Detection of Transient Increase of Cerebral Blood Flow and Reversible Neuronal Dysfunction by Iodine-123-Iomazenil Single Photon Emission Computed Tomography After Cerebral Hyperperfusion Syndrome After Revascularization Surgery for Moyamoya Disease.

BACKGROUND: Early and late images of single photon emission computed tomography (SPECT) using 123I-iomazenil (123I-IMZ) can demonstrate cerebral blood flow and cortical neuronal viability. Hyperperfusion syndrome is one of the serious complications after revascularization surgery for moyamoya disease; therefore, the real-time observation of the hemodynamics and neuronal viability is important for the treatment after the revascularization. Here we report, a case of moyamoya disease where 123I-IMZ SPECT had a significant efficacy to delineate the hemodynamics and transient neuronal dysfunction in hyperperfusion state after revascularization. CASE DESCRIPTION: A 47-year-old woman presented with motor aphasia 3 days after superficial temporal artery-middle cerebral artery anastomosis with indirect revascularization. Magnetic resonance imaging (MRI) on the same day showed no new ischemic changes but high intensities along the left frontal sulci observed on fluid-attenuated inversion recovery images, and 123I-IMZ SPECT demonstrated the increased uptake on the early images and the decreased uptake on the late images around the anastomosis site. The patient was completely recovered 1 month after surgery, and abnormal changes on MRI and 123I-IMZ SPECT returned to normal along with the symptom withdrawal. CONCLUSIONS: These findings indicate that 123I-IMZ SPECT could be the index for the treatment of revascularization for obstructive vascular diseases such as moyamoya disease.

Author Correction: A missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria, and cleft palate.

Since the publication of this article, it has been brought to our attention, that the identified mutation (NM_015277: c.2617 G > A; p.Glu873Lys) is identical with the mutation (NM_001144967: c.2677 G > A; p.Glu893Lys) reported by Broix et al (Nature Genetics 48, 1349-1358, 2016 https://doi.org/10.1038/ng.3676 ). Therefore the mutation is not novel but recurrent. Accordingly, the word "novel" should be deleted throughout the article including the title. Thus, the title should read "A missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria, and cleft palate."

Publisher Correction: IMSindel: An accurate intermediate-size indel detection tool incorporating de novo assembly and gapped global-local alignment with split read analysis.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

A novel homozygous missense mutation in the SH3-binding motif of STAMBP causing microcephaly-capillary malformation syndrome.

Microcephaly-capillary malformation syndrome is a congenital and neurodevelopmental disorder caused by biallelic mutations in the STAMBP gene. Here we identify the novel homozygous mutation located in the SH3 binding motif of STAMBP (NM_006463.4) (c.707C>T: p.Ser236Phe) through whole-exome sequencing. The case patient was a 2-year-old boy showing severe global developmental delay, progressive microcephaly, refractory seizures, dysmorphic facial features, and multiple capillary malformations. Immunoblot analysis of patient-derived lymphoblastoid cell lines (LCLs) revealed a severe reduction in STAMBP expression, indicating that Ser236Phe induces protein instability. STAMBP interacts with the SH3 domain of STAM and transduces downstream signals from the Jaks-STAM complex. The substitution of Ser236Phe found in the case patient was located in the SH3-binding motif, and we propose the mutation may block STAM binding and subsequently induce STAMBP degradation. Contrary to previously reported STAMBP mutations, the Ser236Phe mutation did not lead to constitutive activation of the PI3K-AKT-mTOR pathway in patient-derived LCLs, as indicated by the expression of phosphorylated S6 ribosomal protein, suggesting that it is not the major pathomechanism underlying the disorder in this patient.

IMSindel: An accurate intermediate-size indel detection tool incorporating de novo assembly and gapped global-local alignment with split read analysis.

