Role of TRAK1 variants in epilepsy: genotype-phenotype analysis in a pediatric case of epilepsy with developmental disorder.

Purpose: The TRAK1 gene is mapped to chromosome 3p22.1 and encodes trafficking protein kinesin binding 1. The aim of this study was to investigate the genotype-phenotype of TRAK1-associated epilepsy. Methods: Trio-based whole-exome sequencing was performed on a cohort of 98 patients with epilepsy of unknown etiologies. Protein modeling and the VarCards database were used to predict the damaging effects of the variants. Detailed neurological phenotypes of all patients with epilepsy having TRAK1 variants were analyzed to assess the genotype-phenotype correlations. Results: A novel TRAK1 compound heterozygous variant comprising variant c.835C > T, p.Arg279Cys and variant c.2560A > C, p.Lys854Gln was identified in one pediatric patient. Protein modeling and VarCards database analyses revealed that the variants were damaging. The patient received a diagnosis of early infantile epileptic spasms with a developmental disorder; he became seizure-free through valproate and adrenocorticotropic hormone treatment. Further results for six variants in 12 patients with epilepsy indicated that biallelic TRAK1 variants (including homozygous or compound heterozygous variants) were associated with epilepsy with developmental disorders. Among these patients, eight (67%) had epileptic spasms and seven (58%) were intractable to anti-seizure medicines. Moreover, eight patients experienced refractory status epilepticus, of which seven (88%) died in early life. To our knowledge, this is the first reported case of epilepsy caused by TRAK1 compound heterozygous variants. Conclusion: Biallelic TRAK1 variants can cause epilepsy and developmental disorders. In these patients, seizures progress to status epilepticus, suggesting a high risk for poor outcomes and the requirement of early treatment.

Investigation of FRMPD4 variants associated with X-linked epilepsy.

BACKGROUND: The etiology of unexplained epilepsy in most patients remains unclear. Variants of FRMPD4 are suggested to be associated with neurodevelopmental disorders. Therefore, we screened for disease-causing FRMPD4 variants in patients with epilepsy. METHODS: Trios-based whole-exome sequencing was conducted on a cohort of 85 patients with unexplained epilepsy, their parents, and extended family members. Additional cases with FRMPD4 variants were identified from the China Epilepsy Gene Matching Platform V.1.0. The frequency of variants was analyzed, and their subregional effects were predicted using in silico tools. The genotype-phenotype correlation of the newly defined causative genes and protein stability were analyzed using I-Mutant V.3.0 and Grantham scores. RESULTS: Two novel missense variants of FRMPD4 were identified in two families. Using the gene matching platform, we identified three additional novel missense variants. These variants presented at low or no allele frequencies in the gnomAD database. All the variants were located outside the three FRMPD4 main domains (WW, PDZ, and FERM). In silico analyses revealed that the variants were damaging and were predicted to be the least stable. All patients eventually became seizure-free. Eight of the 21 patients with FRMPD4 variants had epilepsy, of which five (63%) had missense variants located outside the domains, two had deletions involving exon 2, and one had a frameshift variant located outside the domains. Patients with epilepsy caused by missense variants were often free of intellectual disabilities (4/5), whereas patients with epilepsy caused by truncated variants had intellectual disabilities and structural brain abnormalities (3/3). CONCLUSIONS: The FRMPD4 gene is potentially associated with epilepsy. The genotype-phenotype correlation of FRMPD4 variants indicated that differences in variant types and locations of FRMPD4 may explain their phenotypic variation.

CD40LG-associated X-linked Hyper-IgM Syndrome (XHIGM) with pulmonary alveolar proteinosis: a case report.

BACKGROUND: D40LG-associated X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis has rarely been reported, and its genotype-phenotypic correlation remains elusive. CASE PRESENTATION: We describe a five-month-old boy with CD40LG mutation (c.516T > A, p.Tyr172Ter) X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis as the first manifestation. The patient completely recovered after immunotherapy and allogeneic hematopoietic stem cell transplantation. In addition, four previously reported patients with CD40LG mutation with pulmonary alveolar proteinosis were also analyzed. All of these patients presented with early onset of pulmonary infections and a good response to immunotherapy. The structural model of CD40LG indicated that all mutations caused the X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis to be located within the tumor necrosis factor homology domain. CONCLUSIONS: A case was presented, and the characteristics of four cases of CD40LG-associated X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis were summarized. The variant locations may explain the phenotypic heterogeneity of patients with the CD40LG mutation.

