Safety and effectiveness of ataluren in patients with Duchenne muscular dystrophy: single-center experience from Saudi Arabia.

Objective: Duchenne muscular dystrophy (DMD) is a rare X-linked neurodegenerative disorder caused by mutations in the gene. This study examined the efficacy and safety of ataluren, the first oral treatment for DMD with nonsense mutations (nmDMD), in patients in the Middle East.

Methods: This retrospective longitudinal study assessed the outcomes of seven boys with nmDMD who received treatment with ataluren and follow-up at a single center since 2016.

Liver transplantation in ornithine transcarbamylase deficiency: A retrospective multicentre cohort study.

Ornithine transcarbamylase deficiency (OTCD) is an X-linked defect of ureagenesis and the most common urea cycle disorder. Patients present with hyperammonemia causing neurological symptoms, which can lead to coma and death. Liver transplantation (LT) is the only curative therapy, but has several limitations including organ shortage, significant morbidity and requirement of lifelong immunosuppression.

Diagnostic and Management Issues in Patients with Late-Onset Ornithine Transcarbamylase Deficiency.

Ornithine transcarbamylase deficiency (OTCD) is the most common inherited disorder of the urea cycle and, in general, is transmitted as an X-linked recessive trait. Defects in the OTC gene cause an impairment in ureagenesis, resulting in hyperammonemia, which is a direct cause of brain damage and death. Patients with late-onset OTCD can develop symptoms from infancy to later childhood, adolescence or adulthood.

Genetic Therapy Approaches for Ornithine Transcarbamylase Deficiency.

Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder with high unmet needs, as current dietary and medical treatments may not be sufficient to prevent hyperammonemic episodes, which can cause death or neurological sequelae. To date, liver transplantation is the only curative choice but is not widely available due to donor shortage, the need for life-long immunosuppression and technical challenges. A field of research that has shown a great deal of promise recently is gene therapy, and OTCD has been an essential candidate for different gene therapy modalities, including AAV gene addition, mRNA therapy and genome editing.

Prolonged respiratory failure responds to conventional therapy in isolated homocysteine remethylation defects.

Isolated remethylation defects are rare inherited diseases caused by a defective remethylation of homocysteine to methionine, preventing various essential methylation reactions to occur. Patients present with a systemic phenotype, which can especially affect the central and peripheral nervous systems leading to epileptic encephalopathy, developmental delay and peripheral neuropathy. Respiratory failure has been described in some cases, caused by both central and peripheral neurological involvement.

Expanding the phenotypic landscape of Gaucher disease type 3c with a novel entity - Transient neonatal cholestasis.

Gaucher disease (GD) is the most frequent lysosomal storage disorder due to biallelic pathogenic variants in GBA gene. Only homozygous D409H variant has been associated with the cardiovascular phenotype which is also known as Gaucher disease type 3c. In this descriptive study, we presented phenotypic heterogeneity and a novel clinical finding among 13 patients with GD type 3c.

Targeting the liver to treat the eye.

Over the last two decades, gene therapy has given hope of potential cure for many rare diseases. In the simplest form, gene therapy is the transfer or editing of a genetic material to cure a disease via nonviral or viral vehicles. Gene therapy can be performed either in vivo by injecting a vector carrying the gene or tools for gene editing directly into a tissue or into the systemic circulation, or ex vivo when patient cells are genetically modified outside of the body and then introduced back into the patient (Yilmaz et al, 2022).

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 bone health in patients with mucopolysaccharidosis.

Introduction: This study aimed to evaluate the relationship between clinical findings, height and weight standard deviation scores, 25-hydroxyvitamin D (25(OH)D) level, and dual-energy X-ray absorptiometry (DXA) results in patients diagnosed with mucopolysaccharidosis (MPS), where effective current treatments such as enzyme replacement therapy (ERT) can be accessed.

Materials And Methods: 25(OH)D level was measured in 126 patients with MPS (17 with MPS I, 14 with MPS II, 18 with MPS III, 33 with MPS IVA, and 44 with MPS VI; 24-524 months). DXA was performed in 45 of these patients (8 with MPS I, 4 with MPS II, 4 with MPS III, 12 with MPS IVA, and 17 with MPS VI; 62-197 months; all patients were under 18 when DXA was performed) to assess bone mineral density (BMD) of the lumbar spine.

Niemann-Pick type C disease with a novel intronic mutation: three Turkish cases from the same family.

Objectives: Niemann-Pick type C (NPC) disease is a rare progressive neurodegenerative condition that is characterized by the accumulation of cholesterol, glycosphingolipids, and sphingosine in lysosomes. Patients have various systemic and neurological findings depending on their age at onset. This disease is caused by the autosomal recessive transmission of mutations in the and genes; patients have mutations mainly in the gene (95%) and the majority of them are point mutations located in the exonic regions.

Brown Vialetto Van Laere syndrome: presenting with left ventricular non-compaction and mimicking mitochondrial disorders.

Background: Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare, treatable neurodegenerative disorder with a variable clinical presentation, caused by mutations in three different riboflavin transporter genes.

Case: An 11-year-old-boy presented with respiratory insufficiency and a rapidly progressive muscle weakness. He was the fifth child of a consanguineous marriage with a medical history of hearing loss.

The outcome of 41 Late-Diagnosed Turkish GA-1 Patients: A Candidate for the Turkish NBS.

Background: Glutaric aciduria type 1(GA-1) is an inherited cerebral organic aciduria. Untreated patients with GA-1 have a risk of acute encephalopathic crises during the first 6 years of life. In so far as GA-1 desperately does not exist in Turkish newborn screening (NBS) program, most patients in our study were late-diagnosed.

