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The COL4A1 (collagen Type 4 alpha1) pathogenic variant is associated with porencephaly and schizencephaly and accounts for approximately 20% of these patients. This gene variant leads to systemic microvasculopathy, which manifests as brain, ocular, renal, and muscular disorders. However, only a few patients with surgical interventions have been reported and the potential surgical risks are unknown. Here, we present the cases of two female patients between 7 and 8 years of age who were diagnosed with the COL4A1 variant and underwent laparoscopy-assisted percutaneous endoscopic gastrostomy (LAPEG) for oral dysphagia. Their primary brain lesions were caused by porencephaly and paralysis, which are caused by multiple cerebral hemorrhages and infarctions, and both patients had refractory epileptic complications. Although LAPEG was successfully performed in both patients without any intraoperative complications, one patient developed alveolar hemorrhage postoperatively and required mechanical ventilation. Thus, careful perioperative management of patients with the COL4A1 variant is important.
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Laparoscopía , Porencefalia , Esquizencefalia , Humanos , Femenino , Gastrostomía/efectos adversos , Esquizencefalia/genética , Laparoscopía/efectos adversos , Complicaciones Intraoperatorias , Colágeno Tipo IV/genéticaRESUMEN
Successful surgery for drug-resistant pediatric epilepsy can facilitate motor and cognitive development and improve quality of life by resolution or reduction of epileptic seizures. Therefore, surgery should be considered early in the disease course. However, in some cases, the estimated surgical outcomes are not achieved, and additional surgical treatments are considered. In this study, we investigated the clinical factors related with such unsatisfactory outcomes.We reviewed the clinical data of 92 patients who underwent 112 surgical procedures (69 resection and 53 palliation procedures). Surgical outcomes were assessed according to the postoperative disease status, which was classified as good, controlled, and poor. The following clinical factors were analyzed in relation to surgical outcome: sex, age at onset, etiology (malformation of cortical development, tumor, temporal lobe epilepsy, scar, inflammation, and non-lesional epilepsy), presence of genetic cause, and history of developmental epileptic encephalopathy. At a median of 59 (30-81.25) months after the initial surgery, the disease status was good in 38 (41%), controlled in 39 (42%), and poor in 15 (16%) patients. Among the evaluated factors, etiology exhibited the strongest correlation with surgical outcomes. Tumor-induced and temporal lobe epilepsy were correlated with good, whereas malformation of cortical development, early seizure onset, and presence of genetic cause were correlated with poor disease status. Although epilepsy surgery for the patients who present with the latter factors is challenging, these patients demonstrate a greater need for surgical treatment. Hence, development of more effective surgical options is warranted, including palliative procedures.
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Epilepsia Refractaria , Epilepsia del Lóbulo Temporal , Epilepsia , Niño , Humanos , Epilepsia del Lóbulo Temporal/cirugía , Calidad de Vida , Resultado del Tratamiento , Epilepsia/cirugía , Convulsiones , Epilepsia Refractaria/cirugía , Electroencefalografía , Estudios RetrospectivosRESUMEN
OBJECTIVE: In glucose transporter 1 deficiency syndrome (Glut1DS), cerebrospinal fluid glucose (CSFG) and CSFG to blood glucose ratio (CBGR) show significant differences among groups classified by phenotype or genotype. The purpose of this study was to investigate the association between these biochemical parameters and Glut1DS severity. METHODS: The medical records of 45 patients who visited Osaka University Hospital between March 2004 and December 2021 were retrospectively examined. Neurological status was determined using the developmental quotient (DQ), assessed using the Kyoto Scale of Psychological Development 2001, and the Scale for the Assessment and Rating of Ataxia (SARA). CSF parameters included CSFG, CBGR, and CSF lactate (CSFL). RESULTS: CSF was collected from 41 patients, and DQ and SARA were assessed in 24 and 27 patients, respectively. Simple regression analysis showed moderate associations between neurological status and biochemical parameters. CSFG resulted in a higher R2 than CBGR in these analyses. CSF parameters acquired during the first year of life were not comparable to those acquired later. CSFL was measured in 16 patients (DQ and SARA in 11 and 14 patients, respectively). Although simple regression analysis also showed moderate associations between neurological status and CSFG and CSFL, the multiple regression analysis for DQ and SARA resulted in strong associations through the use of a combination of CSFG and CSFL as explanatory variables. CONCLUSION: The severity of Glut1DS can be predicted from CSF parameters. Glucose and lactate are independent contributors to the developmental and neurological status in Glut1DS.
