the Experience of a Portuguese Pediatric Centre.

Introduction: Ketogenic diet is a low carbohydrate diet, which can be used as a treatment for refractory childhood epilepsy. The first aim of this study was to evaluate its efficacy, in patients receiving ketogenic diet for at least three months, on epilepsy control, behaviour and awareness. The secondary aims were to evaluate the variation in the number of antiepileptic drugs, reasons for discontinuing the diet and adverse effects.

Phenotype, treatment practice and outcome in the cobalamin-dependent remethylation disorders and MTHFR deficiency: Data from the E-HOD registry.

Aim: To explore the clinical presentation, course, treatment and impact of early treatment in patients with remethylation disorders from the European Network and Registry for Homocystinurias and Methylation Defects (E-HOD) international web-based registry.

Results: This review comprises 238 patients (cobalamin C defect n = 161; methylenetetrahydrofolate reductase deficiency n = 50; cobalamin G defect n = 11; cobalamin E defect n = 10; cobalamin D defect n = 5; and cobalamin J defect n = 1) from 47 centres for whom the E-HOD registry includes, as a minimum, data on medical history and enrolment visit. The duration of observation was 127 patient years.

Clinical, neuroradiological, and biochemical features of SLC35A2-CDG patients.

SLC35A2-CDG is caused by mutations in the X-linked SLC35A2 gene encoding the UDP-galactose transporter. SLC35A2 mutations lead to hypogalactosylation of N-glycans. SLC35A2-CDG is characterized by severe neurological symptoms and, in many patients, early-onset epileptic encephalopathy.

Inborn Errors of RNA Lariat Metabolism in Humans with Brainstem Viral Infection.

Viruses that are typically benign sometimes invade the brainstem in otherwise healthy children. We report bi-allelic DBR1 mutations in unrelated patients from different ethnicities, each of whom had brainstem infection due to herpes simplex virus 1 (HSV1), influenza virus, or norovirus. DBR1 encodes the only known RNA lariat debranching enzyme.