Exome Sequencing Reveals Novel Variants and Expands the Genetic Landscape for Congenital Microcephaly.

Congenital microcephaly causes smaller than average head circumference relative to age, sex and ethnicity and is most usually associated with a variety of neurodevelopmental disorders. The underlying etiology is highly heterogeneous and can be either environmental or genetic. Disruption of any one of multiple biological processes, such as those underlying neurogenesis, cell cycle and division, DNA repair or transcription regulation, can result in microcephaly. This etiological heterogeneity manifests in a clinical variability and presents a major diagnostic and therapeutic challenge, leaving an unacceptably large proportion of over half of microcephaly patients without molecular diagnosis. To elucidate the clinical and genetic landscapes of congenital microcephaly, we sequenced the exomes of 191 clinically diagnosed patients with microcephaly as one of the features. We established a molecular basis for microcephaly in 71 patients (37%), and detected novel variants in five high confidence candidate genes previously unassociated with this condition. We report a large number of patients with mutations in tubulin-related genes in our cohort as well as higher incidence of pathogenic mutations in MCPH genes. Our study expands the phenotypic and genetic landscape of microcephaly, facilitating differential clinical diagnoses for disorders associated with most commonly disrupted genes in our cohort.

Pneumococcal Meningitis and Its Sequelae - A Devastating CNS Disease.

INTRODUCTION: In countries where Haemophilus influenzae type B vaccine is used, Streptococcus pneumoniae is the most common cause of bacterial meningitis in young children and notable cause of morbidity/mortality. The authors present material of magnetic resonance imaging (MRI) of patients with pneumococcal meningitis from archive of Department of Diagnostic Imaging of Institute of Mother and Child in Warsaw. MATERIALS AND METHODS: We performed 27 brain MRI scans and 1 follow-up computed tomography (CT) in 10 children (2 girls and 8 boys) aged from neonate to 5 years at disease onset with proven pneumococcal infection. RESULTS: Follow-up period range was 0-12 years. Two children underwent only one MRI, one of them died before follow-up and the other was lost from further observation. There was one case of relatively benign disease course with mild changes on MRI. In another seemingly benign case, acute transient hydrocephalus was observed. Six children developed hydrocephalus, and two required ventriculoperitoneal shunting complicated by neuroinfection, shunt malfunction and revisions. Two patients developed epilepsy. In six children, spastic paresis of various severity was diagnosed, up to quadriplegia in one who is under the longest observation (>12 years) and survived in vegetative state. Three other children suffer from delayed psychomotor development to severe intellectual disability. CONCLUSIONS: MRI shows perfectly the degree of central nervous system (CNS) damage during and after pneumococcal invasion. Despite appropriate treatment, disease course may be unpredictably serious. Attempts to eliminate the obligation to vaccinate are extremely irresponsible taking into account potential danger of death, vegetative state or another form of severe damage to CNS. Social and financial costs of care of survivors are very high with shunts placements and changes, (neuro)infections, rehabilitation, families breakdown, etc.

Intrathecal Infusion of Autologous Adipose-Derived Regenerative Cells in Autoimmune Refractory Epilepsy: Evaluation of Safety and Efficacy.

Objective/Purpose. Evaluation of efficacy and safety of autologous adipose-derived regenerative cells (ADRCs) treatment in autoimmune refractory epilepsy. Patients. Six patients with proven or probable autoimmune refractory epilepsy (2 with Rasmussen encephalitis, 2 with antineuronal autoantibodies in serum, and 2 with possible FIRES) were included in the project with approval of the Bioethics Committee. METHOD: Intrathecal injection of autologous ADRC acquired through liposuction followed by enzymatic isolation was performed. The procedure was repeated 3 times every 3 months with each patient. Neurological status, brain MRI, cognitive function, and antiepileptic effect were monitored during 12 months. RESULTS: Immediately after the procedure, all patients were in good condition. In some cases, transient mildly elevated body temperature, pain in regions of liposuction, and slight increasing number of seizures during 24 hours were observed. During the next months, some improvements in school, social functioning, and manual performance were observed in all patients. One patient has been seizure free up to the end of trial. In other patients, frequency of seizures was different: from reduced number to the lack of improvement (3-year follow-up). CONCLUSION: Autologous ADRC therapy may emerge as a promising option for some patients with autoimmune refractory epilepsy. Based on our trial and other clinical data, the therapy appears to be safe and feasible. Antiepileptic efficacy proved to be various; however, some abilities improved in all children. No signs of psychomotor regression were observed during the first year following the treatment.

Next-generation sequencing study reveals the broader variant spectrum of hereditary spastic paraplegia and related phenotypes.

