Detection of copy number variations in epilepsy using exome data.

Epilepsies are common neurological disorders and genetic factors contribute to their pathogenesis. Copy number variations (CNVs) are increasingly recognized as an important etiology of many human diseases including epilepsy. Whole-exome sequencing (WES) is becoming a standard tool for detecting pathogenic mutations and has recently been applied to detecting CNVs. Here, we analyzed 294 families with epilepsy using WES, and focused on 168 families with no causative single nucleotide variants in known epilepsy-associated genes to further validate CNVs using 2 different CNV detection tools using WES data. We confirmed 18 pathogenic CNVs, and 2 deletions and 2 duplications at chr15q11.2 of clinically unknown significance. Of note, we were able to identify small CNVs less than 10 kb in size, which might be difficult to detect by conventional microarray. We revealed 2 cases with pathogenic CNVs that one of the 2 CNV detection tools failed to find, suggesting that using different CNV tools is recommended to increase diagnostic yield. Considering a relatively high discovery rate of CNVs (18 out of 168 families, 10.7%) and successful detection of CNV with <10 kb in size, CNV detection by WES may be able to surrogate, or at least complement, conventional microarray analysis.

Clinical and mutational spectrum of Japanese patients with Charcot-Marie-Tooth disease caused by GDAP1 variants.

BACKGROUND: Mutations in GDAP1 are responsible for heterogeneous clinical and electrophysiological phenotypes of Charcot-Marie-Tooth disease (CMT), with autosomal dominant or recessive inheritance pattern. The aim of this study is to identify the clinical and mutational spectrum of CMT patients with GDAP1 variants in Japan. MATERIALS AND METHODS: From April 2007 to October 2014, using three state-of-art technologies, we conducted gene panel sequencing in a cohort of 1,030 patients with inherited peripheral neuropathies (IPNs), and 398 mutation-negative cases were further analyzed with whole-exome sequencing. RESULTS: We identified GDAP1 variants from 10 patients clinically diagnosed with CMT. The most frequent recessive variant in our cohort (5/10), c.740C>T (p.A247V), was verified to be associated with a founder event. We also detected three novel likely pathogenic variants: c.928C>T (p.R310W) and c.546delA (p.E183Kfs*23) in Case 2 and c.376G>A (p.E126K) in Case 8. Nerve conduction study or sural nerve biopsy of all 10 patients indicated axonal type peripheral neuropathy. CONCLUSION: We identified GDAP1 variants in approximately 1% of our cohort with IPNs, and established a founder mutation in half of these patients. Our study originally described the mutational spectrum and clinical features of GDAP1-related CMT patients in Japan.

Molecular genetic analysis of 30 families with Joubert syndrome.

Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.

Progressive atrophy of the cerebrum in 2 Japanese sisters with microcephaly with simplified gyri and enlarged extraaxial space.

This is a case report that describes 2 sisters with microcephaly, simplified gyri, and enlarged extraaxial space. Clinical features of the cases include dysmorphic features, congenital microcephaly, failure of postnatal brain growth, neonatal onset of seizures, quadriplegia, and severe psychomotor delay. Neuroradiological imaging demonstrated hypoplasia of bilateral cerebral hemispheres with enlarged extraaxial spaces, simplified gyral patterns without a thickened cortex, hypoplastic corpus callosum, and enlarged lateral ventricles, with a reduction in gray and white matter volume during the prenatal and neonatal periods. Repeat MRI revealed progressive atrophy of the cerebral gray and white matter, with enlarged lateral ventricles, although the sizes of the bilateral basal ganglia, thalamus, and infratentorial structures were relatively preserved. These neuroradiological findings imply that this disease is caused by the gene involved in neuronal and glial proliferation in the ventricular zone and in tangential neuronal migration from the ganglionic eminence. The nature of the progressive degeneration of the hemispheric structures should be clarified.

The cytokine and chemokine profiles in rhabdomyolysis in a patient with Gaucher disease type II.

