ATP6AP2 variant impairs CNS development and neuronal survival to cause fulminant neurodegeneration.

Vacuolar H+-ATPase-dependent (V-ATPase-dependent) functions are critical for neural proteostasis and are involved in neurodegeneration and brain tumorigenesis. We identified a patient with fulminant neurodegeneration of the developing brain carrying a de novo splice site variant in ATP6AP2 encoding an accessory protein of the V-ATPase. Functional studies of induced pluripotent stem cell-derived (iPSC-derived) neurons from this patient revealed reduced spontaneous activity and severe deficiency in lysosomal acidification and protein degradation leading to neuronal cell death. These deficiencies could be rescued by expression of full-length ATP6AP2. Conditional deletion of Atp6ap2 in developing mouse brain impaired V-ATPase-dependent functions, causing impaired neural stem cell self-renewal, premature neuronal differentiation, and apoptosis resulting in degeneration of nearly the entire cortex. In vitro studies revealed that ATP6AP2 deficiency decreases V-ATPase membrane assembly and increases endosomal-lysosomal fusion. We conclude that ATP6AP2 is a key mediator of V-ATPase-dependent signaling and protein degradation in the developing human central nervous system.

Complejo Esclerosis Tuberosa Atípico Con Espasmos Epilépticos De Inicio Tardío: Diagnóstico Complejo Por Telemedicina En Una Comunidad Rural De Honduras / Atypical Tuberous Sclerosis Complex With Late Onset Epileptic Spasms: Complex Diagnosis By Telemedicine In A Rural Community Of Honduras

RESUMEN El complejo esclerosis tuberosa (CET) es una enfermedad neurocutánea infrecuente y subdiagnosticada en zonas remotas donde usualmente no hay neurólogos disponibles. Una niña de 22 meses fue llevada a una clínica en una comunidad rural por un cuadro de epilepsia refractaria de causa no determinada, de inicio a los 18 meses de edad con episodios de oculogiros y espasmos epilépticos en extensión. Además presentaba angiofibromas perinasales y lesiones hipomelanóticas en tronco. El encefalograma interictal hecho en la comunidad mostraba actividad epiléptica multifocal y generalizada. La niña había sido llevada a la ciudad para una resonancia cerebral, la cual reveló hiperintensidades subcorticales multifocales y nódulos subependimarios. Por teleconsulta entre médicos de la comunidad y especialistas nacionales e internacionales se diagnosticó CET atípico con espasmos epilépticos de inicio tardío. Se sugirió tratamiento que logró control de las crisis y se estableció un plan de seguimiento. El caso muestra que las unidades de telemedicina en zonas rurales son una opción tecnológica para brindar acceso a atención especializada de las epilepsias.

ABSTRACT Tuberous sclerosis complex (TSC) is an uncommon neurocutaneous disease often underdiagnosed in remote areas where specialists in neurology are usually not available. A 22 month-old girl was taken to a clinic in a rural village presenting refractory epilepsy of undetermined cause that started at 18 months of age with upward eye deviation episodes and epileptic extensor spasms. She also presented perinasal angiofibromas and hypomelanotic skin lesions in trunk. The interictal encephalogram done in the community showed multifocal and generalized epileptic activity. The girl had been taken to the city for a brain magnetic resonance, which revealed multifocal subcortical hyperintensities and subependymal nodules. By teleconsult between community doctors and national and international specialists, atypical TSC with late onset epileptic spasms was diagnosed. The recommended treatment resulted in controlled seizures, and a follow-up plan was established. This case illustrates that telemedicine units in rural areas are a technological option to provide access to specialized epilepsy care.

Transgenerational Inheritance of Familial Lipomyelomeningocele.

Lipomyelomeningocele is a type of neural tube defect characterized by lipomatous tissue causing a defect in the vertebrae, infiltrating the dura, and tethering the spinal cord. Despite significant neurologic consequences, the underlying etiology remains poorly understood. We present a father and son with remarkably similar presentations of lipomyelomeningocele. Genetic testing did not reveal an underlying cause but whole exome sequencing identified variants in the ARHGAP29 and RADIL genes in the proband and his affected father. Genetic analyses of asymptomatic family members revealed several carriers of the ARHGAP29 or RADIL variants, but only the proband and his father carried both variants, suggesting a possible shared genetic mechanism. Rare cases of siblings affected with lipomyelomeningocele have suggested the possibility of autosomal recessive or germline mosaicism. We present the first documented cases of transgenerational lipomyelomeningocele with important implications for family counseling about the recurrence of lipomyelomeningocele.