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Glucemia , Glucosa , Estudios Retrospectivos , Transportador de Glucosa de Tipo 1/genética , Glucosa/líquido cefalorraquídeo , Ácido Láctico , Líquido CefalorraquídeoRESUMEN
In the field of hereditary spastic paraplegia (HSP), progress in molecular diagnostics needs to be translated into robust phenotyping studies to understand genetic and phenotypic heterogeneity and to support interventional trials. ZFYVE26-associated hereditary spastic paraplegia (HSP-ZFYVE26, SPG15) is a rare, early-onset complex HSP, characterized by progressive spasticity and a variety of other neurological symptoms. While prior reports, often in populations with high rates of consanguinity, have established a general phenotype, there is a lack of systematic investigations and a limited understanding of age-dependent manifestation of symptoms. Here we delineate the clinical, neuroimaging and molecular features of 44 individuals from 36 families, the largest cohort assembled to date. Median age at last follow-up was 23.8 years covering a wide age range (11-61 years). While symptom onset often occurred in early childhood [median: 24 months, interquartile range (IQR) = 24], a molecular diagnosis was reached at a median age of 18.8 years (IQR = 8), indicating significant diagnostic delay. We demonstrate that most patients present with motor and/or speech delay or learning disabilities. Importantly, these developmental symptoms preceded the onset of motor symptoms by several years. Progressive spasticity in the lower extremities, the hallmark feature of HSP-ZFYVE26, typically presents in adolescence and involves the distal lower limbs before progressing proximally. Spasticity in the upper extremities was seen in 64%. We found a high prevalence of extrapyramidal movement disorders including cerebellar ataxia (64%) and dystonia (11%). Parkinsonism (16%) was present in a subset and showed no sustained response to levodopa. Cognitive decline and neurogenic bladder dysfunction progressed over time in most patients. A systematic analysis of brain MRI features revealed a common diagnostic signature consisting of thinning of the anterior corpus callosum, signal changes of the anterior forceps and non-specific cortical and cerebellar atrophy. The molecular spectrum included 45 distinct variants, distributed across the protein structure without mutational hotspots. Spastic Paraplegia Rating Scale scores, SPATAX Disability Scores and the Four Stage Functional Mobility Score showed moderate strength in representing the proportion of variation between disease duration and motor dysfunction. Plasma neurofilament light chain levels were significantly elevated in all patients (Mann-Whitney U-test, P < 0.0001) and were correlated inversely with age (Spearman's rank correlation coefficient r = -0.65, P = 0.01). In summary, our systematic cross-sectional analysis of HSP-ZFYVE26 patients across a wide age-range, delineates core clinical, neuroimaging and molecular features and identifies markers of disease severity. These results raise awareness to this rare disease, facilitate an early diagnosis and create clinical trial readiness.
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Paraplejía Espástica Hereditaria , Humanos , Preescolar , Paraplejía Espástica Hereditaria/genética , Estudios Transversales , Diagnóstico Tardío , Proteínas/genética , MutaciónRESUMEN
BACKGROUND AND OBJECTIVES: Neuroinflammation contributes to the severity of various neurological disorders, including epilepsy. Tuberous sclerosis complex (TSC) is a condition that results in the overactivation of the mammalian target of rapamycin (mTOR) pathway, which has been linked to the activation of microglia responsible for neuroinflammation. To clarify the involvement of neuroinflammation in the neuropathophysiology of TSC, we performed a positron emission tomography (PET) study using the translocator protein (TSPO) radioligand, [11C] DPA713, and investigated microglial activation in relation to neurological manifestations, especially epilepsy and cognitive function. METHODS: This cross-sectional study included 18 patients with TSC (6 in the no-seizure group, 6 in the refractory seizure group, and 6 in the mTOR-inhibitor [mTOR-i] group). All participants underwent [11C] DPA713-PET. PET results were superimposed with a 3D T2-weighted fluid-attenuated inversion-recovery (FLAIR) and T1-weighted image (T1WI) to evaluate the location of cortical tubers. Microglial activation was assessed using the standardized uptake value ratio (SUVr) of DPA713 binding. The volume ratio of the DPA713-positive area to the intracranial volume (volume ratio of DPA713/ICV) was calculated to evaluate the extent of microglial activation. A correlation analysis was performed to examine the relationship between volume ratio of DPA713/ICV and severity of epilepsy and cognitive function. RESULTS: Most cortical tubers with hyperintensity on FLAIR and hypo- or isointensity on T1WI showed microglial activation. The extent of microglial activation was significantly greater in the refractory seizure group than in the no-seizure or mTOR-i groups (p < 0.001). The extent of microglial activation in subjects without mTOR-i treatment correlated positively with epilepsy severity (r = 0.822, P = 0.001) and negatively with cognitive function (r = -0.846, p = 0.001), but these correlations were not present in the mTOR-i group (r = 0.232, P = 0.658, r = 0.371, P = 0.469, respectively). CONCLUSION: Neuroinflammation is associated with the severity of epilepsy and cognitive dysfunction in brains with TSC. mTOR-i may suppress the extent of neuroinflammation in TSC. Investigating the spread of microglial activation using TSPO-PET in these patients may help to predict the progression of neuropathy by assessing the degree of neuroinflammation and therefore be useful for determining how aggressive the treatment should be and in assessing the effectiveness of such treatment in patients with TSC.
