Whole-exome sequencing of a Saudi epilepsy cohort reveals association signals in known and potentially novel loci.

BACKGROUND: Epilepsy, a serious chronic neurological condition effecting up to 100 million people globally, has clear genetic underpinnings including common and rare variants. In Saudi Arabia, the prevalence of epilepsy is high and caused mainly by perinatal and genetic factors. No whole-exome sequencing (WES) studies have been performed to date in Saudi Arabian epilepsy cohorts. This offers a unique opportunity for the discovery of rare genetic variants impacting this disease as there is a high rate of consanguinity among large tribal pedigrees. RESULTS: We performed WES on 144 individuals diagnosed with epilepsy, to interrogate known epilepsy-related genes for known and functional novel variants. We also used an American College of Medical Genetics (ACMG) guideline-based variant prioritization approach in an attempt to discover putative causative variants. We identified 32 potentially causative pathogenic variants across 30 different genes in 44/144 (30%) of these Saudi epilepsy individuals. We also identified 232 variants of unknown significance (VUS) across 101 different genes in 133/144 (92%) subjects. Strong enrichment of variants of likely pathogenicity was observed in previously described epilepsy-associated loci, and a number of putative pathogenic variants in novel loci are also observed. CONCLUSION: Several putative pathogenic variants in known epilepsy-related loci were identified for the first time in our population, in addition to several potential new loci which may be prioritized for further investigation.

A Case of Trigeminal Schwannoma Presenting as a Parasellar Mass.

Schwannoma's of considerable size arising from the trigeminal nerve are very rare. Here, a case of a large right-sided parasellar mass diagnosed as a trigeminal schwannoma is reported. Complete resection of the tumor was successfully achieved. The patient had an excellent postoperative course.

Adult Desmoplastic Medulloblastoma.

Medulloblastoma is more common in young age and rare in adult age. Some characteristics that characterize medulloblastoma in adults compared with children: Lateral cerebellar location, heterogeneous signal intensity on magnetic resonance imaging, desmoplastic histological variant and more favorable prognosis. Preoperative diagnosis is important for correct management of these patients. However, because of the low incidence of medulloblastoma in adults, preoperative diagnosis still challenging and prognostic factors and best treatment options are still controversial. We report a case of a 31-year-old male patient who presented with a rare case of posterior fossa medulloblastoma.

Mixed vestibular schwannoma and meningioma without neurofibromatosis.

The co-existence of meningioma and schwannoma as 2 distinct histologic components within the same tumor has been described in neurofibromatosis 2 (NF2), but the co-existence of both tumors without evidence of NF2 is much rarer. Here, we are reporting a case of mixed schwannoma with meningioma without clinical evidence of NF2. In an adult Saudi lady with progressive left-sided hearing loss, left cerebellopontine tumor was diagnosed by MRI, and the histopathological diagnosis revealed that this tumor was composed of vestibular schwannoma and meningioma. This case is discussed with literature review.

Experience with severe head injury and role of intracranial pressure monitoring in Eastern Saudi Arabia.

OBJECTIVE: Severe head injury is the leading cause of death in the younger age group and it is an epidemic health problem in Saudi Arabia. Several factors contribute to this observation. These include socio-economic prosperity, poor driving behavior and attitudes. The study was conducted to determine the magnitude of severe head injury in the Eastern Province of the Kingdom of Saudi Arabia (KSA) and to emphasize the importance of application of intracranial pressure (ICP) monitoring in severe head injury. METHODS: A retrospective study of 178 patients admitted to King Fahad Hospital of the University, Al-Khobar, KSA during the period from 1992-2002 with severe head injury Glasgow coma score (GCS) <\=8 included the analysis and correlation of clinical and radiological factors such as age, sex, nationality, cause of the trauma, epilepsy, alcohol intake, extracranial injuries, x-ray findings, CT scan findings, surgical intervention, and application of the ICP monitor to the outcome. The data were subjected to detailed analysis using the Statistical Package for Social Sciences version 10. RESULTS: The study group was divided into 2; the first group consisted of patients treated without the application of the ICP monitor and consisted of 126 patients, and the outcome was satisfactory (good recovery or moderate disability) in 38% and 62% had poor outcome (severe disability or death). The second group was 52 patients where ICP monitor was used. Two thirds of them showed high ICP. The outcome in this group was satisfactory in 77% and poor in 23%. CONCLUSION: Severe head injury is a major health hazard leading to a high rate of morbidity, disability and death. The benefit of an ICP monitor should be clearly illustrated to all neurosurgical centers in KSA in order to consider routine and early applications of ICP monitoring as one of the basic measures in severely head injured patients.