This report describes a patient with Gaucher disease type II who developed severe rhabdomyolysis. We treated him successfully and measured various cytokine and chemokine levels sequentially to elucidate the pathophysiology of rhabdomyolysis. The serum levels of interleukin-6, -8, -10, granulocyte colony-stimulating factor, interferon-gamma, and monocyte chemoattractant protein-1 were markedly elevated in the early phase of rhabdomyolysis. These findings indicate that cytokines and chemokines are related to the massive myolysis and regenerating process. A viral infection may have triggered rhabdomyolysis through exaggerated activation of macrophages in our patient. The profiles of cytokines and chemokines should be examined in further cases to increase our understanding of the pathophysiology of rhabdomyolysis.

Efficacy of continuous acyclovir infusion in neonatal herpes virus encephalitis.

We have successfully eliminated herpes simplex virus-2 from the central nervous system in a case of neonatal herpes simplex virus encephalitis with a continuous acyclovir infusion. A male infant delivered from a healthy 22-year-old woman without genital or systemic herpes symptoms around delivery began to develop fever and intractable seizures. He was started on intermittent intravenous acyclovir (20 mg/kg every 8 h) based on the diagnosis of herpes encephalitis. The virus was not eliminated with intermittent acyclovir and vidarabine, while continuous acyclovir was ultimately effective in eliminating herpes simplex virus from his central nervous system. This report demonstrates the efficacy of continuous acyclovir infusion in neonatal herpes simplex virus encephalitis.

Hypomyelination with atrophy of the basal ganglia and cerebellum: follow-up and pathology.

BACKGROUND AND OBJECTIVE: Hypomyelination with atrophy of the basal ganglia and cerebellum is a recently defined disorder. Only a few patients have been described. We report on 11 additional patients and new MRI findings and provide histopathologic confirmation of the MRI interpretation. METHODS: We reviewed the patients' clinical history and present findings. We scored the MRI abnormalities. The histopathology of one patient was re-examined. RESULTS: The patients' early psychomotor development was normal or delayed, followed by increasing extrapyramidal movement abnormalities, ataxia, and spasticity. Mental capacities were variably affected. MRI showed hypomyelination with, on follow-up, evidence of further myelin loss and variable white matter atrophy. The putamen was small or, more often, absent; the head of the caudate nucleus was decreased in size. In contrast, the thalamus and globus pallidus remained normal. Cerebellar atrophy was invariably present. Histopathology confirmed the myelin deficiency, probably related to both lack of deposition and low-grade further loss. The degeneration of putamen was subtotal. The cerebellar cortex was affected, particularly the granular layer. CONCLUSION: Hypomyelination with atrophy of the basal ganglia and cerebellum is a syndrome diagnosed by distinctive MRI findings. Histopathology confirms hypomyelination, low-grade further myelin loss, subtotal degeneration of the putamen, and cerebellar cortical atrophy. All known patients are sporadic, and the mode of inheritance is unclear.

Mutation in the caveolin-3 gene causes a peculiar form of distal myopathy.

The authors describe a patient with sporadic distal myopathy associated with reduced caveolin-3 in muscle fibers in which the muscle atrophy was restricted to the small muscles of the hands and feet. Gene analysis disclosed a heterozygous 80 G-->A substitution in the caveolin-3 gene that was identical to that of reported cases of elevated serum creatine kinase. This patient further demonstrated possible clinical heterogeneity of myopathies with mutations in the caveolin-3 gene.

Mechanism of tonic spasms in West syndrome viewed from ictal SPECT findings.

To clarify the pathophysiology of tonic spasms, 21 patients with West syndrome were analyzed using ictal and interictal single photon emission computed tomography (SPECT). We focused on whether ictal perfusion changes were observed in the focal cortical region. Eight of the patients studied showed definite focal cortical ictal hyperperfusion, indicating that there is a unique subset of West syndrome that can be classified as infantile localization-related epilepsy. Of those eight patients, only two showed asymmetric spasms, suggesting that seizure symptomatology in infants gives only limited information on the localization-related nature of epilepsy. Furthermore, the activation of subcortical structures by focal cortical regions might be attributable to the symmetric seizure phenomena. Thirteen patients showed a diffuse pattern in their ictal SPECTs; this probably included patients with diffuse hyperperfusion and those with no changes. The following have yet to be determined: (1) whether West syndrome is divided into subgroups based on the origin of spasms, in that some patients have the origin in the cortical hemisphere and some have the origin in structures other than the cortical hemisphere, such as the brain stem; (2) whether differences in ictal SPECT patterns reflect a unique nature of tonic spasms in West syndrome, where tonic spasms appear in clusters and the interval of each spasm is different among each patient.

