Publications by authors named "Sedat Isikay"

Article Synopsis
  • FLVCR1 is a protein involved in transporting essential compounds like heme and choline, with mutations linked to serious developmental disorders and neurodegenerative conditions in humans.
  • Researchers identified 30 patients with biallelic FLVCR1 variants who displayed severe developmental issues, including brain malformations and other complications, paralleling symptoms seen in mouse models and conditions like Diamond-Blackfan anemia (DBA).
  • The findings emphasize that FLVCR1 variants could cause a wide range of health problems, underscoring the need for diverse genetic testing and consideration of animal model data in understanding human genetic disorders.
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Primary proteasomopathies have recently emerged as a new class of rare early-onset neurodevelopmental disorders (NDDs) caused by pathogenic variants in the PSMB1, PSMC1, PSMC3, or PSMD12 proteasome genes. Proteasomes are large multi-subunit protein complexes that maintain cellular protein homeostasis by clearing ubiquitin-tagged damaged, misfolded, or unnecessary proteins. In this study, we have identified PSMD11 as an additional proteasome gene in which pathogenic variation is associated with an NDD-causing proteasomopathy.

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encodes Feline leukemia virus subgroup C receptor 1 (FLVCR1), a solute carrier (SLC) transporter within the Major Facilitator Superfamily. FLVCR1 is a widely expressed transmembrane protein with plasma membrane and mitochondrial isoforms implicated in heme, choline, and ethanolamine transport. While knockout mice die with skeletal malformations and defective erythropoiesis reminiscent of Diamond-Blackfan anemia, rare biallelic pathogenic variants are linked to childhood or adult-onset neurodegeneration of the retina, spinal cord, and peripheral nervous system.

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Article Synopsis
  • Hair microscopy is a quick diagnostic tool that can help identify various diseases affecting hair, especially in pediatric neurology patients with hair shaft disorders.* -
  • The study analyzed 16 children with unique hair issues, revealing conditions like giant axonal neuropathy and Griscelli syndrome through specific hair characteristics identified during microscopic evaluation.* -
  • The findings suggest that incorporating hair examinations into physical and neurological assessments can lead to earlier detection of rare diseases related to abnormal hair conditions.*
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Myokymia is a rare neuromuscular disorder and limb involvement is not common in this disease. To the best of our knowledge, isolated peroneus longus muscle myokymia was not reported before in the literature; and for that reason treatment protocols were not established. Botulinum toxin type A (BoNT-A), which is used in the treatment of a variety of neurologic disorders, was also defined as a treatment option in myokymia.

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Genetic heterogeneity, reduced penetrance, and variable expressivity, the latter including asymmetric body axis plane presentations, have all been described in families with congenital limb malformations (CLMs). Interfamilial and intrafamilial heterogeneity highlight the complexity of the underlying genetic pathogenesis of these developmental anomalies. Family-based genomics by exome sequencing (ES) and rare variant analyses combined with whole-genome array-based comparative genomic hybridization were implemented to investigate 18 families with limb birth defects.

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Neurodevelopmental disorder with microcephaly, ataxia, and seizures (NEDMAS) syndrome is a rare neurodevelopmental disorder characterized by moderate intellectual disability (ID), thin body habitus, microcephaly, seizures, ataxia, muscle weakness, and speech impairment. So far, only two families with NEDMAS have been reported. We report the clinical and molecular characteristics of three unrelated Turkish families with four NEDMAS patients.

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Unlabelled: Pineal glioblastomas (GBMs) are extremely rare tumors. Herein we will present a pediatric patient with GBM located in pineal region who was admitted with the symptoms of increased intracranial pressure and treated with surgical resection and radiotherapy.

Introduction: Pineal region tumors are extremely rare accounting for less than 1% of all brain tumors.

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Article Synopsis
  • - Neurodevelopmental disorders (NDDs) affect over 3% of the population, posing significant social and economic challenges; despite advances in genomics, many cases remain undiagnosed.
  • - A study of 234 new subjects and 20 previously unsolved Turkish families used genome-wide screening, identifying clear genetic causes in 75.2% of families, with 218 distinct genes linked to these disorders.
  • - Notably, 28.9% of solved families exhibited multilocus pathogenic variations, often due to identical-by-descent segments in their genomes; additional sequencing helped achieve diagnoses in 25% of previously undiagnosed families.
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Background: Disturbance of sleep habits leads to excessive daytime sleepiness (EDS), which may affect learning abilities and consequently academic performance. Therefore the main purpose of current paper was to determine the prevalence of headache and Restless legs syndrome (RLS) in school-aged adolescents and to evaluate the type of headache in adolescents, with a secondary aim to determine the effect of daytime sleepiness on academic success.

