The continuously evolving phenotype of succinic semialdehyde dehydrogenase deficiency.

The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia.

Expert-opinion-based guidance for the care of children with lysosomal storage diseases during the COVID-19 pandemic: An experience-based Turkey perspective.

This expert-opinion-based document was prepared by a group of specialists in pediatric inherited metabolic diseases and infectious diseases including administrative board members of Turkish Society for Pediatric Nutrition and Metabolism to provide guidance for the care of children with lysosomal storage disorders (LSDs) during the COVID-19 pandemic in Turkey. The experts reached consensus on key areas of focus regarding COVID-19-based risk status in relation to intersecting immune-inflammatory mechanisms and disease patterns in children with LSDs, diagnostic virus testing, particularly preventive measures and priorities during the pandemic, routine screening and diagnostic interventions for LSDs, psychological and socioeconomic impact of confinement measures and quarantines and optimal practice patterns in managing LSDs and/or COVID-19. The participating experts agreed on the intersecting characteristics of immune-inflammatory mechanisms, end-organ damage and prognostic biomarkers in LSD and COVID-19 populations, emphasizing the likelihood of enhanced clinical care when their interaction is clarified further studies addressing certain aspects related to immunity, lysosomal dysfunction and disease pathogenesis.

Organic acidemias in the neonatal period: 30 years of experience in a referral center for inborn errors of metabolism.

Objectives: Neonatal-onset organic acidemias (OAs) account for 80% of neonatal intensive care unit (NICU) admissions due to inborn errors of metabolism. The aim of this study is to analyze clinical features and follow-up of neonates diagnosed with OAs in a metabolic referral center, focusing on perinatal characteristics and the impact of first the metabolic crisis on long-term outcome.

Methods: Perinatal features, clinical and laboratory characteristics on admission and follow-up of 108 neonates diagnosed with OAs were retrospectively analyzed.

Management of early treated adolescents and young adults with phenylketonuria: Development of international consensus recommendations using a modified Delphi approach.

Background: Early treated patients with phenylketonuria (PKU) often become lost to follow-up from adolescence onwards due to the historical focus of PKU care on the pediatric population and lack of programs facilitating the transition to adulthood. As a result, evidence on the management of adolescents and young adults with PKU is limited.

Methods: Two meetings were held with a multidisciplinary international panel of 25 experts in PKU and comorbidities frequently experienced by patients with PKU.

Single Institutional Experience with GM1 Gangliosidosis: Clinical and Laboratory Results of 14 Patients.

Background: GM1 gangliosidosis is an autosomal recessive lysosomal storage disease caused by biallelic mutations in the gene. Neurodegeneration, hypotonia, visceromegaly, macular cherry-red spots, skeletal dysplasia, and coarse and dysmorphic face are the major clinical features.

Aims: To evaluate the demographic and clinical data of patients with GM1 gangliosidosis in a single center.

Recommendations on phenylketonuria in Turkey.

Background: Phenylketonuria (PKU), is an autosomal recessive disease leading to the conversion defect of phenylalanine (Phe) into tyrosine. Severe neurocognitive and behavioral outcomes are observed in untreated cases. The present paper aims to review clinical experiences and expert recommendations in diagnosis, treatment, and follow-up of pediatric PKU patients in Turkey.

Liver-Directed Adeno-Associated Virus-Mediated Gene Therapy for Mucopolysaccharidosis Type VI.

BACKGROUND: Mucopolysaccharidosis type VI (MPS VI) is an inherited multisystem lysosomal disorder due to arylsulfatase B (ARSB) deficiency that leads to widespread accumulation of glycosaminoglycans (GAG), which are excreted in increased amounts in urine. MPS VI is characterized by progressive dysostosis multiplex, connective tissue and cardiac involvement, and hepatosplenomegaly. Enzyme replacement therapy (ERT) is available but requires life-long and costly intravenous infusions; moreover, it has limited efficacy on diseased skeleton and cardiac valves, compromised pulmonary function, and corneal opacities.

Splenic Gaucheroma Leading to Incidental Diagnosis of Gaucher Disease in a 46-Year-Old Man with a Rare GBA Mutation: A Case Report.

Background: Gaucher disease is a common lysosomal storage disease caused by the deficiency of the β-glucosidase enzyme, leading to sphingolipid accumulation in the reticuloendothelial system in Gaucher cells. Clinical findings are quite variable and some patients may remain asymptomatic lifelong. However, even when patients have mild symptoms, there is a significant increase in their quality of life with enzyme replacement therapy.

