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Biallelic POLR3B mutations cause a rare hypomyelinating leukodystrophy. De novo POLR3B heterozygous mutations were recently associated with afferent ataxia, spasticity, variable intellectual disability, and epilepsy, and predominantly demyelinating sensorimotor peripheral neuropathy.We performed whole-exome sequencing (WES) of DNA samples from 804 Charcot-Marie-Tooth (CMT) cases that could not be genetically diagnosed by DNA-targeted resequencing microarray using next-generation sequencers. Using WES data, we analyzed the POLR3B mutations and confirmed their clinical features.We identified de novo POLR3B heterozygous missense mutations in two patients. These patients presented with early-onset demyelinating sensorimotor neuropathy without ataxia, spasticity, or cognitive impairment. Patient 1 showed mild cerebellar atrophy and spinal cord atrophy on magnetic resonance imaging and eventually died of respiratory failure in her 50s. We classified these mutations as pathogenic based on segregation studies, comparison with control database, and in silico analysis.Our study is the third report on patients with demyelinating CMT harboring heterozygous POLR3B mutations and verifies the pathogenicity of POLR3B mutations in CMT. Although extremely rare in our large Japanese case series, POLR3B mutations should be added to the CMT-related gene panel for comprehensive genetic screening, particularly for patients with early-onset demyelinating CMT.

Mitochondrial disorders are a group of clinically and genetically heterogeneous multisystem disorders and peripheral neuropathy is frequently described in the context of mutations in mitochondrial-related nuclear genes. This study aimed to identify the causative mutations in mitochondrial-related nuclear genes in suspected hereditary peripheral neuropathy patients. We enrolled a large Japanese cohort of clinically suspected hereditary peripheral neuropathy patients who were mutation negative in the prescreening of the known Charcot–Marie–Tooth disease-causing genes. We performed whole-exome sequencing on 247 patients with autosomal recessive or sporadic inheritance for further analysis of 167 mitochondrial-related nuclear genes. We detected novel bi-allelic likely pathogenic/pathogenic variants in four patients, from four mitochondrial-related nuclear genes: pyruvate dehydrogenase beta-polypeptide (PDHB), mitochondrial poly(A) polymerase (MTPAP), hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase, beta subunit (HADHB), and succinate-CoA ligase ADP-forming beta subunit (SUCLA2). All these patients showed sensory and motor axonal polyneuropathy, combined with central nervous system or multisystem involvements. The pathological analysis of skeletal muscles revealed mild neurogenic changes without significant mitochondrial abnormalities. Targeted screening of mitochondria-related nuclear genes should be considered for patients with complex hereditary axonal polyneuropathy, accompanied by central nervous system dysfunctions, or with unexplainable multisystem disorders.

Some hereditary transthyretin (ATTRv) amyloidosis patients are misdiagnosed as Charcot-Marie-Tooth disease (CMT) at onset. We assess the findings to identify ATTRv amyloidosis among patients with suspected CMT to screen transthyretin gene variants for treatments.We assessed clinical, cerebrospinal fluid, and electrophysiological findings by comparing ATTRv amyloidosis patients with suspected CMT (n = 10) and CMT patients (n = 489).The median (interquartile range) age at onset of neurological symptoms was 69 (64.2-70) years in the ATTRv amyloidosis vs 12 (5-37.2) years in CMT group (Mann-Whitney U, p 0.01). The proportion of patients with initial sensory symptoms was 70% in the ATTRv amyloidosis group vs 7.1% in CMT group (Fisher's exact, p 0.01). The proportion of patients with histories of suspected chronic inflammatory demyelinating polyneuropathy (CIDP) were 50% in the ATTRv amyloidosis group vs 8.7% in CMT group (Fisher's exact, p .01). Other measures and outcomes were not different between the two groups. Five of the six patients with ATTRv amyloidosis received treatment and survived.For effective treatments, the transthyretin gene should be screened in patients with suspected CMT with old age at onset of neurological symptoms, initial sensory symptoms, and histories of suspected CIDP.

BackgroundNOTCH2NLCGGC repeat expansions have been associated with various neurogenerative disorders, including neuronal intranuclear inclusion disease and inherited peripheral neuropathies (IPNs). However, only a fewNOTCH2NLC-related disease studies in IPN have been reported, and the clinical and genetic spectra remain unclear. Thus, this study aimed to describe the clinical and genetic manifestations ofNOTCH2NLC-related IPNs.MethodAmong 2692 Japanese patients clinically diagnosed with IPN/Charcot–Marie–Tooth disease (CMT), we analysedNOTCH2NLCrepeat expansion in 1783 unrelated patients without a genetic diagnosis. Screening and repeat size determination ofNOTCH2NLCrepeat expansion were performed using repeat-primed PCR and fluorescence amplicon length analysis-PCR.ResultsNOTCH2NLCrepeat expansions were identified in 26 cases of IPN/CMT from 22 unrelated families. The mean median motor nerve conduction velocity was 41 m/s (range, 30.8–59.4), and 18 cases (69%) were classified as intermediate CMT. The mean age of onset was 32.7 (range, 7–61) years. In addition to motor sensory neuropathy symptoms, dysautonomia and involuntary movements were common (44% and 29%). Furthermore, the correlation between the age of onset or clinical symptoms and the repeat size remains unclear.ConclusionsThese findings of this study help us understand the clinical heterogeneity ofNOTCH2NLC-related disease, such as non-length-dependent motor dominant phenotype and prominent autonomic involvement. This study also emphasise the importance of genetic screening, regardless of the age of onset and type of CMT, particularly in patients of Asian origin, presenting with intermediate conduction velocities and dysautonomia.

