Publications by authors named "Mohamed Abdel-Hamid"

Introduction: Pontocerebellar hypoplasia (PCH) represents a group of rare disorders with prenatal onset and time-dependent loss of brain parenchyma, predominantly affecting the cerebellum and pons with variable involvement of supratentorial structures. Radiologically and pathologically, they are characterized by small cerebellum and pons. Our study aimed to screen for the gene variants in Egyptian patients with PCH for proper counseling and to describe the brain MRI and the clinical phenotype and compare, them to those described in the literature.

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  • Recent findings show biallelic loss of function variants in the ESAM gene linked to prenatal intracranial hemorrhage in 14 individuals across 9 families, including 4 patients from two families with varied clinical presentations.
  • Brain imaging revealed different neurological issues such as encephalopathy, seizures, and hydrocephalus, with one patient showing unique symptoms like white matter volume loss and porencephalic cysts.
  • Exome sequencing uncovered two new harmful ESAM variants and an additional MC4R variant in one patient, suggesting a connection to obesity and highlighting ESAM's role as a critical gene affecting brain health.
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  • 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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Objective: GAPO syndrome is usually diagnosed clinically owing to its characteristic features of growth retardation, alopecia, pseudoanodontia, and ophthalmic anomalies. Pseudoanodontia describes the failure of eruption of the two sets of teeth in these patients. Thus, the abnormal dental phenotype is the emergence of a set or part of a set of dentitions.

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Primary mitochondrial diseases (PMDs) are among the most common inherited neurological disorders. They are caused by pathogenic variants in mitochondrial or nuclear DNA that disrupt mitochondrial structure and/or function, leading to impaired oxidative phosphorylation (OXPHOS). One emerging subcategory of PMDs involves defective phospholipid (PL) metabolism.

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Purpose: This study aims to comprehensively delineate the phenotypic spectrum of ACTL6B-related disorders, previously associated with both autosomal recessive and autosomal dominant neurodevelopmental disorders. Molecularly, the role of the nucleolar protein ACTL6B in contributing to the disease has remained unclear.

Methods: We identified 105 affected individuals, including 39 previously reported cases, and systematically analysed detailed clinical and genetic data for all individuals.

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Patatin-like phospholipase domain-containing lipase 8 (PNPLA8), one of the calcium-independent phospholipase A2 enzymes, is involved in various physiological processes through the maintenance of membrane phospholipids. Biallelic variants in PNPLA8 have been associated with a range of paediatric neurodegenerative disorders. However, the phenotypic spectrum, genotype-phenotype correlations and the underlying mechanisms are poorly understood.

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Objectives: Acatalasemia is a very rare disorder characterized by gangrenous oral ulcerations and is caused by biallelic variants in the CAT gene which encodes the catalase enzyme that decomposes the hydrogen peroxide molecules to remove their toxic effect. We report two siblings from a consanguineous Egyptian family presenting with joint hyperlaxity, loose dentitions with gangrenous periodontitis, and early loss of teeth.

Study Design: The patients were clinically suspected to have the periodontal type of Ehlers-Danlos syndrome and thus genetic testing of C1S and C1R causative genes was carried out first by Sanger sequencing then exome sequencing (ES) was considered.

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Background: Trauma is a significant cause of mortality, especially among individuals aged between 15 and 44 years, with a substantial burden falling on economically active populations. Low- and middle-income countries (LMICs) bear the burden of trauma-related deaths, accounting for over 90 % globally. In Egypt, trauma rates are increasing, primarily due to road traffic crashes (RTC), affecting males disproportionately.

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Objective: Dentinogenesis imperfecta (DI) is an inherited dentin defect and may be isolated or associated with disorders such as osteogenesis imperfecta, odontochondrodysplasia Ehler-Danlos and others. Isolated DI is caused mainly by pathogenic variants in DSPP gene and around 50 different variants have been described in this gene. Herein, we report on 19 patients from two unrelated Egyptian families with isolated DI.

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Biallelic pathogenic variants in MADD lead to a very rare neurodevelopmental disorder which is phenotypically pleiotropic grossly ranging from severe neonatal hypotonia, failure to thrive, multiple organ dysfunction, and early lethality to a similar but milder phenotype with better survival. Here, we report 5 patients from 3 unrelated Egyptian families in whom 4 patients showed the severe end of the spectrum displaying neonatal respiratory distress, hypotonia and chronic diarrhea while one patient presented with the mild form displaying moderate intellectual disability and myopathy. In addition, we observed distal arthrogryposis and nonspecific structural brain anomalies in all our patients.

