Inborn errors of metabolism

The urea cycle disorder carbamoyl phosphate synthetase I deficiency is an important differential diagnosis in the encephalopathic neonate. This intoxication type inborn error of metabolism often leads to neonatal death or severe and irreversible damage of the central nervous system, even despite appropriate treatment. Timely diagnosis is crucial, but can be difficult on routine metabolite level. Here, we report ten neonates from eight families (finally) diagnosed with CPS1 deficiency at three tertiary metabolic centres...

OBJECTIVE: Psychotic disorders in childhood and early adolescence often progress to chronic schizophrenia, but in many cases there are diagnosable medical and genetic causes or risk factors. We reviewed our clinical experience and the relevant literature to identify these factors and to define their clinical features, appropriate work-up and treatment. METHOD: We reviewed the results of comprehensive medical evaluations of 160 psychotic children and adolescents in our center...

INTRODUCTION: Although the overall incidence of inborn errors of metabolism is low, their early diagnosis is essential, since some of them have a specific treatment. DEVELOPMENT: We review the main treatable inborn errors of metabolism that can present as early-onset epileptic encephalopathies, together with their biochemical markers and their treatment. CONCLUSIONS: It is important to think about the possibility of an inborn error of metabolism with a specific therapy, since it is crucial for this to be started as soon as possible in order to prevent permanent neurological damage...

PURPOSE: Inborn Errors of Metabolism (IEMs) are a group of complex genetic conditions, predominantly affecting the pediatric population. While the understanding and identification of various IEMs has significantly improved over recent times, not much is known about the communication disorders in this population. The present study focused on identification and profiling of communication impairments in children diagnosed with IEMs. METHODS: Data was obtained retrospectively from medical records of children visiting a tertiary care hospital over a period of ten years (2005 - 2014)...

Pulmonary alveolar proteinosis is a rare lung disease in which lipoproteinaceous material accumulates within the alveoli, interfering with gas exchange. The disease is classified into congenital, secondary, and acquired. The congenital form includes inborn errors of surfactant metabolism, lysinuric protein intolerance and mutations in the components of granulocyte-macrophage colony-stimulating factor receptor. The main symptoms are non-specific. The radiologic appearance of pulmonary alveolar proteinosis is bilateral, symmetric and perihilar airspace consolidation...

L-Carnitine functions to transport long chain fatty acyl-CoAs into the mitochondria for degradation by β-oxidation. Treatment with L-carnitine can ameliorate metabolic imbalances in many inborn errors of metabolism. In recent years there has been considerable interest in the therapeutic potential of L-carnitine and its acetylated derivative acetyl-L-carnitine (ALCAR) for neuroprotection in a number of disorders including hypoxia-ischemia, traumatic brain injury, Alzheimer's disease and in conditions leading to central or peripheral nervous system injury...

Inborn errors of metabolism (IEM) are rare individually, but taken together, they affect 1 in 1,000 people. Most of the disease becomes apparent at the pediatric age; however, with the identification of late-onset forms, and with improved survival, several of these conditions may be found in adults of all ages. While the lung is not typically a primary site of clinical disease in patients with IEM, in some of them it can be a significantly affected organ with associated severe respiratory complications. Lung involvement can be a late- onset feature of a complex multisystemic disease, but sometimes it can also be the only manifestation of underlying IEM...

The hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHN) are distinct pulmonary vascular complications of portal hypertension (PHT) and are associated with increased morbidity and mortality. OBJECTIVES: To describe the clinical and laboratory characteristics of patients with pulmonary hypertension and pulmonary vascular complications hospitalized at the Instituto Nacional de Salud del Niño. MATERIALS AND METHODS: We included patients with HTP hospitalized from January 2012 to June 2013 and that during its evolution progressed with SHP or HTPP...

Mutations in the cystathionine beta-synthase (CBS) gene are the cause of classical homocystinuria, the most common inborn error in sulfur metabolism. The c.797 G>A (p.R266K) mutation in CBS was originally described in several Norwegian pyridoxine responsive CBS deficient patients, and heterologous gene expression studies have shown that the protein has near wild-type levels of enzyme activity. Here, we characterize a transgenic mouse lacking endogenous Cbs and expressing p.R266K human CBS protein from a zinc inducible metallothionein promoter (Tg-R266K Cbs-/-)...

Lysosomal storage diseases (LSD) are inborn errors of metabolism resulting in multisystem disease. Central nervous system involvement, often with progressive neurodegeneration, accounts for a large portion of the morbidity and mortality seen in many LSD. Available treatments fail to prevent or correct neurologic symptoms and decline. Emerging evidence points to an important role for mitochondrial dysfunction in the pathogenesis and progression of LSD-associated neurodegeneration. Mitochondrial dysfunction in LSD is characterized by alterations in mitochondrial mass, morphology and function...