A novel mutation in glial fibrillary acidic protein gene in a patient with Alexander disease.

Alexander disease is a rare, progressive, leukoencephalopathy whose hallmark is the widespread accumulation of Rosenthal fibers. The most common form affects infants and young children, and is characterized by progressive failure of central myelination, usually leading to death before adulthood. Definitive diagnosis of Alexander disease has required biopsy or autopsy to demonstrate the presence of Rosenthal fibers. However, missense mutations in the coding region of the glial fibrillary acidic protein (GFAP) gene have recently been associated with a high percentage of pathologically proven cases. Here we report that a 10-year-old Japanese patient who showed clinical signs of Alexander disease is heterozygous for a C to T transition in which predicts a novel A244V amino acid substitution in the conserved 2A alpha-helix domain of GFAP. The nucleotide change was not found in 65 normal individuals (130 alleles). These results provide further support for a causative role for GFAP mutations in Alexander disease, and suggest DNA sequencing as an alternative diagnostic to biopsy.

Fas-independent apoptosis induced by UVC in p53-mutated human epithelial tumor A431 cells through activation of caspase-8 and JNK/SAPK.

A431 cells/UVC-induced apoptosis/Caspase 8/Fas/JNK/PAPK. We previously observed that p53-mutated human epithelial tumor A431 cells underwent apoptosis after ultraviolet C (UVC) irradiation through the caspases-8 and -3 pathway. Fas/FasL is known to initiate apoptosis in several cell lines via caspase-8 activation. Then, to determine if Fas/FasL mediates apoptosis in A431. we investigated Fas expression and modulation in UVC-irradiated A431 cells. A431 constitutively expressed Fas, which gradually decreased after UVC-irradiation. Pretreatment with a neutralizing anti-Fas antibody, ZB4, did not abrogate the UVC-induced apoptosis. An agonistic anti-Fas antibody, CH11, very slowly induced apoptosis in A431. suggesting that the constitutively expressed Fas had a low functional potential. Hence, UVC-induced apoptosis in A431 seems to occur independent of the Fas signal. Interestingly, however, a pretreatment with CH11 remarkably potentiated UVC-induced apoptosis. An inhibitor of caspase-8, Ac-IETD-CHO, partially inhibited UVC-induced apoptosis. JNK was phosphorylated immediately after exposure to UVC. prior to apoptotic chromatin condensation. Our data suggest that the activation of caspase-8 occurs independent of Fas upregulation, and that JNK/ SAPK contributes to UVC-induced apoptosis in human epithelial A431 cells.

Prenatal radiation-induced limb defects mediated by Trp53-dependent apoptosis in mice.

We reported previously that in utero radiation-induced apoptosis in the predigital regions of embryonic limb buds was responsible for digital defects in mice. To investigate the possible involvement of the Trp53 gene, the present study was conducted using embryonic C57BL/6J mice with different Trp53 status. Susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depended on both Trp53 status and the radiation dose; i.e., Trp53 wild-type (Trp53(+/+)) mice appeared to be the most sensitive, Trp53 heterozygous (Trp53(+/-)) mice were intermediate, and Trp53 knockout (Trp53(-/-)) mice were the most resistant. These results indicate that induction of apoptosis and digital defects by prenatal irradiation in the later period of organogenesis are mediated by the Trp53 gene. These findings suggest that the wild-type Trp53 gene may be an intrinsic genetic susceptibility factor that is responsible for certain congenital defects induced by prenatal irradiation.

Combined therapy with hypothermia and anticytokine agents in influenza A encephalopathy.

Two children with influenza A-related encephalopathy were treated with a combination of mild hypothermia (deep body temperature of the forehead: 35 degrees C) and anticytokine agents (high-dose methylprednisolone and ulinastatin), while receiving amantadine. One of the cases exhibited acute necrotizing encephalopathy on computed tomography (CT). Although no severe complications occurred, correctable hypokalemia and hyperglycemia occurred in both cases. Both patients recovered without any neurological sequelae. Our therapeutic protocol appears to be effective for managing influenza A-related encephalopathy.