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Disfunción Cognitiva , Epilepsia , Esclerosis Tuberosa , Humanos , Microglía , Enfermedades Neuroinflamatorias , Esclerosis Tuberosa/complicaciones , Esclerosis Tuberosa/diagnóstico por imagen , Esclerosis Tuberosa/metabolismo , Estudios Transversales , Tomografía Computarizada por Rayos X , Epilepsia/etiología , Epilepsia/complicaciones , Tomografía de Emisión de Positrones/métodos , Convulsiones/complicaciones , Disfunción Cognitiva/etiología , Disfunción Cognitiva/complicaciones , Serina-Treonina Quinasas TOR/metabolismo , Receptores de GABA/metabolismoRESUMEN
Inherited glycosylphosphatidylinositol (GPI) deficiency (IGD) is caused by mutations in GPI biosynthesis genes. The mechanisms of its systemic, especially neurological, symptoms are not clarified and fundamental therapy has not been established. Here, we report establishment of mouse models of IGD caused by PIGO mutations as well as development of effective gene therapy. As the clinical manifestations of IGD are systemic and lifelong lasting, we treated the mice with adeno-associated virus for homology-independent knock-in as well as extra-chromosomal expression of Pigo cDNA. Significant amelioration of neuronal phenotypes and growth defect was achieved, opening a new avenue for curing IGDs.
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Glicosilfosfatidilinositoles , Convulsiones , Animales , Modelos Animales de Enfermedad , Terapia Genética , Glicosilfosfatidilinositoles/deficiencia , Glicosilfosfatidilinositoles/genética , Inmunoglobulina D/genética , Ratones , Convulsiones/genéticaRESUMEN
BACKGROUND: Of the patients with glucose transporter 1 deficiency syndrome (GLUT1-DS), 90% have a pathologic gait. Ataxic-spastic and ataxic gaits are seen in 35% of patients each. A ketogenic diet and modified Atkins diet (MAD) are effective therapy in GLUT1-DS in terms of both the seizures and movement disorder. A three-dimensional gait analysis (3DGA) system can be used to evaluate gait quantitatively using spatiotemporal data and gait kinematics. We performed 3DGA in three ambulatory patients with GLUT1-DS to evaluate the characteristics of their gait pathology, and we compared the gait variables before and after enhancing the MAD in one patient. METHODS: After examination by pediatric neurologists and pediatric orthopedic surgeons, 3DGA was performed. We assessed walking speed, step length, step width, gait variability, Gait Deviation Index (GDI), Gait Profile Score (GPS), and Gait Variable Score (GVS). RESULTS: All three patients had a low GDI and high GPS, comprehensive indices of gait pathology. The unstable gait pattern featured a wide step width in one patient and high gait variability in two patients. In the sagittal plane, the patients had increased GVSs in the knee and ankle joints due to excessive knee flexion or extension and excessive ankle plantarflexion. In the horizontal plane, the patients had increased GVSs in the pelvis, hips, and foot due to excessive rotation during walking. After enhancing the MAD, GDI, GPS, and GVSs improved. CONCLUSIONS: 3DGA has potential for quantifying the characteristics of gait pathology and its improvement with dietary therapy in patients with GLUT1-DS.