Methods: This cross-sectional study was conducted on adolescents aged between 15 and 19 years of age, who were in high school education in the 2016-2017 academic years in Kahramanmaraş province.

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Article Synopsis
  • - The study explores the previously unknown function of the C2orf69 gene, linking it to a severe syndrome in 20 children characterized by fatal autoinflammation and progressive brain issues.
  • - Genetic analysis revealed homozygous loss-of-function variants in C2orf69, suggesting its key role in brain and immune system development through its influence on mitochondrial function and GBE1 levels.
  • - Experimentation on zebrafish demonstrated that inactivation of C2orf69 leads to early death due to epilepsy and brain inflammation, further supporting its crucial role in neural and immune health.
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Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy. In this report, we present a 3-year-old girl diagnosed with cortical and subcortical hemorrhage during the course of GBS who was treated with intravenous immunoglobulin. To the best of our knowledge, central nervous system hemorrhage during the course of GBS is an extremely rare condition.

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Objective: Defects in ion channels and neurotransmitter receptors are implicated in developmental and epileptic encephalopathy (DEE). Metabotropic glutamate receptor 7 (mGluR7), encoded by GRM7, is a presynaptic G-protein-coupled glutamate receptor critical for synaptic transmission. We previously proposed GRM7 as a candidate disease gene in two families with neurodevelopmental disorders (NDDs).

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The apical Par complex, which contains atypical protein kinase C (aPKC), Bazooka (Par-3), and Par-6, is required for establishing polarity during asymmetric division of neuroblasts in Drosophila, and its activity depends on L(2)gl. We show that loss of Ankle2, a protein associated with microcephaly in humans and known to interact with Zika protein NS4A, reduces brain volume in flies and impacts the function of the Par complex. Reducing Ankle2 levels disrupts endoplasmic reticulum (ER) and nuclear envelope morphology, releasing the kinase Ballchen-VRK1 into the cytosol.

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Arthrogryposis is a clinical finding that is present either as a feature of a neuromuscular condition or as part of a systemic disease in over 400 Mendelian conditions. The underlying molecular etiology remains largely unknown because of genetic and phenotypic heterogeneity. We applied exome sequencing (ES) in a cohort of 89 families with the clinical sign of arthrogryposis.

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Muscular dystrophy-dystroglycanopathy is a heterogeneous group of inherited muscular dystrophies caused by glycosylation defects associated with different mutations. The main finding of the disease is disruption of the binding of cellular α-dystroglycan to its extracellular matrix ligands. O-mannose β-1,2-N-acetylglucosaminyltransferase 1 is one of the pathogenic genes involved in glycosylation defects of α-dystroglycan.

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Aminoacyl tRNA synthetases (ARSs) link specific amino acids with their cognate transfer RNAs in a critical early step of protein translation. Mutations in ARSs have emerged as a cause of recessive, often complex neurological disease traits. Here we report an allelic series consisting of seven novel and two previously reported biallelic variants in valyl-tRNA synthetase (VARS) in ten patients with a developmental encephalopathy with microcephaly, often associated with early-onset epilepsy.

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Ca signaling is vital for various cellular processes including synaptic vesicle exocytosis, muscle contraction, regulation of secretion, gene transcription, and cellular proliferation. The endoplasmic reticulum (ER) is the largest intracellular Ca store, and dysregulation of ER Ca signaling and homeostasis contributes to the pathogenesis of various complex disorders and Mendelian disease traits. We describe four unrelated individuals with a complex multisystem disorder characterized by woolly hair, liver dysfunction, pruritus, dysmorphic features, hypotonia, and global developmental delay.

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Background: Febrile seizure is the most common childhood neurological disorder, is an important health problem with potential short- and long-term complications, also leading to economic burden and increased parental anxiety about fevers and seizures occurring in their children. There are no routine recommendation to detect etiological causes of FS for neurological perspective, further knowledge about the etiological causes of FS in children will support preventive measures and follow-up strategies. The aim of this study is to evaluate the percentage of respiratory viruses in children with FS.

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