Gene therapy for inherited metabolic diseases.

Over the last two decades, gene therapy has been successfully translated to many rare diseases. The number of clinical trials is rapidly expanding and some gene therapy products have now received market authorisation in the western world. Inherited metabolic diseases (IMD) are orphan diseases frequently associated with a severe debilitating phenotype with limited therapeutic perspective.

Clinical and molecular findings in 37 Turkish patients with isolated methylmalonic acidemia.

Background/aim: Isolated methylmalonic acidemia (MMA) is caused by complete or partial deficiency of the enzyme methylmalonyl- CoA mutase (mut0 or mut– enzymatic subtype), a defect of its cofactor adenosyl-cobalamin (cblA, cblB, or cblD-MMA), or deficiency of the enzyme methylmalonyl-CoA epimerase. While onset of the disease ranges from the neonatal period to adulthood, most cases present with lethargy, vomiting and ketoacidosis in the early infancy. Major secondary complications are; growth failure, developmental delay, interstitial nephritis with progressive renal failure, basal ganglia injury and cardiomyopathy.

Novel therapies for mucopolysaccharidosis type III.

Mucopolysaccharidosis type III (MPS III) or Sanfilippo disease is an orphan inherited lysosomal storage disease and one of the most common MPS subtypes. The classical presentation is an infantile-onset neurodegenerative disease characterised by intellectual regression, behavioural and sleep disturbances, loss of ambulation, and early death. Unlike other MPS, no disease-modifying therapy has yet been approved.

Clinical and Molecular Features of Early Infantile Niemann Pick Type C Disease.

Niemann Pick disease type C (NPC) is a neurovisceral disorder due to mutations in or . This review focuses on poorly characterized clinical and molecular features of early infantile form of NPC (EIF) and identified 89 cases caused by (NPC1) and 16 by (NPC2) mutations. Extra-neuronal features were common; visceromegaly reported in 80/89 NPC1 and in 15/16 NPC2, prolonged jaundice in 30/89 NPC1 and 7/16 NPC2.

Clinical features of 27 Turkish Propionic acidemia patients with 12 novel mutations.

Kör D, Şeker-Yılmaz B, Bulut FD, Kılavuz S, Öktem M, Ceylaner S, Yıldızdaş D, Önenli-Mungan N. Clinical features of 27 Turkish Propionic acidemia patients with 12 novel mutations. Turk J Pediatr 2019; 61: 330-336.

Four Gaucher disease type II patients with three novel mutations: a single centre experience from Turkey.

Gaucher disease is the most common lysosomal storage disorder due to glucosylceramidase enzyme deficiency. There are three subtypes of the disease. Neurological involvement accompanies visceral and haematological findings only in type II and type III Gaucher patients.

p.Val452Ile mutation of the SLC25A13 gene in a Turkish patient with citrin deficiency.

Şeker-Yılmaz B, Kör D, Tümgör G, Ceylaner S, Önenli-Mungan N. p.Val452Ile mutation of the SLC25A13 gene in a Turkish patient with citrin deficiency.

Twenty-seven mutations with three novel pathologenic variants causing biotinidase deficiency: a report of 203 patients from the southeastern part of Turkey.

Background: Biotinidase deficiency (BD) is an autosomal recessive inborn error of metabolism characterized by neurologic and cutaneous symptoms and can be detected by newborn screening. Newborn screening for BD was implemented in Turkey at the end of 2008.

Methods: In total, 203 patients who were identified among the infants detected by the newborn screening were later confirmed to have BD through measurement of serum biotinidase activity.

Turkish case of ethylmalonic encephalopathy misdiagnosed as short chain acyl-CoA dehydrogenase deficiency.

Ethylmalonic encephalopathy is a very rare autosomal recessively inherited inborn error of metabolism; characterized by encephalopathy, recurrent petechiae without bleeding diathesis, chronic diarrhea, and orthostatic acrocyanosis. Here, we describe a case of ethylmalonic encephalopathy with late onset neurologic symptoms and a confusing family history of two deceased brothers with the wrong suspicion of short chain acyl-CoA dehydrogenase deficiency.

Improved metabolic control in tetrahydrobiopterin (BH4), responsive phenylketonuria with sapropterin administered in two divided doses vs. a single daily dose.

Background: Phenylketonuria (PKU) often requires a lifelong phenylalanine (Phe)-restricted diet. Introduction of 6R-tetrahydrobiopterin (BH4) has made a huge difference in the diets of patients with PKU. BH4 is the co-factor of the enzyme phenylalanine hydroxylase (PAH) and improves PAH activity and, thus, Phe tolerance in the diet.

An ignored cause of red urine in children: rhabdomyolysis due to carnitine palmitoyltransferase II (CPT-II) deficiency.

Carnitine palmitoyltransferase II (CPT-II) deficiency is an autosomal recessively inherited disorder involving the β-oxidation of long-chain fatty acids, which leads to rhabdomyolysis and subsequent acute renal failure. The clinical phenotype varies from a severe infantile form to a milder muscle form. Here, we report a 9-year-old boy referred to our hospital for the investigation of hematuria with a 2-day history of dark urine and malaise.

Impaired glucose tolerance in Fanconi-Bickel syndrome: Eight patients with two novel mutations.

Şeker-Yılmaz B, Kör D, Bulut FD, Yüksel B, Karabay-Bayazıt A, Topaloğlu AK, Ceylaner G, Önenli-Mungan N. Impaired glucose tolerance in Fanconi-Bickel syndrome: Eight patients with two novel mutations. Turk J Pediatr 2017; 59: 434-441.