Hereditary spastic paraplegias (HSPs) are clinically and genetically heterogeneous neurodegenerative disorders. Numerous genes linked to HSPs, overlapping phenotypes between HSP subtypes and other neurodegenerative disorders and the HSPs' dual mode of inheritance (both dominant and recessive) make the genetic diagnosis of HSPs complex and difficult. Out of the original HSP cohort comprising 306 index cases (familial and isolated) who had been tested according to "traditional workflow/guidelines" by Multiplex Ligation-dependent Probe Amplification (MLPA) and Sanger sequencing, 30 unrelated patients (all familial cases) with unsolved genetic diagnoses were tested using next-generation sequencing (NGS). One hundred thirty-two genes associated with spastic paraplegias, hereditary ataxias and related movement disorders were analysed using the Illumina TruSight™ One Sequencing Panel. The targeted NGS data showed pathogenic variants, likely pathogenic variants and those of uncertain significance (VUS) in the following genes: SPAST (spastin, SPG4), ATL1 (atlastin 1, SPG3), WASHC5 (SPG8), KIF5A (SPG10), KIF1A (SPG30), SPG11 (spatacsin), CYP27A1, SETX and ITPR1. Out of the nine genes mentioned above, three have not been directly associated with the HSP phenotype to date. Considering the phenotypic overlap and joint cellular pathways of the HSP, spinocerebellar ataxia (SCA) and amyotrophic lateral sclerosis (ALS) genes, our findings provide further evidence that common genetic testing may improve the diagnostics of movement disorders with a spectrum of ataxia-spasticity signs.

Comprehensive genomic analysis of patients with disorders of cerebral cortical development.

Malformations of cortical development (MCDs) manifest with structural brain anomalies that lead to neurologic sequelae, including epilepsy, cerebral palsy, developmental delay, and intellectual disability. To investigate the underlying genetic architecture of patients with disorders of cerebral cortical development, a cohort of 54 patients demonstrating neuroradiologic signs of MCDs was investigated. Individual genomes were interrogated for single-nucleotide variants (SNV) and copy number variants (CNV) with whole-exome sequencing and chromosomal microarray studies. Variation affecting known MCDs-associated genes was found in 16/54 cases, including 11 patients with SNV, 2 patients with CNV, and 3 patients with both CNV and SNV, at distinct loci. Diagnostic pathogenic SNV and potentially damaging variants of unknown significance (VUS) were identified in two groups of seven individuals each. We demonstrated that de novo variants are important among patients with MCDs as they were identified in 10/16 individuals with a molecular diagnosis. Three patients showed changes in known MCDs genes  and a clinical phenotype beyond the usual characteristics observed, i.e., phenotypic expansion, for a particular known disease gene clinical entity. We also discovered 2 likely candidate genes, CDH4, and ASTN1, with human and animal studies supporting their roles in brain development, and 5 potential candidate genes. Our findings emphasize genetic heterogeneity of MCDs disorders and postulate potential novel candidate genes involved in cerebral cortical development.

[Regression of cystic lesions on brain MRI in a child with hypoxic-ischemic encephalopathy treated with selective head cooling]. / Regresja zmian torbielowatych w obrazie MR mozgu u dziecka z noworodkowa encefalopatia niedotlenieniowo-niedokrwienna, poddanego hipotermii leczniczej.

The authors present the first case of regression of cystic lesions on brain MRI in a newborn after therapeutic hypothermia in Poland. Multicystic encephalopathy is the most severe form of hypoxic-ischemic encephalopathy and its regression is described very rarely in the literature. Magnetic resonance imaging is an accepted, optimal method of evaluation of the brain and establishing prognosis in children with HIE. After normal pregnancy an emergency cesarean section was performed at 37 weeks gestation due to the markers of intrauterine hypoxia on CTG. The condition of the newborn was serious: 3, 5, 7, 8 points according to Apgar score in 1st, 3nd, 5th and 10th minute of life, respectively. The infant required resuscitation. The cooling procedure lasted 72 hours. The first MRI study was performed at the age of 3 weeks and revealed cavities in the frontal and parietal lobed. The Evans index was 0.33. The second MRI investigation was carried out at the age of 5 weeks. The cavitary appearance did not change, the Evans index decreased to 0.32. The child underwent third MRI at the age of 2 years 4 months. No cystic lesions were found. There were signs of gliosis in their place and focal cortical-subcortical atrophy. The Evans index was 0.28 (within the normal limits). The neuropsychological status of the child at the age of 2.5 years is normal and brain MRI reveals strikingly mild lesions as compared to cavitary injury reported at the age of 3 and 5 weeks. The presented case shows that severe hypoxic-ischemic lesions such as cavities in an infant after cooling procedure do not necessarily mean poor prognosis, as with time even such lesions may regress. Therefore, even after the MRI diagnosis of multicystic encephalopathy the prognosis should be made with care.

Application of array comparative genomic hybridization in 102 patients with epilepsy and additional neurodevelopmental disorders.

