Noonan Syndrome and Stroke: A Case Report

Noonan syndrome is an autosomal dominant genetic disease characterized by short stature, webbed neck, typical facial appearance and congenital heart disease. Here we report a 24 year old woman patient with the diagnosis of Noonan syndrome who admitted to our clinic with ischemic stroke caused by atrial fibrillation secondary to hypertrophic cardiomyopathy. Noonan syndrome patients with stroke due to vascular malformations have been reported, but non-obstructive hypertrophic cardiomyopathy is a rare cause for stroke in patients with Noonan syndrome. Our aim of presenting the case emphasize that Noonan syndrome should be thought as a differential diagnosis in patients with stroke at a young age and dysmorphic facial appearance

Graph-theoretic analysis of epileptic seizures on scalp EEG recordings

This work presents a novel modeling of neuronal activity of the brain by capturing the synchronization of EEG signals along the scalp. The pair-wise correspondence between elec-trodes recording EEG signals are used to establish edges be-tween these electrodes which then become the nodes of a syn-chronization graph. As EEG video signals are recorded over time, we discretize the time axis into overlapping epochs, and build a series of time-evolving synchronization graphs for each epoch and for each traditional frequency band. We show that graph theory provides a rich set of graph features that can be used for mining and learning from the EEG signals to determine temporal and spatial localization of epileptic seizures. We present several techniques to cap-ture the pair-wise synchronization and apply unsupervised learning algorithms, such as k-means clustering and multi-way modeling of third-order tensors, to analyze the labeled clinical data in the feature domain to detect the onset and origin location of the seizure. We use k-means clustering on two-way feature matrices for detection of seizures, and Tucker3 tensor decomposition for localization of seizures. We conduct an extensive parametric search to determine the best configuration of the model parameters including epoch length, synchronization metrics, and frequency bands, to achieve the highest accuracy. Our results are promising: we are able to detect the onset of seizure with an accuracy of 88.24%, and localize the onset of the seizure with an accuracy of 76.47%

Interleukin-1β secretion in hippocampal sclerosis patients with mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a common medically intractable epilepsy syndrome. Although pathogenesis of HS still remains highly controversial, genetics may play a role as a predisposing factor. Previous evidence in a Japanese population revealed that the homozygotes for allele T at position −511 of the interleukin (IL)-1β gene promoter region (IL-1β-511 T/T) confers susceptibility to the development of HS. However, whether this polymorphism has an effect on IL-1β levels in MTLE-HS patients was not demonstrated. This study aimed to analyze the distribution of this particular polymorphism in a group of Turkish HS patients and correlate the polymorphism with IL-1β secretion from the lymphocytes, thus revealing a functional role for IL-1β in the etiopathogenesis of HS. A single base pair polymorphism at position −511 in the promoter region of the IL-1β gene was analyzed. The spontaneous and 1 ng/mL lipopolysaccharide-stimulated production of IL-1β by peripheral blood mononuclear cells after 4 and 24 h of incubation were measured by ELISA method. The heterozygous type (−511 C/T) was the most common genotype. There was no difference in frequency of allele −511 T between patients and controls. Analysis of IL-1β levels, genotype and allele distributions showed no significant difference among the groups (P>0.05). Nevertheless, it was seen that patients who carry a T allele at position -511 of the IL-1β gene had increased IL-1β levels. T-allele carriage may be important. Only IL-1β secretion from the lymphocytes has been assessed in this study. Considering the importance of IL-1β in the etiopathogenesis of HS, further studies are needed to evaluate locally produced IL-1β levels

Brain Malformations Associated With Knobloch Syndrome-Review of Literature, Expanding Clinical Spectrum, and Identification of Novel Mutations

BACKGROUND: Knobloch syndrome is a rare, autosomal recessive, developmental disorder characterized by stereotyped ocular abnormalities with or without occipital skull deformities (encephalocele, bone defects, and cutis aplasia). Although there is clear heterogeneity in clinical presentation, central nervous system malformations, aside from the characteristic encephalocele, have not typically been considered a component of the disease phenotype. METHODS: Four patients originally presented for genetic evaluation of symptomatic structural brain malformations. Whole-genome genotyping, whole-exome sequencing, and confirmatory Sanger sequencing were performed. Using immunohistochemical analysis, we investigated the protein expression pattern of COL18A1 in the mid-fetal and adult human cerebral cortex and then analyzed the spatial and temporal changes in the expression pattern of COL18A1 during human cortical development using the Human Brain Transcriptome database. RESULTS: We identified two novel homozygous deleterious frame-shift mutations in the COL18A1 gene. On further investigation of these patients and their families, we found that many exhibited certain characteristics of Knobloch syndrome, including pronounced ocular defects. Our data strongly support an important role for COL18A1 in brain development, and this report contributes to an enhanced characterization of the brain malformations that can result from deficiencies of collagen XVIII. CONCLUSIONS: This case series highlights the diagnostic power and clinical utility of whole-exome sequencing technology allowing clinicians and physician scientists to better understand the pathophysiology and presentations of rare diseases. We suggest that patients who are clinically diagnosed with Knobloch syndrome and/or found to have COL18A1. mutations via genetic screening should be investigated for potential structural brain abnormalities even in the absence of an encephalocele

Brain Malformations Associated With Knobloch Syndrome—Review of Literature, Expanding Clinical Spectrum, and Identification of Novel Mutations

BACKGROUND: Knobloch syndrome is a rare, autosomal recessive, developmental disorder characterized by stereotyped ocular abnormalities with or without occipital skull deformities (encephalocele, bone defects, cutis aplasia). Although there is clear heterogeneity in clinical presentation, central nervous system malformations, aside from the characteristic encephalocele, have not typically been considered a component of the disease phenotype. METHODS: Four patients originally presented for genetic evaluation of symptomatic structural brain malformations. Whole-genome genotyping, whole-exome sequencing, and confirmatory Sanger sequencing were performed. Using immunohistochemical analysis, we investigated the protein expression pattern of COL18A1 in the mid-fetal and adult human cerebral cortex and then analyzed the spatial and temporal changes in the expression pattern of COL18A1 during human cortical development using the Human Brain Transcriptome database. RESULTS: We identified two novel homozygous deleterious frame-shift mutations in the COL18A1 gene. Upon further investigation of these patients and their families, we found that many exhibited certain characteristics of Knobloch syndrome, including pronounced ocular defects. Our data strongly support an important role for COL18A1 in brain development and this report contributes to an enhanced characterization of the brain malformations that can result from deficiencies of collagen XVIII. CONCLUSIONS: This case series highlights the diagnostic power and clinical utility of whole-exome sequencing technology – allowing clinicians and physician scientists to better understand the pathophysiology and presentations of rare diseases. We suggest that patients who are clinically diagnosed with Knobloch syndrome and/or found to have COL18A1 mutations via genetic screening should be investigated for potential structural brain abnormalities even in the absence of encephaloceles