Insertions and deletions (indels) have been implicated in dozens of human diseases through the radical alteration of gene function by short frameshift indels as well as long indels. However, the accurate detection of these indels from next-generation sequencing data is still challenging. This is particularly true for intermediate-size indels (≥50 bp), due to the short DNA sequencing reads. Here, we developed a new method that predicts intermediate-size indels using BWA soft-clipped fragments (unmatched fragments in partially mapped reads) and unmapped reads. We report the performance comparison of our method, GATK, PINDEL and ScanIndel, using whole exome sequencing data from the same samples. False positive and false negative counts were determined through Sanger sequencing of all predicted indels across these four methods. The harmonic mean of the recall and precision, F-measure, was used to measure the performance of each method. Our method achieved the highest F-measure of 0.84 in one sample, compared to 0.56 for GATK, 0.52 for PINDEL and 0.46 for ScanIndel. Similar results were obtained in additional samples, demonstrating that our method was superior to the other methods for detecting intermediate-size indels. We believe that this methodology will contribute to the discovery of intermediate-size indels associated with human disease.

Generation of Induced Pluripotent Stem Cells and Neural Stem/Progenitor Cells from Newborns with Spina Bifida Aperta.

STUDY DESIGN: We established induced pluripotent stem cells (iPSCs) and neural stem/progenitor cells (NSPCs) from three newborns with spina bifida aperta (SBa) using clinically practical methods. PURPOSE: We aimed to develop stem cell lines derived from newborns with SBa for future therapeutic use. OVERVIEW OF LITERATURE: SBa is a common congenital spinal cord abnormality that causes defects in neurological and urological functions. Stem cell transplantation therapies are predicted to provide beneficial effects for patients with SBa. However, the availability of appropriate cell sources is inadequate for clinical use because of their limited accessibility and expandability, as well as ethical issues. METHODS: Fibroblast cultures were established from small fragments of skin obtained from newborns with SBa during SBa repair surgery. The cultured cells were transfected with episomal plasmid vectors encoding reprogramming factors necessary for generating iPSCs. These cells were then differentiated into NSPCs by chemical compound treatment, and NSPCs were expanded using neurosphere technology. RESULTS: We successfully generated iPSC lines from the neonatal dermal fibroblasts of three newborns with SBa. We confirmed that these lines exhibited the characteristics of human pluripotent stem cells. We successfully generated NSPCs from all SBa newborn-derived iPSCs with a combination of neural induction and neurosphere technology. CONCLUSIONS: We successfully generated iPSCs and iPSC-NSPCs from surgical samples obtained from newborns with SBa with the goal of future clinical use in patients with SBa.

A novel genetic syndrome with STARD9 mutation and abnormal spindle morphology.

Intellectual disability (ID) is one of neurodevelopmental disorders characterized by serious defects in both intelligence and adaptive behavior. Although it has been suggested that genetic aberrations associated with the process of cell division underlie ID, the cytological evidence for mitotic defects in actual patient's cells is rarely reported. Here, we report a novel mutation in the STARD9 (also known as KIF16A) gene found in a patient with severe ID, characteristic features, epilepsy, acquired microcephaly, and blindness. Using whole-exome sequence analysis, we sequenced potential candidate genes in the patient. We identified a homozygous single-nucleotide deletion creating a premature stop codon in the STARD9 gene. STARD9 encodes a 4,700 amino acid protein belonging to the kinesin superfamily. Depletion of STARD9 or overexpression of C-terminally truncated STARD9 mutants were known to induce spindle assembly defects in human culture cells. To determine cytological features in the patient cells, we isolated lymphoblast cells from the patient, and performed immunofluorescence analysis. Remarkably, mitotic defects, including multipolar spindle formation, fragmentation of pericentriolar materials and centrosome amplification, were observed in the cells. Taken together, our findings raise the possibility that controlled expression of full-length STARD9 is necessary for proper spindle assembly in cell division during human development. We propose that mutations in STARD9 result in abnormal spindle morphology and cause a novel genetic syndrome with ID.

Visualization of migration of human cortical neurons generated from induced pluripotent stem cells.