Feasibility of developing a pediatric telehealth network in Honduras with international consultation support.

INTRODUCTION: Honduras is the second poorest country in Central America, and roughly 50% of the population lives in rural areas. A telehealth network linking these areas to larger health centers may improve patient access to care, and physician access to educational opportunities. This pilot study assessed the feasibility of establishing a pediatric telehealth network between underserved clinics in Honduras and the Medical University of South Carolina (MUSC). METHODS: Two underserved Honduran clinics were identified and invited to participate in the telehealth network. Providers from these clinics connected remotely to educational conferences at MUSC, and received teleconsults from MUSC physicians and physicians from the other Honduran site. Honduran providers completed five-point Likert scale satisfaction surveys following participation in the conferences and teleconsults. RESULTS: Survey feedback was positive, with 100% of respondents stating they would utilize telemedicine in the future. Dissatisfaction was expressed subjectively in the survey comments with regards to poor Internet connectivity and unreliable electrical power. CONCLUSIONS: The establishment of a telehealth network between Honduras and MUSC is feasible, and rural providers were receptive to the clinical and educational opportunities this network provides. Future projects will expand telehealth capabilities to other Honduran sites and focus on intra-country collaboration to ensure sustainability.

Clinical Features and Neurologic Complications of Children Hospitalized With Chikungunya Virus in Honduras.

The first case of Chikungunya virus in Honduras was identified in 2014. The virus has spread widely across Honduras via the Aedes aegypti mosquito, leading to an outbreak of Chikungunya virus (CHIKV) in 2015 that significantly impacted children. A retrospective chart review of 235 children diagnosed with CHIKV and admitted to the National Autonomous University of Honduras Hospital Escuela (Hospital Escuela) in Tegucigalpa, Honduras, was accomplished with patients who were assessed for clinical features and neurologic complications. Of 235 children admitted to Hospital Escuela with CHIKV, the majority had symptoms of fever, generalized erythematous rash, and irritability. Fourteen percent had clinical arthritis. Ten percent of patients had seizures. Six percent had meningoencephalitis. There were 2 childhood deaths during the course of this study, one from meningoencephalitis and another from myocarditis. Chikungunya virus can cause severe complications in children, the majority of which impact the central nervous system.

Importance of genetic testing in global health during the evaluation of familial microcephaly.

A focused genetic workup is useful in determining the cause of familial microcephaly, especially in the setting of mildly different phenotypes. As illustrated by this case from an impoverished international urban location, one must not assume the etiology for the apparent familial microcephaly is the same for all affected members.

A novel familial autosomal dominant mutation in ARID1B causing neurodevelopmental delays, short stature, and dysmorphic features.

Recent studies have identified mutations in the ARID1B gene responsible for neurodevelopmental delays, intellectual disability, growth delay, and dysmorphic features. ARID1B encodes a subunit of the BAF chromatin-remodeling complex, and mutations in multiple components of the BAF complex have been implicated as causes of Coffin-Siris syndrome, Nicolaides-Baraitser syndrome, and non-syndromic intellectual disability. The majority of documented pathogenic ARID1B mutations to date have arisen in a sporadic, de novo manner with no reports of inheritance of a pathogenic mutation from an affected parent. We describe here two patients (a 21-year-old female and her 21-month-old son) with a novel frameshift mutation in ARID1B inherited in an autosomal dominant fashion in the affected offspring. Both patients presented with neurodevelopmental delays, growth delay, and dysmorphic features including prominent nose with full nasal tip, long philtrum, and high-arched palate. Exome sequencing analysis in the female patient demonstrated a heterozygous deletion of nucleotide 1259 of the ARID1B gene (c.1259delA) resulting in a frameshift and creation of a premature stop codon. Further family testing by targeted Sanger sequencing confirmed that this arose as a de novo mutation in the mother and was passed on to her affected son. The clinical features of both patients are felt to be consistent with an ARID1B-related disorder. To our knowledge, this is the first report of a pathogenic mutation in ARID1B being passed from an affected parent to their offspring. © 2016 Wiley Periodicals, Inc.

Progressive increase of T1 signal intensity in the dentate nucleus and globus pallidus on unenhanced T1-weighted MR images in the pediatric brain exposed to multiple doses of gadolinium contrast.