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Errores Innatos del Metabolismo de los Carbohidratos , Trastornos del Movimiento , Errores Innatos del Metabolismo de los Carbohidratos/diagnóstico , Niño , Marcha , Transportador de Glucosa de Tipo 1 , Humanos , Proteínas de Transporte de Monosacáridos/deficiencia , CaminataRESUMEN
BACKGROUND: Arthrogryposis, renal dysfunction, and cholestasis syndrome (ARCS) is a rare autosomal recessive disorder caused by mutations in VPS33B (ARCS1) and VIPAS39 (ARCS2). As per literature, most patients with ARCS died of persistent infections and bleeding by the age of 1 year. We report the first Japanese cases with ARCS1 and ARCS2 who presented with mild phenotypes and were diagnosed via genetic testing. CASE PRESENTATION: Case 1: A 6-year-old boy born to nonconsanguineous Japanese parents presented with jaundice and normal serum gamma-glutamyl transferase (GGT) levels, proteinuria, bilateral nerve deafness, motor delay, failure to thrive, and persistent pruritus. After cochlear implantation for deafness at the age of 2 years, despite a normal platelet count and prothrombin time-international normalized ratio, the patient presented with persistent bleeding that required hematoma removal. Although he did not show any obvious signs of arthrogryposis, he was suspected to have ARCS based on other symptoms. Compound heterozygous mutations in VPS33B were identified using targeted next-generation sequencing (NGS), which resulted in no protein expression. Case 2: A 7-month-old boy, the younger brother of case 1, presented with bilateral deafness, renal tubular dysfunction, failure to thrive, and mild cholestasis. He had the same mutations that were identified in his brother's VPS33B. Case 3: A 24-year-old man born to nonconsanguineous Japanese parents was suspected to have progressive familial intrahepatic cholestasis 1 (PFIC1) in his childhood on the basis of low GGT cholestasis, renal tubular dysfunction, sensory deafness, mental retardation, and persistent itching. A liver biopsy performed at the age of 16 years showed findings that were consistent with PFIC1. He developed anemia owing to intraperitoneal hemorrhage from a peripheral intrahepatic artery the day after the biopsy, and transcatheter arterial embolization was required. ARCS2 was diagnosed using targeted NGS, which identified novel compound heterozygous mutations in VIPAS39. CONCLUSIONS: The first Japanese cases of ARCS1 and ARCS2 diagnosed using genetic tests were reported in this study. These cases are milder than those previously reported. For patients with ARCS, invasive procedures should be performed with meticulous care to prevent bleeding.
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Artrogriposis , Colestasis , Adolescente , Adulto , Artrogriposis/diagnóstico , Artrogriposis/genética , Niño , Preescolar , Colestasis/genética , Humanos , Lactante , Japón , Masculino , Mutación , Fenotipo , Insuficiencia Renal , Proteínas de Transporte Vesicular/genética , Adulto JovenRESUMEN
OBJECTIVE: To examine the current medical and psychosocial status of patients with epilepsy, aiming to facilitate appropriate application of the Intractable/Rare Diseases Act of Japan. METHODS: By analysing the cross-sectional data of patients registered in the tertiary hospital-based Epilepsy Syndrome Registry of Japan, we investigated the proportion of patients who met the severity criteria as defined by the Act (seizure frequency of at least once a month, or presence of intellectual/neurological/psychiatric symptoms, or both) and whether there are candidate syndrome/diseases to be added to the existing list in the Act. RESULTS: In total, 2,209 patients were registered. After excluding self-limited/idiopathic epilepsies, 1,851 of 2,110 patients (87.7%) met the severity criteria. The patients were classified into eight main epilepsy syndromes (594 patients), 20 groups based on aetiology (1,078 patients), and three groups without known aetiology (427 patients). Most of the groups classified by syndrome or aetiology had high proportions of patients satisfying the severity criteria (>90%), but some groups had relatively low proportions (<80%) resulting from favourable outcome of surgical therapy. Several small groups with known syndrome/aetiology await detailed analysis based on a sufficiently large enough number of patients registered, some of whom may potentially be added to the list of the Act. SIGNIFICANCE: The registry provides data to examine the usefulness of the severity criteria and list of diseases that are operationally defined by the Act. Most epilepsy patients with various syndromes/diseases and aetiology groups are covered by the Act but some are not, and the list of designated syndromes/diseases should be complemented by further amendments, as suggested by future research.
