Review of the spectrum of tuberous sclerosis complex: The Saudi Arabian Experience.

OBJECTIVES: To determine the prevalence of tuberous sclerosis complex (TSC) in the paediatric Saudi population and to characterise the range of clinical symptoms, neurocutaneous findings, neuroimaging results, and complications of the disease. METHODS: A total of 61 genetically confirmed TSC patients from the National Guard Health Affairs (NGHA) in Saudi Arabia were the subject of this retrospective descriptive analysis. The data were presented using descriptive measures. RESULTS: The mean age at diagnosis was found to be 4.9 years. Subependymal nodules (86.9%), numerous cortical tubers and/or radial migration lines (63.9%), and hypomelanotic macules (63.9%) were the 3 most common significant criteria. The vast majority (86.9%) of those diagnosed had epilepsy, of which 50% were considered medically intractable. Nearly half of our subjects underwent genetic testing, which revealed that TSC2 predominated over TSC1. Symptoms of Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders (TAND) were present in 66.7% of TSC1 patients and 73.9% of TSC2 patients. CONCLUSION: The findings of this study demonstrate that the clinical spectrum of TSC among Saudi children is consistent with the body of existing literature. The TSC2 was more prevalent than TSC1. The most frequent signs were cutaneous and neurological. Monitoring TSC patients regularly is crucial to identify any issues as soon as possible.

Epidemiology and Outcomes of Neurofibromatosis Type 1 (NF-1): Multicenter Tertiary Experience.

Purpose: The aim of this manuscript was to assess the epidemiology and clinical features of Neurofibromatosis type 1 (NF-1) based on the newly published revised NF-1 diagnostic criteria and to evaluate complications of NF-1 including neurodevelopmental disorders. Patients and methods: A retrospective cross-sectional observational study was conducted in the Ministry of National Guard Health Affairs (MNGHA) healthcare organization branches including four tertiary hospitals and 51 primary health care centers in different regions in Saudi Arabia. This study included all patients diagnosed with NF1 using the revised NIH diagnostic criteria published in 2021 that were registered at the electronic medical records (EMR) from 2015 to 2021. Results: A total of 184 patients fulfilled the diagnostic criteria and were included in this study. The median age at diagnosis was 11 years (IQR: 4.00-20.25). The most encountered diagnostic criteria in this study were Café-au-lait macules (85.3%), and (42.9%) were found to have two or more neurofibromas with plexiform neurofibroma being the most common subtype (23.36%), approximately (36.4%) of the patient with optic pathway glioma. Nearby (26.6%) of the patients displayed different type of tumors. Iris Lisch nodules were presented in 36.4% of patients at a median age of 12 years (IQR: 9.0-21.8). Cardiovascular abnormality was encountered in 9.8% of the patients. Around 27.7% of the patients reported headache and 11.4% of the patient suffered from different type of epilepsy. Besides, 10.5% of the patients had intellectual disability, 33.8% suffered from communication disorders, and 4.9% patients had ADHD. Conclusion: The results of this study will enable practitioners to adopt a more holistic approach and prioritize numerous attributes, which they can subsequently incorporate into their therapeutic methodologies. Furthermore, the identification of these attributes will facilitate an expeditious and accurate diagnosis. Hence, the implementation of intervention during its nascent phase may result in a more advantageous consequence.

Further delineation of Wiedemann-Rautenstrauch syndrome linked with POLR3A.

Wiedemann-Rautenstrauch Syndrome (WRS; MIM 264090) is an extremely rare and highly heterogeneous syndrome that is inherited in a recessive fashion. The patients have hallmark features such as prenatal and postnatal growth retardation, short stature, a progeroid appearance, hypotonia, facial dysmorphology, hypomyelination leukodystrophy, and mental impairment. Biallelic disease-causing variants in the RNA polymerase III subunit A (POLR3A) have been associated with WRS. Here, we report the first identified cases of WRS syndrome with novel phenotypes in three consanguineous families (two Omani and one Saudi) characterized by biallelic variants in POLR3A. Using whole-exome sequencing, we identified one novel homozygous missense variant (NM_007055: c.2456C>T; p. Pro819Leu) in two Omani families and one novel homozygous variant (c.1895G>T; p Cys632Phe) in Saudi family that segregates with the disease in the POLR3A gene. In silico homology modeling of wild-type and mutated proteins revealed a substantial change in the structure and stability of both proteins, demonstrating a possible effect on function. By identifying the homozygous variants in the exon 14 and 18 of the POLR3A gene, our findings will contribute to a better understanding of the phenotype-genotype relationship and molecular etiology of WRS syndrome.