The increase of Nrf2 m6A modification induced by FTO downregulation promotes hippocampal neuron injury and aggravates the progression of epilepsy in a rat model.

Epilepsy is a common chronic neurological disorder characterized by widespread neuronal death. The purpose of this study was to investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) m6A methylation in epilepsy. To create epileptic models, the rats were given Lithium chloride and pilocarpine, and isolated primary rat hippocampal neurons were cultured in an Mg2+ -free medium. The frequency of seizures was recorded in the epilepsy group of rats. The functional tests included TUNEL, MTT, and flow cytometry. Mechanistically, RNA degradation assay, RNA immunoprecipitation, and methylated RNA immunoprecipitation were performed. In epileptic models, Nrf2 and fat mass and obesity-associated (FTO) levels were downregulated, whereas YT521-B homology (YTH) domain family protein 2 (YTHDF2) was upregulated. Additionally, in epileptic models, there was a rise in the m6A methylation level of Nrf2 mRNA. Overexpressing FTO increased cell viability and reduced apoptosis, but Nrf2 interference reversed these effects. Meanwhile, FTO overexpression decreased the m6A methylation of Nrf2 mRNA. Moreover, YTHDF2 bound to Nrf2 mRNA and decreased its stability. Furthermore, FTO overexpression reduced seizure frequency in rats and inhibited hippocampal neuron apoptosis via lowering the m6A methylation level of Nrf2 mRNA. Overexpressing FTO reduced m6A methylation of Nrf2 mRNA, increased cell viability, suppressed apoptosis, and slowed the progression of epileptic diseases, which is linked to YTHDF2 binding to m6A-modified Nrf2 and promoting its degradation, as well as downregulating Nrf2 expression in hippocampal neurons.

Phenotypic expansion of KCNH1-associated disorders to include isolated epilepsy and its associations with genotypes and molecular sub-regional locations.

PURPOSE: Genotype-phenotypic correlation of KCNH1 variant remains elusive. This study aimed to expand the phenotypic spectrum of KCNH1 and explore the correlations between epilepsy and molecular sub-regional locations. METHODS: We performed whole-exome sequencing in a cohort of 98 patients with familiar febrile seizure (FS) or epilepsy with unexplained etiologies. The damaging effects of variants were predicted by protein modeling and multiple in silico tools. All reported patients with KCNH1 pathogenic variants with detailed neurological phenotypes were analyzed to evaluate the genotype-phenotype correlation. RESULTS: Two novel KCNH1 variants were identified in three cases, including two patients with FS with inherited variant (p.Ile113Thr) and one boy with epilepsy with de novo variant (p.Arg357Trp). Variant Ile113Thr was located within the eag domain, and variant p.Arg357Trp was located in transmembrane domain 4 of KCNH1, respectively. Two patients experienced refractory status epilepticus (SE), of which one patient died of acute encephalopathy induced by SE. Further analysis of 30 variants in 51 patients demonstrated that de novo variants were associated with epileptic encephalopathy, while mosaic/somatic or germline variants cause isolated epilepsy/FS. All hotspot variants associated with epileptic encephalopathy clustered in transmembrane domain (S4 and S6), while those with isolated epilepsy/seizures or TBS/ZLS without epilepsy were scattered in the KCNH1. CONCLUSIONS: We found two novel missense variants of KCNH1 in three individuals with isolated FS/epilepsy. Variants in the KCNH1 cause a spectrum of epileptic disorders ranging from a benign form of genetic isolated epilepsy/FS to intractable form of epileptic encephalopathy. The genotypes and variant locations help explaining the phenotypic variation of patients with KCNH1 variant.

Variants in BRWD3 associated with X-linked partial epilepsy without intellectual disability.