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Epilepsia , Convulsiones , Comorbilidad , Estudios Transversales , Epilepsia/epidemiología , Síndromes Epilépticos , Encuestas Epidemiológicas , Humanos , Japón/epidemiología , Sistema de Registros , Convulsiones/epidemiología , Centros de Atención TerciariaRESUMEN
Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder that causes degeneration of anterior horn cells in the human spinal cord and subsequent loss of motor neurons. The severe form of SMA is among the genetic diseases with the highest infant mortality. Although SMA has been considered incurable, newly developed drugs-nusinersen and onasemnogene abeparvovec-improve the life prognoses and motor functions of affected infants. To maximize the efficacy of these drugs, treatments should be started at the pre-symptomatic stage of SMA. Thus, newborn screening for SMA is now strongly recommended. Herein, we provide some data based on our experience of SMA diagnosis by genetic testing in Japan. A total of 515 patients suspected of having SMA or another lower motor neuron disease were tested. Among these patients, 228 were diagnosed as having SMA with survival motor neuron 1 (SMN1) deletion. We analyzed the distribution of clinical subtypes and ages at genetic testing in the SMN1-deleted patients, and estimated the SMA incidence based on data from Osaka and Hyogo prefectures, Japan. Our data showed that confirmed diagnosis by genetic testing was notably delayed, and the estimated incidence was 1 in 30,000-40,000 live births, which seemed notably lower than in other countries. These findings suggest that many diagnosis-delayed or undiagnosed cases may be present in Japan. To prevent this, newborn screening programs for SMA (SMA-NBS) need to be implemented in all Japanese prefectures. In this article, we also introduce our pilot study for SMA-NBS in Osaka Prefecture.
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OBJECTIVE: To unveil current medical and psychosocial conditions of patients with West syndrome in Japan. METHODS: A cross-sectional analysis was performed in patients with West syndrome registered in the Rare Epilepsy Syndrome Registry (RES-R) of Japan. Furthermore, new-onset patients registered in the RES-R were observed prospectively and their outcomes after one and two years of follow-up were compared with data at onset. RESULTS: For the cross-sectional study, 303 patients with West syndrome were included. Seizures (such as spasms, tonic seizures and focal seizures) occurred daily in 69.3% of the patients at registration. Seizure frequency of less than one per year was observed in cases of unknown etiology (22.6%), genetic etiology (23.8%) and malformation of cortical development (MCD; 19.1%). Neurological findings were absent in 37.0%, but a high rate of abnormality was seen in patients with Aicardi syndrome, hypoxic-ischemic encephalopathy (HIE), genetic etiology and MCD other than focal cortical dysplasia, accompanied by a >50% rate of bedridden patients. Abnormal EEG was found in 96.7%, and CT/MRI was abnormal in 62.7%. Treatments included antiepileptic drug therapy (94.3%), hormonal therapy (72.6%), diet therapy (8.3%) and surgery (15.8%). Intellectual/developmental delay was present in 88.4%, and was more severe in patients with Aicardi syndrome, genetic etiology and HIE. Autism spectrum disorder was found in 13.5%. For the longitudinal study, 27 new-onset West syndrome patients were included. The follow-up study revealed improved seizure status after two years in 66.7%, but worsened developmental status in 55.6%, with overall improvement in 51.9%. SIGNIFICANCE: The study reveals the challenging neurological, physical and developmental aspects, as well as intractable seizures, in patients with West syndrome. More than a half of the children showed developmental delay after onset, even though seizures were reduced during the course of the disease.
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Espasmos Infantiles , Síndrome de Aicardi , Trastorno del Espectro Autista/epidemiología , Niño , Estudios Transversales , Electroencefalografía , Estudios de Seguimiento , Humanos , Hipoxia-Isquemia Encefálica , Lactante , Japón/epidemiología , Estudios Longitudinales , Convulsiones , Condiciones Sociales , Espasmos Infantiles/epidemiologíaRESUMEN
BACKGROUND: Familial hemiplegic migraine (FHM) is an inherited autosomal dominant disorder characterized by migraine with reversible hemiplegia. FHM1 is caused by variants in CACNA1A, encoding a P/Q type neuronal voltage-gated calcium channel α subunit, which is also associated with episodic ataxia type 2 (EA2). FHM2 is associated with ATP1A2, which codes for an Na+/K+-ATPase isoform 2 subunit. CASE PRESENTATION: We identified an FHM2 family, the mother and her daughter, with a novel variant in ATP1A2, p.Gly377Asp, located in a well-conserved P-type ATPase motif. Additionally, the mother harbored deletion in the CACNA1A, associated with EA2, but her daughter did not. The mother presented migraine with typical aura without motor deficit, whereas her daughter had migraine accompanied by recurrent motor deficit and altered consciousness. The additional CACNA1A deletion in the mother might serve as a modifier. CONCLUSION: Our report emphasizes the importance of genetic analysis to diagnose neurological ion channel/transporter diseases.