BACKGROUND: Neuronal migration is considered a key process in human brain development. However, direct observation of migrating human cortical neurons in the fetal brain is accompanied by ethical concerns and is a major obstacle in investigating human cortical neuronal migration. NEW METHOD: We established a novel system that enables direct visualization of migrating cortical neurons generated from human induced pluripotent stem cells (hiPSCs). RESULTS: We observed the migration of cortical neurons generated from hiPSCs derived from a control and from a patient with lissencephaly. METHODS: Our system needs no viable brain tissue, which is usually used in slice culture. Migratory behavior of human cortical neuron can be observed more easily and more vividly by its fluorescence and glial scaffold than that by earlier methods. CONCLUSIONS: Our in vitro experimental system provides a new platform for investigating development of the human central nervous system and brain malformation.

Systemic Intravenous Adoptive Transfer of Autologous Lymphokine-activated αß T-Cells Improves Temozolomide-induced Lymphopenia in Patients with Glioma.

In this clinical study, we investigated the safety and clinical usefulness of systemic adoptive immunotherapy using autologous lymphokine-activated αß T-cells (αß T-cells), combined with standard therapies, in patients with malignant brain tumors. Twenty-three patients with different malignant brain tumors, consisting of 14 treated with temozolomide (TMZ group) and 9 treated without temozolomide (non-TMZ group), received systemic intravenous injections of αß T-cells (mean=10.4 injections/patient for the TMZ group, and 4.78 for the non-TMZ group). No significant adverse effects associated with the αß T-cell injection were observed, and the total lymphocyte count (TLC) improved significantly in the TMZ group after five injections. Furthermore, CD8-positive or T-cell receptor V gamma -positive cells were increased with TLC in three patients with glioblastoma multiforme. These findings suggest that systemic αß T-cell immunotherapy is well tolerated, and may help restore an impaired and imbalanced T-cell immune status, and temozolomide- and/or radiotherapy-induced lymphopenia. Future prospective study is needed to clarify the clinical merits of this immunotherapy.

Siblings with optic neuropathy and RTN4IP1 mutation.

Inherited optic neuropathies (IONs) are neurodegenerative disorders affecting the optic nerve and the nervous system. Dominant and recessive IONs are known. Many of the dominant IONs are caused by mutations of OPA1. Autosomal-recessive IONs are rare. OPA10 is an autosomal-recessive ION due to mutations in RTN4IP1. Patients with RTN4IP1 mutations show extraocular manifestations. We report brothers with optic neuropathy who had novel mutations in the RTN4IP1 gene. This is the first report of Japanese patients with OPA10. They showed extraocular manifestations resembling mitochondrial encephalopathy.

Defects in autophagosome-lysosome fusion underlie Vici syndrome, a neurodevelopmental disorder with multisystem involvement.

Vici syndrome (VICIS) is a rare, autosomal recessive neurodevelopmental disorder with multisystem involvement characterized by agenesis of the corpus callosum, cataracts, cardiomyopathy, combined immunodeficiency, developmental delay, and hypopigmentation. Mutations in EPG5, a gene that encodes a key autophagy regulator, have been shown to cause VICIS, however, the precise pathomechanism underlying VICIS is yet to be clarified. Here, we describe detailed clinical (including brain MRI and muscle biopsy) and genetic features of nine Japanese patients with VICIS. Genetic dissection of these nine patients from seven families identified 14 causative mutations in EPG5. These included five nonsense, two frameshift, three splicing, one missense, and one multi-exon deletion mutations, and two initiation codon variants. Furthermore, cultured skin fibroblasts (SFs) from two affected patients demonstrated partial autophagic dysfunction. To investigate the function of EPG5, siRNA based EPG5 knock-down, and CRISPR/Cas9 mediated EPG5 knock-out HeLa cells were generated. EPG5-depleted cells exhibited a complete block of autophagic flux caused by defective autophagosome-lysosome fusion. Unexpectedly, endocytic degradation was normal in both VICIS SFs and EPG5 depleted cells, suggesting that EPG5 function is limited to the regulation of autophagosome-lysosome fusion.

