Diagnostic yield of exome sequencing-based copy number variation analysis in Mendelian disorders: a clinical application.

Next-generation sequencing (NGS) coupled with bioinformatic tools has revolutionized the detection of copy number variations (CNVs), which are implicated in the emergence of Mendelian disorders. In this study, we evaluated the diagnostic yield of exome sequencing-based CNV analysis in 449 patients with suspected Mendelian disorders. We aimed to assess the diagnostic yield of this recently utilized method and expand the clinical spectrum of intragenic CNVs.

Glutaric aciduria and L-2-hydroxyglutaric aciduria: Clinical and molecular findings of 35 patients from Turkey.

Background: Cerebral organic acid disorders are progressive neurometabolic diseases characterized by neurologic dysfunction. Glutaric aciduria type I (GA-I) and L-2-hydroxyglutaric aciduria (L2HGA) are the main cerebral organic acid disorders. They are both classified as, and it is suggested that these two disorders may share a common metabolic pathway.

N-acetylcysteine and cysteamine bitartrate prevent azide-induced neuromuscular decompensation by restoring glutathione balance in two novel surf1-/- zebrafish deletion models of Leigh syndrome.

SURF1 deficiency (OMIM # 220110) causes Leigh syndrome (LS, OMIM # 256000), a mitochondrial disorder typified by stress-induced metabolic strokes, neurodevelopmental regression and progressive multisystem dysfunction. Here, we describe two novel surf1-/- zebrafish knockout models generated by CRISPR/Cas9 technology. While gross larval morphology, fertility, and survival into adulthood appeared unaffected, surf1-/- mutants manifested adult-onset ocular anomalies and decreased swimming activity, as well as classical biochemical hallmarks of human SURF1 disease, including reduced complex IV expression and enzymatic activity and increased tissue lactate.

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.

A rare case of hypomyelinating leukodystrophy-14 benefiting from ketogenic diet therapy.

Background: Hypomyelinating leukodystrophy-14 (HLD14) is a rarely seen neurodevelopmental disease caused by homozygous pathogenic ubiquitin-fold modifier 1 gene variants. The disease has an autosomal recessive inheritance. All patients with this condition reported to date have drug-resistant epilepsy.

A female case of 5,10-methenyltetrahydrofolate synthetase deficiency with novel neuro-imaging abnormalities.

Background: Folate metabolism disorders can affect various organ systems, including the nervous system. 5,10-methenyltetrahydrofolate synthetase deficiency is a rare cerebral folate deficiency in which MTHFS activity is disrupted with low-normal cerebrospinal fluid (CSF) 5,10-methenyltetrahydrofolate levels, while peripheral folate levels are normal.

Case Report: We present here a female patient with developmental delay, microcephaly, hypotonia, nystagmus, and seizure in which a distinct brain MRI and CT showed restricted diffusion in the bilateral parietal and occipital lobes, and calcifications of the bilateral putamen, globus pallidus, and caudate nucleus, and the bilateral parietal and occipital lobes.

The effectiveness of the ketogenic diet in drug-resistant childhood epilepsy.

Background: We aimed to investigate the effectiveness of ketogenic diet (KD) in children with various types of refractory epilepsy.

Methods: A total of 91 children (49 females) aged 3 to 193 months (median, 52 months) with drug resistant epilepsy who received KD treatment for at least 12 months were enrolled in the study. Seizure frequency, adherence to diet, reason for discontinuation of KD, and adverse effects were recorded.

Biallelic ZNFX1 variants are associated with a spectrum of immuno-hematological abnormalities.

Biallelic changes in the ZNFX1 gene have been recently reported to cause severe familial immunodeficiency. Through a search of our bio/databank with information from genetic testing of >55 000 individuals, we identified nine additional patients from seven families with six novel homozygous ZNFX1 variants. Consistent with the previously described phenotype, our patients suffered from monocytosis, thrombocytopenia, hepatosplenomegaly, recurrent infections, and lymphadenopathy.

The effect of ketogenic diet on serum lipid concentrations in children with medication resistant epilepsy.

Background: Ketogenic diet (KD) is a valuable treatment option for patients with medication-resistant epilepsy. It is associated with a number of side effects. However limited data are available for the long-term effects of KD on serum lipid levels.

The utility of reverse phenotyping: a case of lysinuric protein intolerance presented with childhood osteoporosis.

Objectives: Childhood osteoporosis is often a consequence of a chronic disease or its treatment. Lysinuric protein intolerance (LPI), a rare secondary cause of the osteoporosis, is an autosomal recessive disorder with clinical features ranging from minimal protein intolerance to severe multisystemic involvement. We report a case diagnosed to have LPI using a Next Generation Sequencing (NGS) panel and evaluate the utility of reverse phenotyping.

