Amino Acid Metabolism and Immune Dysfunction in Urea Cycle Disorders: T and B Cell Perspectives.

Urea cycle disorders (UCDs) are a group of genetic metabolic conditions characterized by enzyme deficiencies responsible for detoxifying ammonia. Hyperammonemia, the accumulation of intermediate metabolites, and a deficiency of essential amino acids-due to a protein-restrictive diet and the use of ammonia scavengers-can increase the risk of infections, particularly during metabolic crises. While the underlying mechanisms of immune suppression are still being fully elucidated, hyperammonemia may impair the function of immune cells, particularly T cells and macrophages, inhibiting the proliferation of T cells and cytokine production.

Exploring congenital sucrase-isomaltase deficiency in autism spectrum disorder patients with irritable bowel syndrome symptoms: A prospective SI gene sequencing study.

Congenital sucrase-isomaltase deficiency (CSID) is an inherited metabolic disorder causing chronic gastrointestinal symptoms and malnutrition when untreated. Most CSID patients are likely to remain under- or misdiagnosed. This study aimed to investigate prevalence of CSID among patients with autism spectrum disorder (ASD) presenting with irritable bowel syndrome (IBS) symptoms via prospective SI gene sequencing.

A New Perspective On Arterioectatic Spinal Angiopathy with a Reversible Pattern: Cause or Consequence?

Objective: In 2022, arterioectatic spinal angiopathy (AESA) of childhood was reported as a fatal, progressive, multi-segment myelopathy associated with a unique form of non-inflammatory spinal angiopathy involving diffuse dilatation of the anterior spinal artery and cord congestion in children. In this study, we present four more cases of AESA, using early and long-term conventional imaging and flat detector computed tomography angiography (FDCTA) imaging to assess the probability of disease regression and prevent unnecessary interventions.

Methods: We retrospectively reviewed the clinical and radiological findings of four patients with AESA seen in two neuroradiology departments between 2014 and 2023.

Emerging trends in pediatric candidemia: mapping the rise in Candida parapsilosis incidence and antifungal resistance in Turkey.

Candidemia is emerging as a significant concern in children, particularly among those with underlying conditions like malignancies or prematurity. The interpretation of epidemiological data on candidemias and their antifungal resistance plays a vital role in aiding diagnosis and guiding clinicians in treatment decisions. From 2014 to 2021, a retrospective analysis was conducted in İstanbul, Turkey; comparing Candida albicans and non-albicans (NAC) spp in both surviving and deceased groups.

A Novel Homozygous Variant in an Emerging Peroxisomal Disorder Presenting with Retinal Dystrophy and a Review of the Literature.

Introduction: Acyl-CoA binding domain containing 5 (ACBD5) deficiency is a newly defined inborn peroxisomal disorder with only 7 patients reported to date. Herein, we report a patient with ACBD5 deficiency who was diagnosed after a complicated diagnostic process.

Case Presentation: A 6-year-old male patient was admitted with complaints of neuromotor regression and visual disturbances.

Comparison of Cost Analysis in Patients with Tetrahydrobiopterin-Responsive and Non-Responsive Phenylketonuria in Turkey.

Phenylketonuria is an inherited metabolic disorder that leads to neurobehavioral dysfunction. The main treatment is a low-phenylalanine diet and/or the cofactor tetrahydrobiopterin. Regular outpatient follow-up care and measurement of the phenylalanine levels in the blood are required.

Clinical, biochemical, and molecular insights into Cerebrotendinous Xanthomatosis: A nationwide study of 100 Turkish individuals.

Objective: Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey.

Methods: The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed.

Pteridine and tryptophan pathways in children with type 1 diabetes: Isoxanthopterin as an indicator of endothelial dysfunction.

Aim: Type 1 diabetes (T1D) and its complications are known to be associated with oxidative stress. Pteridine derivatives and indoleamine 2,3-dioxygenase (IDO) activity can be used as biomarkers in the evaluation of oxidative stress. In this study, our aim is to compare the concentrations of serum and urinary pteridine derivatives, as well as serum IDO activity, in children and adolescents diagnosed with T1D and those in a healthy control group.

Serum Neopterin, Biopterin, Tryptophan, and Kynurenine Levels in Patients with Fabry Disease.

Background: Fabry disease is characterized by the accumulation of globotriaosylceramide. Substrate accumulation in lysosomes is thought to trigger an inflammatory response and is responsible for progressive organ damage through the induction of autoimmunity. The levels of pteridine and kynurenine pathway metabolites increase when immune activation is observed and are employed to monitor several diseases and determine prognosis.

Autism Spectrum Disorder in Two Unrelated Patients with Homozygous Variants in Either ALG8 or ALG11.

Background: Autism spectrum disorder (ASD) is used to describe individuals with a specific combination of disorders in social communication and repetitive behaviors, highly restricted interests, and/or sensory behavior that begin early in life. The prevalence of ASD has been increasing rapidly in recent years. Pathophysiology of ASDs remains still unclear; however, genetic defects and multifactorial causes have been reported to play an important role in genetic disorders.

Analysis of Biotinidase Activity in Serum by Digital Imaging Colorimetry Detection.

Biotinidase deficiency (BD) is an autosomal recessive inherited disorder of biotin recycling that leads to neurological and cutaneous consequences if left untreated. The clinical features of BD can be ameliorated or prevented by the administration of pharmacological doses of the vitamin biotin. Since it is a treatable disorder, BD is included in the newborn screening program in Türkiye as in many other countries.