Hyperinsulinism May Be Underreported in Hypoglycemic Patients with Phosphomannomutase 2 Deficiency.

Objective: Phosphomannomutase 2 deficiency (PMM2-CDG) is a disorder of protein N-glycosylation with a wide clinical spectrum. Hypoglycemia is rarely reported in PMM2-CDG. In this study, we evaluated cause, treatment options and outcomes in cases with hypoglycemia in the course of PMM2-CDG.

Difficulties Associated with Enzyme Replacement Therapy for Mucopolysaccharidoses.

Background: Mucopolysaccharidoses are extremely rare, progressive, often severe multisystem disorders, some of which are managed by weekly intravenous enzyme replacement therapy. This study aimed to determine the difficulties faced by the patients with mucopolysaccharidosis and their families due to enzyme replacement therapy.

Methods: A questionnaire about demographics, enzyme replacement therapy-related characteristics, and specific enzyme replacement therapy-related difficulties was conducted over the telephone with mucopolysaccharidosis patients (or their parents) followed at a referral center in Turkey, who have been on enzyme replacement therapy for ≥12 months.

A non-interventional observational study to identify and validate clinical outcome assessments for adults with phenylketonuria for use in clinical trials.

Introduction: Current clinical outcome assessments (COAs) are not effectively capturing the complex array of symptoms of adults with phenylketonuria (PKU). This study aimed to identify concepts of interest relevant to adults with PKU. Based on these concepts, COAs for patient-reported outcomes (PROs), observer-reported outcomes (ObsROs), and clinician-reported outcomes (ClinROs) were selected or developed and content validity was assessed.

COVID-19-related anxiety in phenylketonuria patients.

Background: Phenylketonuria (PKU) is an inherited disorder of amino acid metabolism, the treatment of which often requires a special diet to prevent adverse neuropsychiatric outcomes. In the COVID-19 pandemic, which has had a substantial effect on the whole world since the beginning of 2020, PKU patients represent a vulnerable population because they may be dependent on special nutritional products, have limited access to routine care and display increased levels of anxiety.

Methods: For this reason, an online questionnaire assessing the anxiety levels and various personal opinions and practices regarding the pandemic was sent to the PKU patients managed at our clinic, who were 12 years of age or older.

Insights into the expanding phenotypic spectrum of inherited disorders of biogenic amines.

Inherited disorders of neurotransmitter metabolism are rare neurodevelopmental diseases presenting with movement disorders and global developmental delay. This study presents the results of the first standardized deep phenotyping approach and describes the clinical and biochemical presentation at disease onset as well as diagnostic approaches of 275 patients from the registry of the International Working Group on Neurotransmitter related Disorders. The results reveal an increased rate of prematurity, a high risk for being small for gestational age and for congenital microcephaly in some disorders.

Clinical and molecular characteristics of carnitineacylcarnitine translocase deficiency with c.270delC and a novel c.408C>A variant.

Background: Carnitine-acylcarnitine translocase deficiency (CACTD) is a rare, autosomal recessive, and highly lethal fatty acid oxidation (FAO) disorder caused by defective acylcarnitine transport across the mitochondrial membrane. CACTD is characterized by severe episodes of hypoglycemia and hyperammonemia, seizures, cardiomyopathy, liver dysfunction, severe neurological damage, and muscle weakness. Herein, we described the clinical features, biochemical, and molecular findings of three patients with CACTD, presented with poor feeding, hypoglycemia, liver dysfunctions, and hyperammonemia, but died despite intensive treatment.

Long-term efficacy and safety of sapropterin in patients who initiated sapropterin at < 4 years of age with phenylketonuria: results of the 3-year extension of the SPARK open-label, multicentre, randomised phase IIIb trial.

Background: During the initial 26-week SPARK (Safety Paediatric efficAcy phaRmacokinetic with Kuvan®) study, addition of sapropterin dihydrochloride (Kuvan®; a synthetic formulation of the natural cofactor for phenylalanine hydroxylase, tetrahydrobiopterin; BH), to a phenylalanine (Phe)-restricted diet, led to a significant improvement in Phe tolerance versus a Phe-restricted diet alone in patients aged 0-4 years with BH-responsive phenylketonuria (PKU) or mild hyperphenylalaninaemia (HPA). Based on these results, the approved indication for sapropterin in Europe was expanded to include patients < 4 years of age. Herein, we present results of the SPARK extension study (NCT01376908), evaluating the long-term safety, dietary Phe tolerance, blood Phe concentrations and neurodevelopmental outcomes in patients < 4 years of age at randomisation, over an additional 36 months of treatment with sapropterin.