A novel missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria and cleft palate.

We identified a novel de novo heterozygous missense mutation in the NEDD4L gene (NM_015277: c.2617G>A; p.Glu873Lys) through whole-exome sequencing in a 3-year-old girl showing severe global developmental delay, infantile spasms, cleft palate, periventricular nodular heterotopia and polymicrogyria. Mutations in the HECT domain of NEDD4L have been reported in patients with a neurodevelopmental disorder along with similar brain malformations. All patients reported with NEDD4L HECT domain mutations showed periventricular nodular heterotopia, and most had seizures, cortex anomalies, cleft palate and syndactyly. The unique constellation of clinical features in patients with NEDD4L mutations might help clinically distinguish them from patients with other genetic mutations including FLNA, which is a well-known causative gene of periventricular nodular heterotopia. Although mutations in the HECT domain of NEDD4L that lead to AKT-mTOR pathway deregulation in forced expression system were reported, our western blot analysis did not show an increased level of AKT-mTOR activity in lymphoblastoid cell lines (LCLs) derived from the patient. In contrast to the forced overexpression system, AKT-mTOR pathway deregulation in LCLs derived from our patient seems to be subtle.

Novel MCA/ID syndrome with ASH1L mutation.

We identified a novel mutation in ASH1L in a patient with severe intellectual disability, growth failure, microcephaly, facial dysmorphism, myelination delay, and skeletal abnormalities. ASH1L is a histone methyltransferase that associates with the transcribed region of all active genes examined, including Hox genes. It catalyzes H3K36 methylation and plays important roles in development. There has been increasing evidence that heterozygous mutation of ASH1L is associated with ID and autism spectrum disorders. We suggest that ASH1L abnormalities may cause a novel MCA/ID syndrome.

A combination of genetic and biochemical analyses for the diagnosis of PI3K-AKT-mTOR pathway-associated megalencephaly.

BACKGROUND: Constitutive activation of the PI3K-AKT-mTOR pathway (mTOR pathway) underlies megalencephaly in many patients. Yet, prevalence of the involvement of the PI3K-AKT-mTOR pathway in patients with megalencephaly remains to be elucidated, and molecular diagnosis is challenging. Here, we have successfully established a combination of genetic and biochemical methods for diagnosis of mTOR pathway-associated megalencephaly, and have attempted to delineate the clinical characteristics of the disorder. METHODS: Thirteen patients with an increased head circumference and neurological symptoms participated in the study. To evaluate the activation of the mTOR pathway, we performed western blot analysis to determine the expression levels of phosphorylated S6 ribosomal protein (phospho-S6 protein) in lymphoblastoid cell lines from 12 patients. Multiplex targeted sequencing analysis for 15 genes involved in the mTOR pathway was performed on 12 patients, and whole-exome sequencing was performed on one additional patient. Clinical features and MRI findings were also investigated. RESULTS: We identified pathogenic mutations in six (AKT3, 1 patient; PIK3R2, 2 patients; PTEN, 3 patients) of the 13 patients. Increased expression of phospho-S6 protein was demonstrated in all five mutation-positive patients in whom western blotting was performed, as well as in three mutation-negative patients. Developmental delay, dysmorphic facial features were observed in almost all patients. Syndactyly/polydactyly and capillary malformations were not observed, even in patients with AKT3 or PIK3R2 mutations. There were no common phenotypes or MRI findings among these patients. CONCLUSIONS: A combination of genetic and biochemical methods successfully identified mTOR pathway involvement in nine of 13 (approximately 70%) patients with megalencephaly, indicating a major contribution of the pathway to the pathogenesis of megalencephaly. Our combined approach could be useful to identify patients who are suitable for future clinical trials using an mTOR inhibitor.