AIMS: Etiology of the majority patients with idiopathic partial epilepsy (IPE) remains elusive. We thus screened the potential disease-associated variants in the patients with IPE. METHODS: Trios-based whole exome sequencing was performed in a cohort of 320 patients with IPE. Frequency and molecular effects of variants were predicted. RESULTS: Three novel BRWD3 variants were identified in five unrelated cases with IPE, which were four male cases and one female case. The variants included two recurrent missense variants (c.836C>T/p.Thr279Ile and c.4234A>C/p.Ile1412Leu) and one intronic variant close to splice site (c.2475 + 6A>G). The two missense variants were located in WD40 repeat domain and bromodomain, respectively. They were predicted to be damaging by silico tools and change hydrogen bonds with surrounding amino acids. The frequency of mutant alleles in this cohort was significantly higher than that in the controls of East Asian and all population of gnomAD. All these variants were inherited from the asymptomatic mothers. Four male cases presented frequent seizures at onset, while the female case only had two fever-triggered seizures. They showed good responses to valproate and lamotrigine, then finally became seizure free. All the cases had no intellectual disability. Further analysis demonstrated that all previously reported destructive variants of BRWD3 caused intellectual disability, while missense variants located in WD40 repeat domains and bromodomains of BRWD3 were associated with epilepsy. CONCLUSION: BRWD3 gene is potentially associated with X-linked partial epilepsy without intellectual disability. The genotypes and locations of BRWD3 variants may explain for their phenotypic variation.

Weakness in both lower limbs for 1 week and blepharoptosis for 3 days in a boy aged 1 year and 7 months. / ç”·æ€§å¹¼å„¿åŒä¸‹è‚¢æ— åŠ›1周伴眼睑下垂3 d.

A boy, aged 1 year and 7 months, was hospitalized due to weakness in both lower limbs and blepharoptosis, which showed progressive aggravation and developed into irregular breathing. Neurological examinations showed lethargy, blepharoptosis, grade 4 muscle strength of both upper limbs, grade 3 muscle strength of both lower limbs, and disappearance of tendon reflex. Laboratory tests revealed albuminocytological dissociation in cerebrospinal fluid, disappearance of H reflex, and positive serum anti-GD1b IgG. The boy was finally diagnosed with Guillain-Barré syndrome (GBS) overlapping with Miller-Fisher syndrome and Bickerstaff brainstem encephalitis. He recovered and was discharged after treatment including immunoglobulin, plasma exchange, and respiratory support. The GBS overlap syndromes in children have strong clinical heterogeneity due to the injury of both peripheral nerve and brainstem, among which anti-GD1b antibody-related GBS overlap syndromes have special clinical manifestations and complex neuroelectrophysiological changes and are thus difficult to diagnose. Nerve conduction velocity tests, especially H reflex test, should be performed for children with weakness in both lower limbs and blepharoptosis.

[Progressive psychomotor regression for 2.5 years in a boy aged 5 years]. / 5岁男童进行性智力运动功能倒退2.5年.

A boy, aged 5 years, attended the hospital due to progressive psychomotor regression for 2.5 years. Motor function regression was the main manifestation in the early stage, and brain MRI and whole-exome sequencing (WES) of the family showed no abnormalities. After the age of 4 years and 9 months, the boy developed cognitive function regression, and brain MRI showed cerebellar atrophy. The reanalysis of WES results revealed a compound heterozygous mutation, [NM_000520, c.784C>T(p.His262Tyr]), c.1412C>T(p.Pro471Leu)], in the HEXA gene. The enzyme activity detection showed a significant reduction in the level of ß-hexosaminidase encoded by this gene. The boy was diagnosed with juvenile Tay-Sachs disease (TSD). TSD has strong clinical heterogeneity, and cerebellar atrophy may be an important clue for the diagnosis of juvenile TSD. The reanalysis of genetic data when appropriate based on disease evolution may improve the positive rate of WES.

[Fever for 2 months and disturbance of consciousness for 1 week in a preschool-aged girl].

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation syndrome (ROHHADS) is a rare multi-system disease, and delayed diagnosis and treatment may lead to catastrophic cardiopulmonary complications. As far as we know, no patient with ROHHADS has been reported in China, and this article reports a child with ROHHADS to improve the awareness of this disease among clinicians. A girl, aged 3 years, had the clinical manifestations of rapid weight gain, fever, disturbance of consciousness, and convulsion. The physical examination showed a body weight of 20 kg, somnolence, irregular breathing, and stiff neck. She had increased blood levels of prolactin and follicle-stimulating hormone and hyponatremia. The lumbar puncture showed an increased intracranial pressure. The brain MRI and magnetic resonance venography showed symmetrical lesions in the periventricular region and venous thrombosis in the right transverse sinus and the superior sagittal sinus. The sleep monitoring showed hypopnea. The girl was finally diagnosed with ROHHADS and intracranial venous thrombosis. She recovered after symptomatic treatment including decreasing intracranial pressure, anticoagulation, and respiratory support. The possibility of ROHHADS should be considered for patients with unexplained obesity, fever, and hypoventilation, with or without central nervous system symptoms. Early diagnosis and standardized follow-up can improve the prognosis of children with ROHHADS.