The utility of next-generation sequencing technologies in diagnosis of Mendelian mitochondrial diseases and reflections on clinical spectrum.

Objectives: Diagnostic process of mitochondrial disorders (MD) is challenging because of the clinical variability and genetic heterogeneity of these conditions. Next-Generation Sequencing (NGS) technology offers a high-throughput platform for nuclear MD.

Methods: We included 59 of 72 patients that undergone WES and targeted exome sequencing panel suspected to have potential PMDs.

Inborn errors of metabolism in palliative care.

Background: In parallel with the increase in the number of children with life-limiting or life-threatening diseases, the need for and right to pediatric palliative care is also increasing. This study aimed to examine the metabolic diseases, evaluate the symptoms, and review the needs of children who were admitted to the pediatric palliative care service.

Methods: Following the approval of the local ethics committee (18/7/2019-107), the computer records of patients hospitalized in the pediatric palliative care service between December 1, 2018 and January 6, 2019 were reviewed retrospectively.

Neuronal ceroid lipofuscinosis: genetic and phenotypic spectrum of 14 patients from Turkey.

Introduction And Purpose: Neuronal ceroid lipofuscinoses (NCLs) is a group of congenital metabolic diseases where the neurodegenerative process with the accumulation of ceroid and lipofuscin autofluorescent storage materials is at the forefront. According to the age of presentation, NCLs are classified as congenital, infantile (INCL), late infantile (LINCL), juvenile (JNCL), and adult (ANCL) NCLs. In our study, it was aimed to discuss the clinical and molecular characteristics of our patients diagnosed with NCL.

Expanding the spectrum of VAC14 related pediatric-onset neurological disease; striatonigral degeneration with brainstem involvement.

VAC14 related childhood-onset striatonigral degeneration was first defined in 2016 in two unrelated children with sudden onset neurological disease and regression of developmental milestones. Up to now, 11 cases have been reported. VAC14 is a component of a trimolecular complex that tightly regulates the level of phosphatidylinositol 3,5-bisphosphate (PI (3, 5)P2) and PI (3, 5)P2 is critical for the survival of neural cells.

related Leigh syndrome: Clinical and molecular findings of 16 patients from Turkey.

Introduction: Pathogenic variants in , a nuclear-encoded gene encoding a mitochondrial chaperone involved in COX assembly, are one of the most common causes of Leigh syndrome (LS).

Material-methods: Sixteen patients diagnosed to have -related LS between 2012 and 2020 were included in the study. Their clinical, biochemical and molecular findings were recorded.

Cascade screening and treatment of children with familial hypercholesterolemia in Turkey.

Objectives Premature coronary artery disease is the most common preventable cause of death in developed countries, and familial hypercholesterolemia (FH) is the most common monogenetic disorder of lipid metabolism, predisposing for premature coronary artery. FH is the most common preventable cause of death in developed countries. In 2016, the national lipid screening program in school-age children has been started in Turkey.

Different clinical presentation in a patient with two novel pathogenic variants of the FBXL4 gene.

Background: The recently described FBXL4-related encephalomyopathic mitochondrial DNA depletion syndrome 13 (MTDPS13) manifests with severe encephalopathy, early-onset lactic acidosis, hypotonia, developmental delay and feeding difficulty. Less than 100 cases with FBXL4-related MTDPS13 and 47 pathogenic mutations in the FBXL4 gene have been identified thus far. Here, we describe a patient diagnosed with MTDPS13 with two novel variants of the FBXL4 gene.

A neglected cause of recurrent rhabdomyolysis, LPIN1 gene defect: a rare case from Turkey.

Background: Rhabdomyolysis; can occur due to toxic, infectious, metabolic, and genetic causes. Severe rhabdomyolysis may progress to several clinical manifestations such as cardiac arrest and may pose a risk of mortality if it is not treated timely.

Case: In this article, we presented a 26-month-old patient who was admitted with an acute rhabdomyolysis attack and a venovenous hemodiafiltration (CVVHDF) was initiated on the 5th hour of hospitalization.

A new mutation associated with Pierson syndrome.

Pierson syndrome is characterized by congenital nephrotic syndrome and bilateral microcoria. Genetically, mutations in the LAMB2 gene, which encodes the laminin β2 chain, lead to this disorder. To date, 98 cases and 50 different mutations have been reported in literature.

Clinical findings in five Turkish patients with citrin deficiency and identification of a novel mutation on SLC25A13.

Background Citrin deficiency (CD) is an autosomal recessive genetic disorder caused by a defect in the mitochondrial aspartate/glutamate antiporter, citrin. Three clinical manifestations have been described until today. Case presentation We reported 5 CD patients from two families.