Copy-number variants (CNVs) collectively represent an important cause of neurodevelopmental disorders such as developmental delay (DD)/intellectual disability (ID), autism, and epilepsy. In contrast to DD/ID, for which the application of microarray techniques enables detection of pathogenic CNVs in -10-20% of patients, there are only few studies of the role of CNVs in epilepsy and genetic etiology in the vast majority of cases remains unknown. We have applied whole-genome exon-targeted oligonucleotide array comparative genomic hybridization (array CGH) to a cohort of 102 patients with various types of epilepsy with or without additional neurodevelopmental abnormalities. Chromosomal microarray analysis revealed 24 non-polymorphic CNVs in 23 patients, among which 10 CNVs are known to be clinically relevant. Two rare deletions in 2q24.1q24.3, including KCNJ3 and 9q21.13 are novel pathogenic genetic loci and 12 CNVs are of unknown clinical significance. Our results further support the notion that rare CNVs can cause different types of epilepsy, emphasize the efficiency of detecting novel candidate genes by whole-genome array CGH, and suggest that the clinical application of array CGH should be extended to patients with unexplained epilepsies.

Recurrent distal 7q11.23 deletion including HIP1 and YWHAG identified in patients with intellectual disabilities, epilepsy, and neurobehavioral problems.

We report 26 individuals from ten unrelated families who exhibit variable expression and/or incomplete penetrance of epilepsy, learning difficulties, intellectual disabilities, and/or neurobehavioral abnormalities as a result of a heterozygous microdeletion distally adjacent to the Williams-Beuren syndrome region on chromosome 7q11.23. In six families with a common recurrent ∼1.2 Mb deletion that includes the Huntingtin-interacting protein 1 (HIP1) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein gamma (YWHAG) genes and that is flanked by large complex low-copy repeats, we identified sites for nonallelic homologous recombination in two patients. There were no cases of this ∼1.2 Mb distal 7q11.23 deletion copy number variant identified in over 20,000 control samples surveyed. Three individuals with smaller, nonrecurrent deletions (∼180-500 kb) that include HIP1 but not YWHAG suggest that deletion of HIP1 is sufficient to cause neurological disease. Mice with targeted mutation in the Hip1 gene (Hip1⁻(/)⁻) develop a neurological phenotype characterized by failure to thrive, tremor, and gait ataxia. Overall, our data characterize a neurodevelopmental and epilepsy syndrome that is likely caused by recurrent and nonrecurrent deletions, including HIP1. These data do not exclude the possibility that YWHAG loss of function is also sufficient to cause neurological phenotypes. Based on the current knowledge of Hip1 protein function and its proposed role in AMPA and NMDA ionotropic glutamate receptor trafficking, we believe that HIP1 haploinsufficiency in humans will be amenable to rational drug design for improved seizure control and cognitive and behavioral function.

[Clinical usefulness of serial EEG examinations in the diagnostic of hereditary epileptic encephalopathies case of severe epileptic encephalopathy type 2]. / Przydatnosc kliniczna seryjnych badan EEG w diagnostyce genetycznie uwarunkowanych encefalopatii padaczkowych na przykladzie przypadku ciezkiej encefalopatii padaczkowej typu 2.

BACKGROUND: Molecular studies allow to study background of many epilepsy types but qualification for genotyping is not easy, especially in initial stages of severe encephalopathy in newborns and infants. One of them is a type 2 severe epileptic encephalopathy (EIEE2), caused by dominant mutation in CDKL5 gene (Xp22.3). In this type of encephalopathy appearing mainly in females, treatment resistant epileptic seizures occur in the first two months of life, they are polymorphic-generalized or focal. Psychomotor development is significantly impaired and in course of time phenotype shows similarities to an Angelman syndrome or an atypical severe form of Rett syndrome. Correlation between clinical status and repeating EEG might be a diagnostic indicator for looking for CDKL5 gene mutation. AIM: We report a case of 3.5 years old girl with refractory epilepsy and dysmorphia like in Angelman syndrome. Mutation in CDKL5 gene was supposed during clinical observation and EEG examination and finally was confirmed. CASE REPORT: Family history and fetal & perinatal history were negative. The patient suffered from treatment resistant polymorphic epileptic seizures appearing from 3 months of life. Psychomotor impairment, significant flaccidity and microcephaly were observed from early infant period. Additionally, pale complexion, always opened mouth, protruding tongue, prognathia, wide-spaced teeth, frequent laughter/smiling were seen. Brain MRI (including MRS) was normal. Repeating EEG showed evolution from normal during infantile spasms to multifocal discharges and loss of sleep spindles. Metabolic disorders, Angelman and Rett syndromes were excluded. Finally, mutation in CDKL5 gene was confirmed at the age of 2.5 into genetic counseling. CONCLUSIONS: There is a need to correlate phenotype features and sequential EEG and epileptic seizures evolution to determine indication for genotyping. Genetic testing looking for CDKL5 mutation is indicated in each female child with impaired psychomotor development, refractory epilepsy with early onset polymorphic seizures and clinical & EEG phenotype of atypical Rett/Angelman syndrome.