Recently, there have been reports of gadolinium accumulation in the brain and bone of adult patients with normal renal function who have undergone multiple gadolinium contrast administrations. This case report gives the first description of a pediatric patient who, following multiple contrasted MRI exams, demonstrated abnormal signal on unenhanced T1-weighted imaging involving the dentate nucleus and globus pallidus, a finding which has previously been shown to represent gadolinium deposition in adults. The patient presented here had no history of intracranial pathology which would alter the blood brain barrier or abnormal renal function. The clinical significance of gadolinium accumulation in the human body is currently unknown but is of concern, particularly in pediatric patients who have a lifetime to manifest any potential adverse consequences. Therefore, research is needed to address the clinical significance, if any, of gadolinium deposition in the developing pediatric brain. Given these current uncertainties, clinicians should continue to use prudence in selecting pediatric patients to undergo contrasted MRI and in selecting the appropriate contrast agents to use.

Redefining the Pediatric Phenotype of X-Linked Monocarboxylate Transporter 8 (MCT8) Deficiency: Implications for Diagnosis and Therapies.

X-linked monocarboxylate transporter 8 (MCT8) deficiency results from a loss-of-function mutation in the monocarboxylate transporter 8 gene, located on chromosome Xq13.2 (Allan-Herndon-Dudley syndrome). Affected boys present early in life with neurodevelopment delays but have pleasant dispositions and commonly have elevated serum triiodothyronine. They also have marked axial hypotonia and quadriparesis but surprisingly little spasticity early in their disease course. They do, however, have subtle involuntary movements, most often dystonia. The combination of hypotonia and dystonia presents a neurorehabilitation challenge and explains why spasticity-directed therapies have commonly produced suboptimal responses. Our aim was to better define the spectrum of motor disability and to elucidate the neuroanatomic basis of the motor impairments seen in MCT8 deficiency using clinical observation and brain magnetic resonance imaging (MRI) in a cohort of 6 affected pediatric patients. Our findings identified potential imaging biomarkers and suggest that rehabilitation efforts targeting dystonia may be more beneficial than those targeting spasticity in the prepubertal pediatric MCT8 deficiency population.

Deletion of 16q24.1 supports a role for the ATP2C2 gene in specific language impairment.

A 10-year-old boy presented with a history of significant delay in language acquisition as well as receptive and expressive language impairment that persisted into elementary school. In school, he exhibited difficulty with reading comprehension, telling and understanding narratives, and making inferences. Other aspects of his neurodevelopment were normal, with no history of significant medical concerns. He did not have hearing impairment, oromotor dysfunction, or specific neurologic abnormalities. He did not meet testing criteria for autism. Chromosomal microarray analysis and quantitative polymerase chain reaction determined that he had a de novo 159-kilobase deletion of chromosome 16q24.1 that included the ATP2C2 gene. ATP2C2 is a known candidate gene for specific language impairment and is postulated to have neurobiological significance in memory-related circuits. Our patient's language deficits were consistent with a global type of specific language impairment impacting language comprehension, formulation, semantics, syntax, and phonology attributed to his de novo chromosome deletion.

Clinical utility of chromosomal microarray analysis in the diagnosis and management of monosomy 7 mosaicism.

There have been dramatic improvements in our ability to more accurately diagnose the underlying genetic causes of developmental delay/intellectual disability; however, there is less known about the treatment trajectory and whether or not patient management and outcomes have changed due to the information gained from genetic testing. Here we report a case study of a 20-month-old male first referred to the genetics clinic in 2008 for interhemispheric cysts, agenesis of the corpus callosum, left cortical dysplasia, and developmental delay of unknown etiology. The diagnostic work-up for this patient included chromosomal microarray which detected >20% mosaicism for monosomy 7, which raised concern for a possible myelodysplastic syndrome. The clone was not detected in stimulated peripheral blood cultures and his karyotype was reported as a normal male. Because of this microarray finding, he was referred to pediatric hematology/oncology where he was confirmed to have a pre-symptomatic diagnosis of myelodysplastic syndrome and was treated with chemotherapy and a bone-marrow transplant. This case illustrates the clinical utility of microarray testing and the importance of long-term follow-up to assess patient outcomes.

Neurodevelopmental delays and macrocephaly in 17p13.1 microduplication syndrome.