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Canales de Calcio/genética , ATPasa Intercambiadora de Sodio-Potasio/genética , Secuencias de Aminoácidos , Femenino , Pruebas Genéticas , Humanos , Persona de Mediana Edad , Migraña con Aura/diagnóstico , Migraña con Aura/genética , ATPasas Tipo P/química , Linaje , ATPasa Intercambiadora de Sodio-Potasio/químicaRESUMEN
OBJECTIVE: We aimed to assess the efficacy and safety of high-dose pyridoxine treatment for seizures and its effects on development in patients with inherited glycosylphosphatidylinositol deficiencies (IGDs). METHODS: In this prospective open-label multicenter pilot study, we enrolled patients diagnosed with IGDs using flow cytometry and/or genetic tests. The patients received oral pyridoxine (20-30 mg/kg/day) for 1 year, in addition to previous treatment. RESULTS: All nine enrolled patients (mean age: 66.3 ± 44.3 months) exhibited marked decreases in levels of CD16, a glycosylphosphatidylinositol-anchored protein, on blood granulocytes. The underlying genetic causes of IGDs were PIGO, PIGL, and unknown gene mutations in two, two, and five patients, respectively. Six patients experienced seizures, while all patients presented with developmental delay (mean developmental age: 11.1 ± 8.1 months). Seizure frequencies were markedly (>50%) and drastically (>90%) reduced in three and one patients who experienced seizures, respectively. None of the patients presented with seizure exacerbation. Eight of nine patients exhibited modest improvements in development (P = 0.14). No adverse events were observed except for mild transient diarrhea in one patient. CONCLUSION: One year of daily high-dose pyridoxine treatment was effective in the treatment of seizures in more than half of our patients with IGDs and modestly improved development in the majority of them. Moreover, such treatment was reasonably safe. These findings indicate that high-dose pyridoxine treatment may be effective against seizures in patients with IGDs, although further studies are required to confirm our findings. (University Hospital Medical Information Network Clinical Trials Registry [UMIN-CTR] number: UMIN000024185.).
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Glicosilfosfatidilinositoles/deficiencia , Piridoxina/farmacología , Convulsiones/tratamiento farmacológico , Complejo Vitamínico B/farmacología , Adolescente , Niño , Preescolar , Femenino , Glicosilfosfatidilinositoles/genética , Humanos , Lactante , Masculino , Evaluación de Resultado en la Atención de Salud , Proyectos Piloto , Estudios Prospectivos , Piridoxina/administración & dosificación , Convulsiones/complicaciones , Convulsiones/etiología , Convulsiones/genética , Complejo Vitamínico B/administración & dosificaciónRESUMEN
Pyruvate dehydrogenase complex (PDHC) deficiency is a mitochondrial disorder. We report two cases of PDHC deficiency with clinical symptoms and brain imaging findings reminiscent of FOXG1 syndrome, suggesting a phenotypic overlap of these disorders.
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This study aimed to elucidate the clinical characteristics of MECP2 duplication syndrome (MDS), particularly at initial presentation, and to provide clinical clues for the early diagnosis of this condition. We conducted a nationwide survey for MDS by sending questionnaires to 575 hospitals where board-certified pediatric neurologists were working and 195 residential hospitals for persons with severe motor and intellectual disabilities in Japan. This survey found 65 cases of MDS, and clinical data of 24 cases in which the diagnosis was genetically confirmed were analyzed. More than half of the patients (52%) had visited a hospital at least once during infancy due to symptoms associated with MDS, with a median age at the initial visit of 7 months. The symptoms that were frequently prevalent at the first visit were facial dysmorphic features, hypotonia, motor developmental delay, and recurrent infections. Dysmorphic features included small mouth, tented upper lip, tapered fingers, and hypertelorism. Other symptoms, including epilepsy, intellectual disabilities, autistic features, stereotypic movements, and gastrointestinal problems, generally appeared later with age. Some symptoms of MDS were found to be age-dependent and may not be noticeable in infancy. Recognition of these clinical characteristics may facilitate the early diagnosis and proper treatment of patients with MDS, improve their long-term outcomes, and help adapt appropriate genetic counseling.