BACKGROUND: Inborn errors of metabolism (IEMs) underlie a substantial proportion of paediatric disease burden but their genetic diagnosis can be challenging using the traditional approaches. METHODS: We designed and validated a next-generation sequencing (NGS) panel of 226 IEM genes, created six overlapping phenotype-based subpanels and tested 102 individuals, who presented clinically with suspected childhood-onset IEMs. RESULTS: In 51/102 individuals, NGS fully or partially established the molecular cause or identified other actionable diagnoses...

Historically, d-glyceric aciduria was thought to cause an uncharacterized blockage to the glycine cleavage enzyme system (GCS) causing nonketotic hyperglycinemia (NKH) as a secondary phenomenon. This inference was reached based on the clinical and biochemical results from the first d-glyceric aciduria patient reported in 1974. Along with elevated glyceric acid excretion, this patient exhibited severe neurological symptoms of myoclonic epilepsy and absent development, and had elevated glycine levels and decreased glycine cleavage system enzyme activity...

The Inborn Errors of Metabolism Collaborative (IBEMC) includes clinicians from 29 institutions collecting data to enhance understanding of metabolic conditions diagnosable by newborn screening. Data collected includes hospitalizations, test results, services, and long-term outcomes. Through evaluation of this data, we sought to determine how frequently genetic counseling had been provided, how often genetic testing was performed, and also determine the consanguinity rate in this population. A data query was performed with the following elements abstracted/analyzed: current age, metabolic condition, whether genetic counseling was provided (and by whom), whether genetic testing was performed, and consanguinity...

CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription...

BACKGROUND: Phenylketonuria (PKU) is an inborn error of metabolism characterized by increased blood concentrations of phenylalanine (Phe). OBJECTIVES: The aim of the present study was to assess the association between the metabolic compliance of adult patients affected by classic PKU and the characteristics of their present and past occupations. METHODS: The study population consisted of working adults, affected by classic PKU, and following a dietary treatment...

BACKGROUND: Neonatal seizures can be the first symptom of the inborn errors of metabolism. Glucose transporter type 1 deficiency syndrome (GLUT1DS) is the result of impaired glucose transport into the brain. GLUT1DS patient presents with infantile seizures with resistant to traditional seizure medications, developmental delay, acquired microcephaly, spasticity and ataxia. CASE REPORT: Here, we report a rare case of Glucose transporter type 1 deficiency syndrome caused by a different pathogenic variant in a 10-day-old neonate who presented with intractable seizures and respiratory arrest...

Amino acids (AAs) support a broad range of functions in living organisms, including several that affect the immune system. The functions of the immune system are affected when free AAs are depleted or in excess because of external factors, such as starvation, or because of genetic factors, such as inborn errors of metabolism. Areas covered: In this review, we discuss the current insights into how free AAs affect immune responses. When possible, we make comparisons to known disease states resulting from inborn errors of metabolism, in which changed levels of AAs or AA metabolites provide insight into the impact of AAs on the human immune system in vivo...

3-Methylglutaconic aciduria is a member of inborn errors of leucine metabolism pathway. 3-Methylglutaconic aciduria type I (MGA1) causes neurological problems which are present during infancy or childhood but the diagnosis may be delayed until adulthood. Here we report a 3years old patient with developmental delay from a relative parent's that his medical evaluations include analyses of urinary organic acid and blood acylcarnitine showed high level of 3-methylglutacoic acid, 3-hydroxyisovaleric acid and increased level of 3-hydroxyisovalerylcarnitine respectively...

OBJECTIVES: To describe the epidemiological features, clinical characteristics and outcomes of neonates diagnosed with liver failure, as well as determine prognostic factors. METHODS: Cohort study conducted at a single tertiary referral and university-affiliated pediatric center. Hospital records of all neonates diagnosed with liver failure between January 2003 and December 2015 were retrospectively reviewed, and data on clinical and laboratory findings, treatment, and outcomes were collected...

Tissue accumulation of α-ketoadipic (KAA) and α-aminoadipic (AAA) acids is the biochemical hallmark of α-ketoadipic aciduria. This inborn error of metabolism is currently considered a biochemical phenotype with uncertain clinical significance. Considering that KAA and AAA are structurally similar to α-ketoglutarate and glutamate, respectively, we investigated the in vitro effects of these compounds on glutamatergic neurotransmission in the brain of adolescent rats. Bioenergetics and redox homeostasis were also investigated because they represent fundamental systems for brain development and functioning...