The development of several-nanometer-scale π-conjugated systems for efficient intramolecular hopping charge transport remains a significant challenge. To construct localized electronic structures at the same energy in a molecule, a series of oligothiophenes, with lengths up to 10 nm and periodically twisted structures, was synthesized. Single-molecule conductance measurements of the twisted molecules revealed resistances lower than those of planar oligothiophenes. This study provides a rational molecular design to improve the intramolecular hopping charge transport in materials.

We aimed to reveal the genetic features associated with MPZ variants in Japan. From April 2007 to August 2017, 64 patients with 23 reported MPZ variants and 21 patients with 17 novel MPZ variants were investigated retrospectively. Variation in MPZ variants and the pathogenicity of novel variants was examined according to the American College of Medical Genetics standards and guidelines. Age of onset, cranial nerve involvement, serum creatine kinase (CK), and cerebrospinal fluid (CSF) protein were also analyzed. We identified 64 CMT patients with reported MPZ variants. The common variants observed in Japan were different from those observed in other countries. We identified 11 novel pathogenic variants from 13 patients. Six novel MPZ variants in eight patients were classified as likely benign or uncertain significance. Cranial nerve involvement was confirmed in 20 patients. Of 30 patients in whom serum CK levels were evaluated, eight had elevated levels. Most of the patients had age of onset >20 years. In another subset of 30 patients, 18 had elevated CSF protein levels; four of these patients had spinal diseases and two had enlarged nerve root or cauda equina. Our results suggest genetic diversity across patients with MPZ variants., Genetic spectrum of MPZ variants was confirmed in this study.

Heterozygous mutations in the Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) gene have been reported with different clinical phenotypes including Silver syndrome (SS)/spastic paraplegia 17 (SPG17), distal hereditary motor neuropathy type V (dHMN-V), and Charcot-Marie-Tooth (CMT) disease type 2. We screened 407 Japanese patients who were clinically suspected of having CMT by exome sequencing and searched mutations in BSCL2. As a result, we identified five patients with heterozygous mutations in BSCL2. We confirmed three cases of known mutations (p.N88S and p.S90L) and two cases of novel mutations (p.N88T and p.S141A). The clinical features of the cases with known mutations in Japan were similar to those previously reported in other countries. In particular, there were many cases with sensory disturbance. The case with p.N88T mutation showed severe phenotype such as early onset age and prominent vocal cord paresis. The case with p.S141A mutation showed characteristics of demyelinating neuropathy such as CMT disease type 1 by electrophysiological examination. In this article, we report the clinical features and spread of cases with BSCL2 mutation in a Japanese cohort.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by the BCR-ABL1 tyrosine kinase1,2. ABL1-selective tyrosine kinase inhibitors (TKIs) including nilotinib have dramatically improved the prognosis of patients with CML3–7. The ultimate goal of CML treatment is likely to be TKI-free maintenance of deep molecular response (DMR), which is defined by quantitative measurement of BCR-ABL1 transcripts on the international scale (IS)8, and durable DMR is a prerequisite to reach this goal9. Thus, an algorithm to enable the early prediction of DMR achievement on TKI therapy is quite valuable. Here, we show that our mathematical framework based on a clinical trial dataset10 can accurately predict the response to frontline nilotinib. We found that our simple dynamical model can predict nilotinib response by using two common laboratory findings (observation values): IS11,12 and white blood cell (WBC) count. Furthermore, our proposed method identified patients who failed to achieve DMR with high fidelity according to the data collected only at three initial time points during nilotinib therapy. Since our model relies on the general properties of TKI response, our framework would be applicable to CML patients who receive frontline nilotinib or other TKIs in clinical practice.Significance StatementChronic myeloid leukemia (CML) is a myeloproliferative disorder caused by the BCR-ABL1 tyrosine kinase. The goal of this treatment is the sequential achievement of deep molecular response (DMR). Tyrosine kinase inhibitors (TKIs) are effective in the reduction because they inhibit CML cell proliferation. However, because of individual differences in the TKI efficacy, some patients are unable to achieve DMR, so that early prediction of DMR reachability is necessary for personalized medicine. By combining time series analysis and mathematical modeling, we developed a mathematical method that accurately predicts patients who do not achieve DMR in the early stages of TKI administration. Our prediction method gives a basis of effective personalized treatments for CML patients.