Case report: A founder UGDH variant associated with developmental epileptic encephalopathy in Saudi Arabia.

Congenital disorders of glycosylation (CDG) are a group of more than 100 rare genetic disorders characterized by impaired glycosylation of proteins and lipids. The clinical presentation of CDG varies tremendously, from single-organ to multi-organ involvement and from prenatal death to a normal adult phenotype. In this case study, we report a large consanguineous family with multiple children suffering from cerebral palsy, seizure, developmental and epileptic encephalopathy, and global developmental delay. Whole-exome sequencing (WES) analysis revealed a homozygous variant in the UDP-glucose dehydrogenase (UGDH) gene (c.950G>A; p.R317Q) which segregates with the familial phenotype with a plausible autosomal recessive mode of inheritance, indicating a potential disease-causing association. The UGDH gene encodes the UDP-glucose dehydrogenase, a key enzyme in the synthesis of specific extracellular matrix constituents (proteoglycans and glycolipids) involved in neural migration and connectivity during early brain development. Many pathogenic mutations of UGDH have been reported in recent literature works. However, the variant identified in this study has been observed only in the Saudi population (13 families) and not in any other ethnic background, suggesting that it may be an ancient founder mutation.

A rare cerebellar vermis high-grade neuroepithelial tumor: Radiological-pathological correlation.

Neuroepithelial tumors, formerly known as primitive neuroectodermal tumors of the central nervous system, are reclassified under embryonal tumors in the 2016 WHO Classification of Tumors of the Central Nervous System. The tumor has two known genetic alterations: HGNET-MN1 and HGNET-BCOR. Previously, radiological features of the tumor have been reported as large, intra-axial lesions in the cerebral or cerebellar hemisphere, which presents mild adjacent edema. Here, we report the first case of high-grade neuroepithelial tumor not elsewhere classified (HGNET-NEC) arising from the cerebellar vermis, demonstrating good outcomes in clinical follow-up when compared with previously known types.

WNT-activated Pediatric Medulloblastoma Associated With Metastasis to the Suprasellar Region and Hypopituitarism.

We report on a rare association of WNT-activated medulloblastoma with metastasis to the suprasellar region. Medulloblastoma is the commonest brain tumor in children, and the most common pattern of metastatic disease is that of leptomeningeal involvement and spinal metastasis. Historically, medulloblastoma patients were categorized into different risk groups on the basis of age, histology, size of residium after surgery, and metastatic status, but the discovery of at least 4 molecular subgroups has changed the way these tumors are now treated. We report a 6-year-old patient who had a rare association of WNT-activated medulloblastoma with suprasellar metastasis and went on to develop hypopituitarism during the course of treatment. He remains alive 1 year after completing treatment.

Segmental spinal dysgenesis with open spinal dysraphism and Chiari II features, case report.

Segmental spinal dysgenesis (SSD) is a complex spinal anomaly characterized by localized dysgenesis of the lumbar or thoracolumbar spine, and severe congenital kyphosis or kyphoscoliosis. We describe a newborn who presented with severe congenital paraplegia and a lumbar mass. Magnetic resonance imaging confirmed SSD type II associated with open spinal dysraphism and intracranial Chiari II features; this association has not been reported. The association modifies the disease management and outcome. The previous classification of SSD could be revisited based on our case.

PDCD6IP, encoding a regulator of the ESCRT complex, is mutated in microcephaly.

Primary microcephaly (PM) is a highly heterogeneous neurodevelopmental disorder with many contributing risk genes and loci identified to date. We report a consanguineous family with PM, intellectual disability and short stature. Using whole exome sequencing, we identified a homozygous frameshift variant in programmed cell death 6 interacting protein (PDCD6IP, c.154_158dup; p.Val54Profs*18). This gene, PDCD6IP, plays an important role in the endosomal sorting complexes required for transport (ESCRT) pathway in the abscission stage of cytokinesis and apoptosis, and is required for normal brain development in mice. The clinical features observed in our patient were similar to the phenotypes observed in mouse and zebrafish models of PDCD6IP mutations in previous studies. This study provides evidence that clinical manifestations of PDCD6IP mutations as seen in our patients with PM and ID may be a novel cause for neurodevelopmental disorders.

Multiple Sulfatase Deficiency: A Case Series With a Novel Mutation.