Life and Medical Ethics in Pediatric Neurosurgery.

Ethical issues in the field of pediatric neurosurgery, including prenatal diagnosis, palliative care for children with an intractable serious disease, and medical neglect, are discussed. An important role of medicine is to offer every possible treatment to a patient. However, it also is the responsibility of medicine to be conscious of its limitations, and to help parents love and respect a child who suffers from an incurable disease. When dealing with cases of medical neglect and palliative care for an incurable disease, it is critical to diagnose the child's condition accurately and evaluate the outcome. However, to treat or not to treat also depends on the medical resources and social-economic status of the community, the parents' religion and philosophy, the policies of the institutions involved, and the limits of medical science. Moral dilemmas will continue to be addressed as medical progress yields treatments for untreatable diseases in the future.

Role of a heterotrimeric G-protein, Gi2, in the corticogenesis: possible involvement in periventricular nodular heterotopia and intellectual disability.

We analyzed the role of a heterotrimeric G-protein, Gi2, in the development of the cerebral cortex. Acute knockdown of the α-subunit (Gαi2) with in utero electroporation caused delayed radial migration of excitatory neurons during corticogenesis, perhaps because of impaired morphology. The migration phenotype was rescued by an RNAi-resistant version of Gαi2. On the other hand, silencing of Gαi2 did not affect axon elongation, dendritic arbor formation or neurogenesis at ventricular zone in vivo. When behavior analyses were conducted with acute Gαi2-knockdown mice, they showed defects in social interaction, novelty recognition and active avoidance learning as well as increased anxiety. Subsequently, using whole-exome sequencing analysis, we identified a de novo heterozygous missense mutation (c.680C>T; p.Ala227Val) in the GNAI2 gene encoding Gαi2 in an individual with periventricular nodular heterotopia and intellectual disability. Collectively, the phenotypes in the knockdown experiments suggest a role of Gαi2 in the brain development, and impairment of its function might cause defects in neuronal functions which lead to neurodevelopmental disorders.

Novel compound heterozygous variants in PLK4 identified in a patient with autosomal recessive microcephaly and chorioretinopathy.

It has been well documented that variants in genes encoding centrosomal proteins cause primary autosomal recessive microcephaly, although the association between centrosomal defects and the etiology of microcephaly syndromes is not fully understood. Polo-like kinase 4 (PLK4) is one of the centrosomal proteins required for centriole duplication. We here describe a patient with microcephaly and chorioretinopathy that harbors compound heterozygous missense variants, c.[442A>G]; [2336G>A], in the PLK4 gene. One of these variants, c.442A>G (p.(M148V)), resides in the kinase domain, and the other, c.2336G>A (p.(C779Y)), in the polo-box domain. Aberrant spindle formation was observed in a LCL derived from this patient. Overexpression experiments of the variant PLK4 proteins demonstrated that the p.(C779Y) but not the p.(M148V) had lost centriole overduplication ability. The altered mobility pattern of both variant proteins on a western blot further suggested alterations in post-translation modification. Our data lend support to the hypothesis that impaired centriole duplication caused by PLK4 variants may be involved in the etiology of microcephaly disorder.

A case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft.