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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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  • The study focuses on a protein called SPOUT1/CENP-32, which is crucial for proper chromosome alignment during cell division.
  • When this protein is depleted, it causes problems like centrosome detachment and chromosome misalignment, leading to significant developmental issues.
  • The research also links genetic variants in humans to neurodevelopmental delays and identifies a disorder called SpADMiSS, characterized by symptoms like developmental delays, microcephaly, seizures, and short stature due to defects in cell division.
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Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of epilepsies characterized by early-onset, refractory seizures associated with developmental regression or impairment, with a heterogeneous genetic landscape including genes implicated in various pathways and mechanisms. We retrospectively studied the clinical and genetic data of patients with genetic DEE who presented at two tertiary centers in Egypt over a 10-year period. Exome sequencing was used for genetic testing.

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Loss-of-function mutation of ABCC9, the gene encoding the SUR2 subunit of ATP sensitive-potassium (KATP) channels, was recently associated with autosomal recessive ABCC9-related intellectual disability and myopathy syndrome (AIMS). Here we identify nine additional subjects, from seven unrelated families, harbouring different homozygous loss-of-function variants in ABCC9 and presenting with a conserved range of clinical features. All variants are predicted to result in severe truncations or in-frame deletions within SUR2, leading to the generation of non-functional SUR2-dependent KATP channels.

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The homologous genes GTPBP1 and GTPBP2 encode GTP-binding proteins 1 and 2, which are involved in ribosomal homeostasis. Pathogenic variants in GTPBP2 were recently shown to be an ultra-rare cause of neurodegenerative or neurodevelopmental disorders (NDDs). Until now, no human phenotype has been linked to GTPBP1.

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Objectives: describing the clinical features of twelve Egyptian patients with Papillon-Lefever syndrome (PLS). Five novel mutations in the cathepsin C (CTSC) gene are introduced and the phenotype of the syndrome is expanded by the identification of new clinical features.

Design: the clinical, oro-dental data of twelve Egyptian patients from seven unrelated families are described.

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An innovative, simple, accurate, sensitive, and eco-friendly synchronous fluorescence spectrofluorimetric method has been developed for the simultaneous analysis of montelukast sodium (MON) and fexofenadine hydrochloride (FEX). The method relies on measuring the relative synchronous fluorescence intensity of both drugs using Δλ of 60 nm in methanol at 405 nm for MON and 288 nm for FEX. The experimental parameters influencing the developed method were investigated and optimized.

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Recently, significant attention has been directed towards digital image colorimetry DIC using mobile applications or available software programs, which offer the advantage of analyzing samples without the need for sophisticated instruments. One such image processing program is Image J, widely used for obtaining quantitative information from scientific images. Image J could measure the color intensities by quantifying of the RGB (red-green-blue) gray levels across the images of colored substances.

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Introduction: We report on a 4-year-old female patient who presented with severe intellectual disability, autistic features, hyperlaxity of joints, and progressive scoliosis. Whole-exome sequencing identified a de novo missense variant (c.976C>T; p.

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Pontocerebellar hypoplasia (PCH) is a rare heterogeneous neurodegenerative disorder affecting the pons and cerebellum and is currently classified into 17 types (PCH1-PCH17). PCH1 is distinguishable from other types by the association of spinal motor neuron dysfunction. Based on the underlying genetic etiology, PCH1 is further classified into 6 different subtypes (PCH1 A-F).

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Progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) and PEHO-like syndromes are very rare infantile disorders characterized by profound intellectual disability, hypotonia, convulsions, optic, and progressive brain atrophy. Many causative genes for PEHO and PEHO-like syndromes have been identified including CCDC88A. So far, only five patients from two unrelated families with biallelic CCDC88A variants have been reported in the literature.

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Article Synopsis
  • * A specific genetic mutation (R253*) was found in two siblings experiencing severe neurological and tumor-related health issues, which was associated with significant cellular abnormalities and inefficient protein function.
  • * Another mutation (R227*) identified in a different patient is likely tied to complete loss of p31comet function, further indicating that mutations in this gene are linked to risks for aneuploidy and cancer development.
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