Assessment of intellectual impairment, health-related quality of life, and behavioral phenotype in patients with neurotransmitter related disorders: Data from the iNTD registry.

Inherited disorders of neurotransmitter metabolism are a group of rare diseases, which are caused by impaired synthesis, transport, or degradation of neurotransmitters or cofactors and result in various degrees of delayed or impaired psychomotor development. To assess the effect of neurotransmitter deficiencies on intelligence, quality of life, and behavior, the data of 148 patients in the registry of the International Working Group on Neurotransmitter Related Disorders (iNTD) was evaluated using results from standardized age-adjusted tests and questionnaires. Patients with a primary disorder of monoamine metabolism had lower IQ scores (mean IQ 58, range 40-100) within the range of cognitive impairment (<70) compared to patients with a BH deficiency (mean IQ 84, range 40-129).

Correction to: DNAJC12 deficiency in patients with unexplained hyperphenylalaninemia: two new patients and a novel variant.

A Correction to this paper has been published: https://doi.org/10.1007/s11011-021-00759-8.

DNACJ12 deficiency in patients with unexplained hyperphenylalaninemia: two new patients and a novel variant.

In addition to tetrahydrobiopterin deficiencies and phenylalanine hydroxylase deficiency (phenylketonuria) due to PAH variants, the deficiency of the co-chaperone protein DNAJC12 was identified in 2017 as a novel cause of inherited hyperphenylalaninemia, revealing the genetic etiology in previously unresolved cases. In this study, we aimed to investigate DNAJC12 deficiency in non-tetrahydrobiopterin-deficient persistent hyperphenylalaninemia cases without biallelic PAH variants in a single pediatric metabolic center. It was determined retrospectively that 471 patients with non-tetrahydrobiopterin deficiency-hyperphenylalaninemia had undergone PAH gene sequencing and 451 patients had biallelic variants in PAH.

Complicated peripartum course in a patient with very long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency.

Very long-chain acyl-coenzyme A (CoA) dehydrogenase (VLCAD) deficiency is an autosomal recessive fatty acid oxidation disorder characterized by rhabdomyolysis, hypoglycemia and cardiomyopathy. The general treatment approach in adult patients is based on the prevention of catabolism. High carbohydrate, low fat diet and supplementation of medium-chain triglycerides are essential in the treatment.

Sensory, voluntary, and motor postural control in children and adolescents with mucopolysaccharidosis.

Objectives: This study aimed to investigate automatic and voluntary motor control performances, which have an important function in maintaining balance, in children and adolescents with mucopolysaccharidosis (MPS).

Methods: The records of 70 patients were retrospectively analyzed. The results of Computerized Dynamic Posturography (CDP) performed according to the age and development of the individuals were examined.

Invisible burden of COVID-19: enzyme replacement therapy disruptions.

Objectives: Lysosomal storage diseases (LSD) constitute an important group of metabolic diseases, consisting of approximately 60 disorders. In some types of lysosomal diseases, enzyme replacement therapy (ERT) is administered intravenously in weekly or biweekly doses. Unfortunately, scheduled ERT during COVID-19 was disrupted.

Brain MR patterns in inherited disorders of monoamine neurotransmitters: An analysis of 70 patients.

Inherited monoamine neurotransmitter disorders (iMNDs) are rare disorders with clinical manifestations ranging from mild infantile hypotonia, movement disorders to early infantile severe encephalopathy. Neuroimaging has been reported as non-specific. We systematically analyzed brain MRIs in order to characterize and better understand neuroimaging changes and to re-evaluate the diagnostic role of brain MRI in iMNDs.

Oral health status of children and young adults with maple syrup urine disease in Turkey.

Background: Maple syrup urine disease (MSUD) is an inherited disorder clinically characterized by ketoacidosis, seizures, coma, psychomotor delay, and intellectual disability. The treatment requires a life-long protein-restricted diet, rich in carbohydrates and fats, supplemented with a medical amino acid formula. Diet, oral health and general health influence each other in a vicious cycle.

Glutaric aciduria type 1: Genetic and phenotypic spectrum in 53 patients.

Introduction: Glutaric aciduria type 1 (GA1) is a rare and inherited autosomal-recessive metabolic disorder that occurs in the deficiency of glutaryl-co-enzyme A dehydrogenase (GCDH) enzyme encoded by GCDH gene. In this study, we aim to retrospectively investigate the clinical, biochemical, and neuroradiological parameters and examine the spectrum of GCDH gene variants in Turkish patients with glutaric aciduria type 1.

Methods: This is a descriptive cross-sectional study.