INTRODUCTION: The incidence of facial cleft is rare and ranges between 1.43 and 4.85 per 100,000 births. To date, there have been few reports of detailed ophthalmologic examinations performed in cases of facial cleft. Here, we report a case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft. CASE REPORT: A 9-day-old female infant was delivered by cesarian section at 34 weeks of gestational age (the second baby of twins) and weighed 2,276 g upon presentation. She had a facial cleft and ectrodactyly at birth. Right eye-dominant blepharophimosis was obvious. Examination of the right eye revealed inferior corneal opacity with vascularization, downward corectopia, and optic-nerve hypoplasia. The corneal diameter was 8 mm in both eyes, and tonometry by use of a Tono-Pen(®) XL (Reichert Technologies, Depew, NY, USA) handheld applanation tonometer revealed that her intraocular pressure was 11-22 mmHg (Oculus Dexter) and 8 mmHg (Oculus Sinister). B-mode echo revealed no differences in axial length between her right and left eyes. When she was 15-16 months old, we attempted to examine her eyes before she underwent plastic surgery under general anesthesia. She had a small optic disc in both eyes and the right-eye disc was tilted. After undergoing canthotomy, gonioscopy and ultrasound biomicroscopy revealed that almost all directions were open except for the peripheral anterior synechia. Since magnetic resonance imaging revealed ventriculomegaly associated with an interhemispheric cyst at birth, a ventriculoperitoneal shunt was inserted at 12 days of age. At 25 months of age, her condition suddenly deteriorated due to occlusion of the ventricular shunt catheter, and she died 5 days later. In this patient, amniotic band syndrome was presumed to be the primary cause due to the clinical findings. CONCLUSION: We experienced a case of optic-nerve hypoplasia and anterior segment abnormality that occurred with facial cleft. The cause of these abnormalities is unclear, yet amniotic band syndrome is a possible candidate.

In vitro characterization of neurite extension using induced pluripotent stem cells derived from lissencephaly patients with TUBA1A missense mutations.

BACKGROUND: Lissencephaly, or smooth brain, is a severe congenital brain malformation that is thought to be associated with impaired neuronal migration during corticogenesis. However, the exact etiology of lissencephaly in humans remains unknown. Research on congenital diseases is limited by the shortage of clinically derived resources, especially for rare pediatric diseases. The research on lissencephaly is further limited because gyration in humans is more evolved than that in model animals such as mice. To overcome these limitations, we generated induced pluripotent stem cells (iPSCs) from the umbilical cord and peripheral blood of two lissencephaly patients with different clinical severities carrying alpha tubulin (TUBA1A) missense mutations (Patient A, p.N329S; Patient B, p.R264C). RESULTS: Neural progenitor cells were generated from these iPSCs (iPSC-NPCs) using SMAD signaling inhibitors. These iPSC-NPCs expressed TUBA1A at much higher levels than undifferentiated iPSCs and, like fetal NPCs, readily differentiated into neurons. Using these lissencephaly iPSC-NPCs, we showed that the neurons derived from the iPSCs obtained from Patient A but not those obtained from Patient B showed abnormal neurite extension, which correlated with the pathological severity in the brains of the patients. CONCLUSION: We established iPSCs derived from lissencephaly patients and successfully modeled one aspect of the pathogenesis of lissencephaly in vitro using iPSC-NPCs and iPSC-derived neurons. The iPSCs from patients with brain malformation diseases helped us understand the mechanism underlying rare diseases and human corticogenesis without the use of postmortem brains.

Working Conditions and Lifestyle of Female Surgeons Affiliated to the Japan Neurosurgical Society: Findings of Individual and Institutional Surveys.

To investigate the working conditions of female neurosurgeons in Japan, two surveys were conducted by The Japan Neurosurgical Society: one involving female neurosurgeons themselves and the other involving the chiefs of neurosurgical departments. The responses were received from 224 (43.8%) female neurosurgeons and 496 (61.2%) departmental chiefs. About half (50.2%) of the female neurosurgeons were married and 39.2% had children (average number of children, 1.27). Their work was full-time in 80.6% of cases; on average, they worked 51.9 h per week, had night duty 2.8 times per month, and had 5.7 days off per month. Many of them stated that they were satisfied with their job status, but about half of them reported difficulty in maintaining a correct work-life balance. Among the institutions surveyed, 29% had female neurosurgeons. The survey of departmental chiefs revealed that the proxies for maternity leave were not available at most institutions, and that there was only limited availability of night child care (41%) or sick child care (39%); female neurosurgeons did not appear to be well-informed of these support systems. These findings suggest that apart from systematic approaches already in place, female neurosurgeons would prefer to have more understanding from their peers and chiefs.