Urinary neopterin and biopterin indicate that inflammation has a role in autism spectrum disorder.

Inflammation is thought to be involved in the pathogenesis of autism spectrum disorder (ASD). Pteridine metabolites are biomarkers of inflammation that increase on immune system activation. In this study, we investigated the urinary pteridine metabolites in ASD patients as a possible biomarker for immune activation and inflammation.

A Methionine-Portioning-Based Medical Nutrition Therapy with Relaxed Fruit and Vegetable Consumption in Patients with Pyridoxine-Nonresponsive Cystathionine-β-Synthase Deficiency.

The main treatment for pyridoxine-nonresponsive cystathionine-β-synthase deficiency is a strict diet. Most centers prescribe low-protein diets based on gram-protein exchanges, and all protein sources are weighed. The purpose of this study is to investigate the effects of a more liberal methionine (Met)-based diet with relaxed consumption of fruits and vegetables on metabolic outcomes and dietary adherence.

Separation and quantification of the urinary enantiomers of 2-hydroxyglutaric acid by capillary electrophoresis with capacitively coupled contactless conductivity detection: Application to the diagnosis of D- and L-2-hydroxyglutaric aciduria.

2-hydroxyglutaric aciduria is an inherited neurometabolic disorder with two major types: D-2-hydroxyglutaric aciduria and L-2-hydroxyglutaric aciduria. An easy and fast capillary electrophoresis system combined with a capacitively coupled contactless conductivity detection method was developed for the enantioseparation and determination of D- and L-2-hydroxyglutaric acid in urine. D- and L-2-hydroxyglutaric acids were separated using vancomycin as the chiral selector.

BNT162b2 COVID-19 vaccination elicited protective robust immune responses in pediatric patients with inborn errors of metabolism.

Introduction: SARS-CoV-2 infection can lead to a life-threatening acute metabolic decompensation in children with inborn errors of metabolism (IEM), so vaccination is mandatory. However, IEMs can also impair innate or adaptive immunity, and the impact of these immune system alterations on immunogenicity and vaccine efficacy is still unknown. Here, we investigated humoral immune responses to the BNT162b2 mRNA COVID-19 vaccine and clinical outcomes in pediatric IEM patients.

Three-Country Snapshot of Ornithine Transcarbamylase Deficiency.

X-linked ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle defect. The disease severity ranges from asymptomatic carrier state to severe neonatal presentation with hyperammonaemic encephalopathy. We audited the diagnosis and management of OTCD, using an online 12-question-survey that was sent to 75 metabolic centres in Turkey, France and the UK.

Evaluation of plasma carnitine status in patients diagnosed with juvenile idiopathic arthritis.

Background: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood and manifests mainly as autoinflammation of the joints and other tissues. Several treatment options such as nonsteroidal antiinflammatory drugs, methotrexate, and intra-articular steroids are widely used to relieve and improve this inflammation. Secondary carnitine deficiency can be detected in chronic diseases by either renal loss or increased demand.

Safety of COVID-19 vaccines in children with inborn errors of metabolism in terms of developing metabolic decompensation.

Aim: There are no recommended guidelines or clinical studies on safety of COVID-19 vaccines in patients with inborn errors of metabolism (IEMs). Here, we aimed to examine the relationship between COVID-19 vaccination and metabolic outcome in paediatric IEM patients.

Methods: Patients with IEM between the ages of 12 and 18 were enrolled.

Altered immune response in organic acidemia.

Background: Most patients with organic acidemia suffer from recurrent infections. Although neutropenia has been reported in multiple studies, other components of the immune system have not been evaluated thoroughly. This study was conducted to assess the immune status of patients with organic acidemia (OA).

Evaluation of dynamic thiol/disulfide homeostasis in hereditary tyrosinemia type 1 patients.

Background: Despite successful treatment with nitisinone, the pathophysiology of long-term complications, including hepatocellular carcinoma and mental decline in tyrosinemia type 1 patients, is still obscure. Oxidative stress may play a role in these complications. While increased fumarylacetoacetate and maleylacetoacetate cause oxidative stress in the liver, increased tyrosine causes oxidative stress in the brain.

COVID-19 triggered encephalopathic crisis in a patient with glutaric aciduria type 1.

Objectives: The impact of coronavirus disease-19 (COVID-19) on metabolic outcome in patients with inborn errors of metabolism has rarely been discussed. Herein, we report a case with an acute encephalopathic crisis at the course of COVID-19 disease as the first sign of glutaric aciduria type 1 (GA-1).

Case Presentation: A 9-month-old patient was admitted with encephalopathy and acute loss of acquired motor skills during the course of COVID-19 disease.

Postural tremor in L-2-hydroxyglutaric aciduria is associated with cerebellar atrophy.

Objective: In this study, we performed analysis of brainstem reflexes and movement disorders using surface polymyogram in L-2-hydroxyglutaric aciduria (L2HGA). We also reviewed all cases in the literature with detailed clinical and radiological description to analyze the anatomical correlates of involuntary movements.

Patients And Method: We performed surface electromyography of appropriate muscles, long-loop reflexes, and somatosensory evoked potentials and analyzed the neuroimaging findings in patients with L2HGA and recorded blink reflex (BR), auditory startle response (ASR), and startle response after somatosensory stimuli (SSS) in patients and healthy subjects.