[A report of two children with fever, headache, and purpura].

In this study, two school-aged children had an acute onset in spring and had the manifestations of fever, headache, vomiting, disturbance of consciousness, purpura and ecchymosis, and positive meningeal irritation sign. There were increases in peripheral white blood cells and neutrophils, but reductions in the hemoglobin level and platelet count in the two children. They had a significant increase in C-reactive protein. There were hundreds or thousands of white blood cells in the cerebrospinal fluid, mainly neutrophils. Increased protein contents but normal levels of glucose and chloride in the cerebrospinal fluid were found. Head CT scan showed multiple hematomas in the right cerebellum and both hemispheres in one child. Bone marrow cytology indicated infection in the bone marrow, and both blood culture and bone marrow culture showed methicillin-resistant Staphylococcus aureus (MRSA). Both patients had cardiac murmurs and progressive reductions in the hemoglobin level and platelet count during treatment, and echocardiography showed the formation of vegetation in the aortic valve. Therefore, the patients were diagnosed with infectious endocarditis (IE). Vancomycin was used as the anti-infective therapy based on the results of drug sensitivity test. One child was cured after 6 weeks, and the other child was withdrawn from the treatment and then died. Dynamic monitoring of cardiac murmurs should be performed for children with unexplained fever, and echocardiography should be performed in time to exclude IE. IE should also be considered for children with purulent meningitis and skin and mucosal bleeding which cannot be explained by the reduction in platelet count.

[Hypertension and intermittent convulsions for one month in a school-age child].

Childhood polyarteritis nodosa (PAN) is a rare systemic vasculitis and the delayed diagnosis and treatment will cause high incidence of sequelae and high mortality. This article reports a girl with childhood PAN due to posterior reversible encephalopathy syndrome (PRES). The girl aged ten years was admitted to the hospital due to hypertension and convulsions for one month. She had complaints of headache, vomiting, and blurred vision before convulsions. At six months before admission, a mass was observed in the neck. The physical examination showed that she had hypertension and no abnormal findings in the central nervous system. The brain magnetic resonance imaging manifested long T1 and T2 signals, high signal intensities on fluid-attenuated inversion recovery (FLAIR) images, and iso-signal intensity on diffusion-weighted imaging in the white matter of the left occipital lobe. Therefore, the cause of convulsions was considered as PRES. Mass biopsy suggested PAN and no findings supported tuberculosis. The right kidney atrophy was observed by ultrasound examination. Emission computed tomography of the kidney showed multiple vascular stenosis and no blood perfusion in the right kidney, so PAN was confirmed. These findings suggest that PAN should be considered in patients with vasculitis who had involvements of multiple systems after excluding common vasculitis, such as Kawasaki disease and Henoch-Schönlein purpura. Biopsy and angiography should be performed as early as possible for timely diagnosis and treatment.

X-Linked Hereditary Motor Sensory Neuropathy Type 1 (CMTX1) in a Three-Generation Gelao Chinese Family.

In this report, we describe a three-generation family (the Gelao nationality, a minority ethnic group from Guizhou Province in the southwest China) with one affected member with Charcot-Marie-Tooth neuropathy X type 1 (CMTX1) in each generation. The three affected members carrying the R164W mutation in the Cx32 gene had different clinical symptoms. The proband, a 13-year-old boy presented recurrent episodes of transient central nervous system symptoms and concomitant transient diffuse white matter lesions on magnetic resonance imaging. His grandfather had the peripheral neurological presentations with later onset in the fourth decade, characterized by slowly progressive weakness of the distal muscles, atrophy, and foot deformities. But no sensory loss was observed. The proband's 38-year-old mother denied any neurological symptoms. The examination was normal except for pes cavus and diminished deep tendon reflexes in her lower limbs bilaterally. Genetic sequencing revealed the proband and his grandfather had a hemizygous mutation (p.164R > W) of CJB1 gene, and his mother had R164W heterozygous mutation. Our three cases denied symptoms of sensory disturbances, the sensory examination including touch, pin prick, and temperature sensation showed no obvious abnormalities. Thus, further investigation is needed to improve our understanding of the Cx32 protein function in the nervous system.