Clinical Spectrum of Hereditary Spastic Paraplegia in Children : A study of 74 cases

Objectives: The aim of the study was to explore the spectrum of hereditary spastic paraplegia (HSP) in children in Oman. Methods: This retrospective study was carried out between January 1994 and August 2011 on children with delayed development, gait disorders and motor handicaps, with signs of symmetrical pyramidal tract involvement. A detailed perinatal and family history, including the age of onset of symptoms, was recorded. The children were labelled as having either the pure or complicated form of HSP based on the established diagnostic criteria. In families with more than one affected child, parents and all other siblings were also examined. Results: Within the study, 74 children from 31 families were diagnosed with HSP. Parental consanguinity was seen in 91% of cases, with 44 children (59.4%) experiencing onset of the disease under one year of age. Complicated HSP was the most common type, seen in 81.1%. Speech involvement, mental retardation, and epilepsy were the most common associated abnormalities. Nonspecific white matter changes and corpus callosum abnormalities were noted in 24.3% of cases on magnetic resonance imaging. Conclusion: The study described clinical features of 74 children with HSP. Autosomal recessive complicated HSP was seen in 81.1% of cases.

Guidelines for acute management of hyperammonemia in the Middle East region

BACKGROUND: Hyperammonemia is a life-threatening event that can occur at any age. If treated, the early symptoms in all age groups could be reversible. If untreated, hyperammonemia could be toxic and cause irreversible brain damage to the developing brain. OBJECTIVE: There are major challenges that worsen the outcome of hyperammonemic individuals in the Middle East. These include: lack of awareness among emergency department physicians about proper management of hyperammonemia, strained communication between physicians at primary, secondary, and tertiary hospitals, and shortage of the medications used in the acute management of hyperammonemia. Therefore, the urge to develop regional guidelines is extremely obvious. METHOD: We searched PubMed and Embase databases to include published materials from 2011 to 2014 that were not covered by the European guidelines, which was published in 2012. We followed the process of a Delphi conference and involved one preliminary meeting and two follow-up meetings with email exchanges between the Middle East Hyperammonemia and Urea Cycle Disorders Scientific Group regarding each draft of the manuscript. RESULTS AND DISCUSSION: We have developed consensus guidelines based on the highest available level of evidence. The aim of these guidelines is to homogenize and harmonize the treatment protocols used for patients with acute hyperammonemia, and to provide a resource to not only metabolic physicians, but also physicians who may come in contact with individuals with acute hyperammonemia. CONCLUSION: These suggested guidelines aim to ease the challenges faced by physicians dealing with acute hyperammonemia in the region. In addition, guidelines have demonstrated useful collaboration between experts in the region, and provides information that will hopefully improve the outcomes of patients with acute hyperammonemia

Guidelines for acute management of hyperammonemia in the Middle East region

BACKGROUND: Hyperammonemia is a life-threatening event that can occur at any age. If treated, the early symptoms in all age groups could be reversible. If untreated, hyperammonemia could be toxic and cause irreversible brain damage to the developing brain. OBJECTIVE: There are major challenges that worsen the outcome of hyperammonemic individuals in the Middle East. These include: lack of awareness among emergency department physicians about proper management of hyperammonemia, strained communication between physicians at primary, secondary, and tertiary hospitals, and shortage of the medications used in the acute management of hyperammonemia. Therefore, the urge to develop regional guidelines is extremely obvious. METHOD: We searched PubMed and Embase databases to include published materials from 2011 to 2014 that were not covered by the European guidelines, which was published in 2012. We followed the process of a Delphi conference and involved one preliminary meeting and two follow-up meetings with email exchanges between the Middle East Hyperammonemia and Urea Cycle Disorders Scientific Group regarding each draft of the manuscript. RESULTS AND DISCUSSION: We have developed consensus guidelines based on the highest available level of evidence. The aim of these guidelines is to homogenize and harmonize the treatment protocols used for patients with acute hyperammonemia, and to provide a resource to not only metabolic physicians, but also physicians who may come in contact with individuals with acute hyperammonemia. CONCLUSION: These suggested guidelines aim to ease the challenges faced by physicians dealing with acute hyperammonemia in the region. In addition, guidelines have demonstrated useful collaboration between experts in the region, and provides information that will hopefully improve the outcomes of patients with acute hyperammonemia

A mutation of EPT1 (SELENOI) underlies a new disorder of Kennedy pathway phospholipid biosynthesis.

Mutations in genes involved in lipid metabolism have increasingly been associated with various subtypes of hereditary spastic paraplegia, a highly heterogeneous group of neurodegenerative motor neuron disorders characterized by spastic paraparesis. Here, we report an unusual autosomal recessive neurodegenerative condition, best classified as a complicated form of hereditary spastic paraplegia, associated with mutation in the ethanolaminephosphotransferase 1 (EPT1) gene (now known as SELENOI), responsible for the final step in Kennedy pathway forming phosphatidylethanolamine from CDP-ethanolamine. Phosphatidylethanolamine is a glycerophospholipid that, together with phosphatidylcholine, constitutes more than half of the total phospholipids in eukaryotic cell membranes. We determined that the mutation defined dramatically reduces the enzymatic activity of EPT1, thereby hindering the final step in phosphatidylethanolamine synthesis. Additionally, due to central nervous system inaccessibility we undertook quantification of phosphatidylethanolamine levels and species in patient and control blood samples as an indication of liver phosphatidylethanolamine biosynthesis. Although this revealed alteration to levels of specific phosphatidylethanolamine fatty acyl species in patients, overall phosphatidylethanolamine levels were broadly unaffected indicating that in blood EPT1 inactivity may be compensated for, in part, via alternate biochemical pathways. These studies define the first human disorder arising due to defective CDP-ethanolamine biosynthesis and provide new insight into the role of Kennedy pathway components in human neurological function