Multiple sulfatase deficiency is an autosomal recessive lysosomal storage disorder due to a deficiency in formylglycine-generating enzyme, which is encoded by the Sulfatase Modifying Factor 1 ( SUMF1) gene. Clinically, the disorder is variable. The most common characteristics are developmental regression, intellectual disability, ichthyosis, and periventricular white matter disease. Herein, we report 6 Saudi patients with multiple sulfatase deficiency caused by a novel homozygous missense mutation in the SUMF1 gene (NM_182760.3; c.785A>G [p.Gln262Arg]). The patients are 2 females and 4 males between 5 and 13 years of age, with an age of onset of 1 to 3 years. All patients are consanguineous and suffer from developmental regression, intellectual disability, ichthyosis, and periventricular white matter disease. This cohort differs from previous cohorts because of the absence of organomegaly and skeletal abnormalities.

A mendelian form of neural tube defect caused by a de novo null variant in SMARCC1 in an identical twin.

Neural tube defects (NTDs) are among the most common birth defects in humans and yet their molecular etiology remains poorly understood. NTDs are believed to result from the complex interaction of environmental factors with a multitude of genetic risk factors in a classical multifactorial disease model. Mendelian forms of NTDs in which single variants are sufficient to cause the disease are extremely rare. We report a monozygotic twin with severe NTDs (occipital encephalocele and myelomeningocele) and a shared de novo, likely truncating, variant in SMARCC1. RTPCR analysis suggests the potential null nature of the variant attributed to nonsense-mediated decay. SMARCC1 is extremely constrained in humans and encodes a highly conserved core chromatin remodeler, BAF155. Mice that are heterozygous for a null allele or homozygous for a hypomorphic allele develop severe NTDs in the form of exencephaly. This is the first report of SMARCC1 mutation in humans, and it shows a critical and conserved requirement for intact BAF chromatin remodeling complex in neurulation. Ann Neurol 2018;83:433-436.

Severe Crohn's Disease Manifestations in a Child with Cystathionine ß-Synthase Deficiency.

Inflammatory bowel diseases (IBDs) are idiopathic autoimmune diseases that are characterized by inflammation of both the small and large intestine. Although IBD is common in the general population, the pathophysiology remains ambiguous. Clear understanding of IBD pathophysiology would be a major step toward curative treatment in the future. Hyperhomocysteinemia has been associated with multiple autoimmune diseases including IBD, but homocystinuria has not been associated with IBD before. We report a 9-year-old girl with Crohn's disease and homocystinuria. Her gastrointestinal symptoms improved significantly upon classical homocystinuria treatment, and her last colonoscopy showed a pronounced remission. This case supports the inflammatory role of homocysteine in the gastrointestinal tract and the association between hyperhomocysteinemia and IBD manifestations.

Renal lymphangiomatosis, a rare differential diagnosis for autosomal recessive polycystic kidney disease in pediatric patients.

Renal lymphangiomatosis is a rare, benign malformation, characterized by developmental malformation of the perirenal, peripelvic, and intrarenal lymphatics. Radiologist knowledge of the unique radiological features of this entity helps patient's safety in terms of management. We study the case of a 27-month-old boy presented to the emergency department with upper respiratory tract infection. He had a high blood pressure and had been diagnosed earlier with autosomal recessive polycystic kidney disease based on renal ultrasound findings. Because the clinical presentation and laboratory work of the patient did not support the diagnosis of autosomal recessive polycystic kidney disease, further, extensive work-up was performed, which confirmed the diagnosis of renal lymphangiomatosis. This case report emphasizes the imaging features of this rare entity to promote early diagnosis and better patient care.

Extraneural metastasis of an ependymoma: a rare occurrence.

Extraneural metastases of ependymoma are very rare, and have been reported in the lungs, lymph nodes, pleura, mediastinum, liver, diaphragmatic muscle, and bone. We describe the radiological findings of pathologically proven lung metastases from an anaplastic ependymoma. The tumor which arose in the posterior fossa was first diagnosed in 2007 when first surgical resection was performed outside our institute. Multiple operations were performed after that due to tumor relapse. Multiple lung nodules were discovered incidentally during a VP shunt survey. Biopsy from the lung nodules displayed identical histomorphology to the primary brain tumor.

Intrahepatic splenosis mimicking hepatocellular carcinoma in a cirrhotic liver.

We report a patient who has a cirrhotic liver secondary to hepatitis C virus infection with a liver lesion incidentally found on routine liver ultrasound. The patient had a history of splenectomy 30 years earlier. The magnetic resonance imaging (MRI) characteristics suggested the diagnosis of intrahepatic splenosis, which is confirmed by core needle biopsy. Knowledge of these imaging findings makes this entity important to be considered in the differential diagnosis of a hepatic tumor in the presence of a history of splenic trauma or surgery.