Microduplication of chromosome 17p13.1 is a rarely reported chromosome abnormality associated with neurodevelopmental delays. We describe two unrelated patients with overlapping microduplications of chromosome 17p13.1. The first patient is a 2-year-old male who presented with neurodevelopmental delays and macrocephaly. He was found to have a de novo 788 kb copy gain of 17p13.2p13.1 and a de novo 134 kb copy gain of 17p13.1. These duplications include multiple candidate genes, including EFNB3, NLGN2, DLG4, GABARAP, and DULLARD, which may be responsible for neurodevelopmental delays in affected individuals. The second patient is a 29-year-old female with mild intellectual disability and relative macrocephaly. She was found to have a 62.5 kb copy gain of chromosome 17p13.1 that includes the DLG4, GABARAP, and DULLARD genes. The DLG4, GABARAP, and DULLARD genes included in the microduplications of both our patients appear to be candidate genes for neurodevelopmental delays and macrocephaly in individuals with 17p13.1 microduplication syndrome.

Acquired microcephaly in blepharophimosis-ptosis-epicanthus inversus syndrome because of an interstitial 3q22.3q23 deletion.

BACKGROUND: Blepharophimosis-ptosis-epicanthus inversus syndrome is an autosomal dominant condition because of mutations or deletions of the FOXL2 gene. Microcephaly is not associated with FOXL2 mutations but has been reported in individuals with chromosome 3q deletions, which include the FOXL2 gene and other contiguous genes. The ATR gene has been reported as a candidate gene for microcephaly in individuals with contiguous deletion of chromosome 3q involving the FOXL2 gene. PATIENT: We describe a girl with blepharophimosis-ptosis-epicanthus inversus syndrome along with acquired microcephaly and intellectual disability. RESULTS: Our patient had a deletion of chromosome 3q22.2q23, which does not include the ATR gene but does include the PIK3CB gene as a candidate gene for microcephaly. CONCLUSION: We propose that the PIK3CB gene included in our patient's chromosome 3q deletion may be the gene responsible for microcephaly and other patients with blepharophimosis-ptosis-epicanthus inversus syndrome because of a chromosome 3q deletion.

Unique cerebrovascular anomalies in Noonan syndrome with RAF1 mutation.

Noonan syndrome is a common autosomal dominant neurodevelopmental disorder caused by gain-of-function germline mutations affecting components of the Ras-MAPK pathway. The authors present the case of a 6-year-old male with Noonan syndrome, Chiari malformation type I, shunted benign external hydrocephalus in infancy, and unique cerebrovascular changes. A de novo heterozygous change in the RAF1 gene was identified. The patient underwent brain magnetic resonance imaging, computed tomography angiography, and magnetic resonance angiography to further clarify the nature of his abnormal brain vasculature. The authors compared his findings to the few cases of Noonan syndrome reported with cerebrovascular pathology.

ß-Propeller protein-associated neurodegeneration: a new X-linked dominant disorder with brain iron accumulation.

Neurodegenerative disorders with high iron in the basal ganglia encompass an expanding collection of single gene disorders collectively known as neurodegeneration with brain iron accumulation. These disorders can largely be distinguished from one another by their associated clinical and neuroimaging features. The aim of this study was to define the phenotype that is associated with mutations in WDR45, a new causative gene for neurodegeneration with brain iron accumulation located on the X chromosome. The study subjects consisted of WDR45 mutation-positive individuals identified after screening a large international cohort of patients with idiopathic neurodegeneration with brain iron accumulation. Their records were reviewed, including longitudinal clinical, laboratory and imaging data. Twenty-three mutation-positive subjects were identified (20 females). The natural history of their disease was remarkably uniform: global developmental delay in childhood and further regression in early adulthood with progressive dystonia, parkinsonism and dementia. Common early comorbidities included seizures, spasticity and disordered sleep. The symptoms of parkinsonism improved with l-DOPA; however, nearly all patients experienced early motor fluctuations that quickly progressed to disabling dyskinesias, warranting discontinuation of l-DOPA. Brain magnetic resonance imaging showed iron in the substantia nigra and globus pallidus, with a 'halo' of T1 hyperintense signal in the substantia nigra. All patients harboured de novo mutations in WDR45, encoding a beta-propeller protein postulated to play a role in autophagy. Beta-propeller protein-associated neurodegeneration, the only X-linked disorder of neurodegeneration with brain iron accumulation, is associated with de novo mutations in WDR45 and is recognizable by a unique combination of clinical, natural history and neuroimaging features.