Role of FANCM in Alternative Lengthening of Telomeres (ALT) Human Cells

Most immortal human cells maintain their telomeres by up-regulating the enzyme telomerase. Approximately 10-15% of immortal cells maintain their telomere lengths by a recombination-based mechanism termed alternative lengthening of telomeres (ALT). Human ALT cells are characterized by ALT associated promyelocytic bodies (APBs) that contain proteins involved in DNA damage response and repair. Our lab has found significant colocalization of several components of the Fanconi Anemia (FA) pathway with telomeres and demonstrated that knockdown of FANCD2 leads to ALT-specific increase in the amount of telomeric DNA as well as increased aneuploidy and cell death. In this study, we examined the role of FANCM in telomere maintenance in ALT cells. We found a significant colocalization of FANCM with telomeres in two ALT cell lines. Knockdown of FANCM was associated with reduced growth, increases in the size of TRF2 foci and in the amount of telomeric DNA. These data suggest that FANCM plays a role in telomere length regulation and maintenance.MAS

Syndrome of Inappropriate Antidiuretic Hormone Secretion in a Patient with Uncontrolled Tyrosinaemia Type 1

Syndrome of inappropriate antidiuretic hormone (SIADH) secretion is a recognisable complication of acute porphyria. We report a nine-year-old female patient with hereditary tyrosinaemia type 1 and poor adherence to nitisinone therapy who presented with acute abdominal pain, vomiting and lethargy at Sultan Qaboos University Hospital, Muscat, Oman in 2016. She subsequently developed generalised tonic-clonic seizures attributable to severe hyponatremia that met the diagnostic criteria of SIADH. The acute porphyria screen also appeared positive. The patient responded well to fluid restriction and was discharged home without immediate neurological sequelae. Although acute porphyria is also a recognised complication of uncontrolled tyrosinaemia type 1, to the best of the authors’ knowledge, no patient with tyrosinaemia type 1 has been reported to present with SIADH. Keywords: Tyrosinemia Type 1; Hyponatremia; Inappropriate ADH Syndrome; Case Report; Oman

Severe Acute Disseminated Encephalomyelitis Mimicking Leukodystrophy in a Child

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The landscape of acid sphingomyelinase deficiency in a new therapeutic era: insights from experts in the Gulf region

Acid sphingomyelinase deficiency (ASMD) is an autosomal-recessive progressive multiorgan metabolic disorder due to pathogenic variants in the sphingomyelin phosphodiesterase 1 gene. It can lead to death in early childhood in its most severe form. According to previous registries, the birth prevalence of ASMD is nearly 0.4-0.6 per 100,000 live births. The diagnosis of ASMD is usually delayed or missed due to the wide variability of clinical manifestations of the disease. Until recently, the management of ASMD patients was based on symptomatic treatments and supportive care; however, the introduction of enzyme replacement therapy (ERT) has revolutionized the management landscape of ASMD. ERT with a recombinant human Acid Sphingomyelinase Enzyme administered intravenously demonstrated a significant improvement in the non-neuronopathic type of ASMD in phase 2/3 trials. In June 2022, the European Medical Agency granted the ERT, olipudase alfa, marketing authorization. The prevalence of inherited metabolic disorders, including lysosomal storage diseases, is relatively higher in the Arab world than in the rest of the world due to the high consanguinity rate. In this study, we aim to review the current landscape of ASMD in the Gulf Cooperation Council countries and gather insights from experts regarding the roadmap to diagnosis, prevalence, and management approaches of ASMD in the region. [JBCGenetics 2023; 6(1.000): 41-56

Expanding the clinical spectrum of cytosolic phosphoenolpyruvate carboxykinase deficiency: novel PCK1 variants in four Arabian Gulf families

Abstract Background In metabolic stress, the cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) enzyme is involved in energy production through the gluconeogenesis pathway. PEPCK-C deficiency is a rare childhood-onset autosomal recessive metabolic disease caused by PCK1 genetic defects. Previous studies showed a broad clinical spectrum ranging from asymptomatic to recurrent hypoglycemia with/without lactic acidosis, encephalopathy, seizures, and liver failure. Results In this article, we discuss the occurrence of PEPCK-C deficiency in four families from the United Arab Emirates and Oman. All patients presented with unexplained hypoglycemia as a common feature. Two out of the seven patients presented with episodes of encephalopathy that resulted in seizures and neuroregression leading to global developmental delay and one patient had a neonatal presentation. Observed biochemical abnormalities include elevated lactate, transaminases, and tricarboxylic acid cycle metabolites in most patients. Elevated creatine kinase was documented in two patients. Whole exome sequencing revealed two novel (c.574T > C, and c.1268 C > T) and a previously reported splice site (c.961 + 1G > A) PCK1 variant in the affected families. Conclusion Patients become vulnerable during intercurrent illness; thus, prevention and prompt reversal of a catabolic state are crucial to avoid irreversible brain damage. This report will help to expand the clinical understanding of this rare disease and recommends screening for PEPCK-C deficiency in unexplained hypoglycemia