Adaptive response in embryogenesis. III. Relationship to radiation-induced apoptosis and Trp53 gene status.

We reported previously that a radiation-induced adaptive response existed in the late period of embryogenesis, and that radiation-induced apoptosis in the predigital regions was responsible for digital defects in embryonic ICR mice. To investigate the possible involvement of the Trp53 gene and radiation-induced apoptosis in radiation-induced adaptive responses in embryogenesis, the present study was conducted using Trp53 wild-type (Trp53(+/+)) and Trp53 heterozygous (Trp53(+/-)) embryonic mice of the C57BL/6 strain. The existence of a radioadaptive response in the Trp53(+/+) embryonic mice was demonstrated by irradiating the embryos with 5 or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. The two conditioning doses at 5 and 30 cGy significantly suppressed the induction of apoptosis by the challenging dose in the predigital regions of limb buds in the Trp53(+/+) embryonic mice, while no such effect was found in the Trp53(+/-) embryonic mice. These findings indicate that induction of a radioadaptive response in embryogenesis is related to Trp53 gene status and the occurrence of radiation-induced apoptosis.

The perfusion defect seen with SPECT in West syndrome is not correlated with seizure prognosis or developmental outcome.

We used interictal single photon emission computed tomography (SPECT) on 40 patients with West syndrome to determine whether cortical perfusion abnormalities are closely related to the development of West syndrome and whether they are correlated with the long-term seizure prognosis or the developmental outcome. Localized cortical perfusion abnormalities were seen in 24 patients (60%), while 15 patients (38%) were classified as normal. The remaining patient showed hyperperfusion of the basal ganglia bilaterally. Of 24 patients with localized perfusion abnormalities, unifocal cortical hypoperfusion was present in 11, multifocal hypoperfusion in 10, multiple cortical hypo- and hyperperfusion in one, hyperperfusion of the bilateral frontal cortices and brain stem in one, and focal hyperperfusion in the residual frontal cortex in one. For statistical analysis, we focused on 26 patients (cryptogenic; 10, symptomatic; 16), who were followed for more than 2 years after the onset of tonic spasms (mean 5.0 years). The results showed that focal cortical perfusion abnormalities were not correlated with the long-term seizure prognosis, the developmental outcome, or the response to ACTH therapy. In agreement with previous reports, the results of interictal SPECT suggested that focal cortical lesions play an important role in the development of West syndrome. However, statistical analysis showed that the existence of cortical dysfunction as defined by SPECT did not predict the seizure prognosis or the developmental outcome.

UVC-induced apoptosis in human epithelial tumor A431 cells: sequence of apoptotic changes and involvement of caspase (-8 and -3) cascade.

Human epidermoid tumor A431 cells underwent apoptosis following exposure to ultraviolet C (UVC). The apoptosis was of the interphase death type, and mostly occurred within one cell cycle, independent of the cell-cycle phases. We further examined the detailed sequential order of apoptotic changes in cells after UVC exposure and the involvement of caspases using six caspase inhibitors. The loss of mitochondrial transmembrane potential (delta psi m) appeared in the earliest phase; subsequently, the chromatin condensation and DNA-fragmentation occurred. Cell shrinkage and loss of the plasma-membrane integrity, judged by propidium iodide (PI) staining, were observed in the later phase. A broad-spectrum caspase inhibitor, z-VAD-fmk, completely prevented all apoptotic changes, except for the depletion of delta psi m. Both Ac-DEVD-CHO and Ac-IETD-CHO, inhibitors of caspase -3 and -8, respectively, effectively inhibited typical chromatin condensation to almost the same extent. However, the nuclei still showed partial condensation. A caspase -9 inhibitor, Ac-LEHD-CHO, did not prevent chromatin condensation, though it partially inhibited cell-size reduction and PI-stainability. None of the caspase inhibitors could inhibit the delta psi m reduction. These results strongly suggest that the collapse of delta psi m is not a part of the central apoptotic machinery, and that caspase cascade(s), especially caspase-8 to -3, play an important role in UVC-induced apoptosis in A431.