Novel mutation in Sjogren-Larsson syndrome is associated with divergent neurologic phenotypes.

Sjögren-Larsson syndrome is an inherited disorder of lipid metabolism caused by mutations in the ALDH3A2 gene that codes for fatty aldehyde dehydrogenase, which results in accumulation of fatty aldehydes and alcohols and is characterized by ichthyosis, intellectual disability, and spastic diplegia/quadriplegia. The authors describe 2 unrelated Honduran patients who carried the same novel homozygous nonsense mutation (c.1309A>T, p.K437X) and ALDH3A2 DNA haplotype, but widely differed in disease severity. One patient exhibited spastic quadriplegia with unusual neuroregression, whereas the other patient had the usual static form of spastic diplegia with neurodevelopmental disabilities. Biochemical analyses showed a similar profound deficiency of fatty aldehyde dehydrogenase activity and impaired fatty alcohol metabolism in both patients' cultured fibroblasts. These results indicate that variation in the neurologic phenotype of Sjögren-Larsson syndrome is not strictly determined by the ALDH3A2 mutation or the biochemical defect as expressed in cultured fibroblasts, but by unidentified epigenetic/environmental factors, gene modifiers, or other mechanisms.

Unbalanced translocation involving partial trisomy 9p and partial monosomy yq with neurodevelopmental delays.

We present a 4-year-old Honduran boy with mild neurodevelopmental delays, growth delays, dysmorphic features, and small genitalia. Chromosome analysis initially revealed a single X chromosome and a marker chromosome derived from the short arm of chromosome 9 which was consistent with Turner syndrome as only 1 sex chromosome could be identified. However, on further analysis, he was found to have an unbalanced translocation involving the short arm of chromosome 9 and the long arm of the Y chromosome. The translocation resulted in partial trisomy 9p and partial monosomy Yq. The patient's clinical features are felt to be the result of partial trisomy 9p. In addition, partial monosomy Yq is associated with male infertility. Testing of the patient's parents was normal, indicating this was a de novo translocation. Additional evaluations of this child and his parents allowed an accurate assessment of his diagnosis, long-term prognosis, and chance of recurrence.

Neuroscience curriculum changes and outcomes: medical university of South Carolina, 2006 to 2010.

OBJECTIVES: To develop future neurologists and translational neuroscientists, we created a neurosciences pathway throughout our medical school curriculum that included early exposure to clinical neurosciences decision-making and added variety to the choices of later clinical neurosciences experiences. METHODS: Our curricular innovation had 3 parts: (1) integrating basic neurosciences content into an explicit clinical context in a College of Medicine (COM) first year of medical school; (2) expanding pathophysiological principles related to neurosciences in COM second year of medical school; and (3) creating a variety of 3-week clinical neurosciences selectives in COM third year of medical school and 4-week electives/externships for interested learners in COM fourth year of medical school. These new changes were evaluated (1) by comparing national standardized examinations including Neurology Subject examination scores for students choosing clinical neurosciences selectives; (2) by student satisfaction Graduate Questionnaires; and (3) by the total number of our graduates matching in US neurosciences disciplines. RESULTS: Students taking neuroscience selectives demonstrated a nonsignificant trend toward higher Step 2 Clinical Knowledge scores. The students' Neurology Subject examination scores were comparable with those scores reported nationally for other US COM third year of medical school students on 4-week rotations. Student-reported satisfaction in clinical neurology teaching improved from 43.9% (before) to 81.8% (after). The percentage of students matching into clinical neuroscience disciplines rose from 2% (before) to 6% (after). CONCLUSIONS: Our neurosciences curricular innovation increased graduating student satisfaction scores, had a mild positive impact on Step 2 Clinical Knowledge scores, and increased the number of students choosing careers in the clinical neurosciences. This model may be a consideration for other medical schools who wish to integrate neurosciences teaching throughout their curriculum.

Seizures and X-linked intellectual disability.

Intellectual disability occurs as an isolated X-linked trait and as a component of recognizable X-linked syndromes in the company of somatic, metabolic, neuromuscular, or behavioral abnormalities. Seizures accompany intellectual disability in almost half of these X-linked disorders. The spectrum of seizures found in the X-linked intellectual disability syndromes is broad, varying in time of onset, type of seizure, and response to anticonvulsant therapy. The majority of the genes associated with XLID and seizures have now been identified.