Objectives Eltrombopag, a thrombopoietin-receptor agonist, stimulates hematopoiesis in patients with acquired aplastic anemia (AA). Cytomorphologic changes in bone marrow after eltrombopag administration are still unclear. This study examined the effect of eltrombopag on cytomorphologic findings using data from prior phase 2 studies (E1201 and E1202). Methods Microscopic examinations were performed in 31 patients with AA (E1201 [n = 21], E1202 [n = 10]). The relationship between hematologic improvement and morphologic findings was also investigated. Results In 5 patients (E1201 [n = 3], E1202 [n = 2]), the bone marrow blast count increased after initiation of eltrombopag treatment compared with screening values. The blast count was less than 5%, and the increase in bone marrow blasts was transient in all 4 patients who had bone marrow examinations at follow-up. In 8 patients (E1201 [n = 5], E1202 [n = 3]), dysplastic forms of megakaryocytes were found in the bone marrow following treatment initiation. Dysmegakaryopoiesis of 10% or more was found in 3 patients. None of the patients revealed micromegakaryocytes. Ten patients showed an increase in bone marrow blasts and/or dysmegakaryopoiesis following treatment initiation. Nine of 10 patients showed hematologic improvement in 1 or more lineages. Conclusions Dysmegakaryopoiesis without micromegakaryocytes and a transient increase of less than 5% in bone marrow blast count may be signs of hematologic improvement with eltrombopag for patients with AA.

Mutations in neurofilament genes have been linked to several neuromuscular disorders. The neurofilament heavy (NEFH) gene was identified as the causative gene of Charcot-Marie-Tooth disease type 2CC (CMT2CC) in 2016, with a toxic gain of function mechanism caused by the translation and aggregation of cryptic amyloidogenic element (CAE) in the 3' untranslated region (UTR). But the NEFH-related clinical and genetic spectrums are still unclear in Japan.We analyzed all variants in the NEFH gene from our in-house whole-exome sequencing data, established from Japanese nationwide patients with neuromuscular disorders, including Charcot-Marie-Tooth (CMT) disease and spinal muscular atrophy (SMA).We identified a c.3017dup (p.Pro1007Alafs*56) variant in NEFH from three families clinically diagnosed with CMT, and one family with SMA. In addition to the patients presented with typical peripheral neuropathies, pyramidal signs were observed from one CMT patient. Whereas the SMA patients showed severe characteristic weakness of triceps brachii and quadriceps femoris. All of these four families reside in Kagoshima Prefecture of Japan, and a following haplotype analysis strongly suggests a founder effect.This is the original report referring to a founder mutation in NEFH. The clinical diversity in our study, comprising CMT, with or without pyramidal signs, and SMA, suggest an extensive involvement of peripheral nerve, anterior horn cells, or both. Our findings broaden the phenotypic spectrum of NEFH-related disorders.

Mutations in the HADHB gene induce dysfunctions in the beta-oxidation of fatty acids and result in a MTP deficiency, which is characterized by clinical heterogeneity, such as cardiomyopathy and recurrent Leigh-like encephalopathy. In contrast, milder forms of HADHB mutations cause the later onset of progressive axonal peripheral neuropathy (approximately 50-80%) and myopathy with or without episodic myoglobinuria. The mechanisms linking neuronal defects in these diseases to the loss of HADHB function currently remain unclear. Drosophila has the CG4581 (dHADHB) gene as a single human HADHB homologue. We herein established pan-neuron-specific dHADHB knockdown flies and examined their phenotypes. The knockdown of dHADHB shortened the lifespan of flies, reduced locomotor ability and also limited learning abilities. These phenotypes were accompanied by an abnormal synapse morphology at neuromuscular junctions (NMJ) and reduction in both ATP and ROS levels in central nervous system (CNS). The Drosophila NMJ synapses are glutamatergic that is similar to those in the vertebrate CNS. The present results reveal a critical role for dHADHB in the morphogenesis and function of glutamatergic neurons including peripheral neurons. The dHADHB knockdown flies established herein provide a useful model for investigating the pathological mechanisms underlying neuropathies caused by a HADHB deficiency.

Recently, a doping of sodium ion (Na+) into the perovskite solar cells has attracted much attention. Supposing that the Na+ ions substitute the A-site cation of the perovskite structure, the Na+ doping is expected to enlarge a bandgap of perovskite layer. Additionally, the Na+ doping may increase the grain size and decrease the trap density. We recently reported a new 3-step method using additional spin-coating of a HC(NH2)2I (FAI) solution on a 2-step prepared CH3NH3PbI3 (MAPbI3) layer containing an unreacted PbI2, which produced a multiple bandgap structure by forming a FA-rich layer with a smaller bandgap near the electron transport layer. Here, we attempted to form the top layer with larger bandgap by adding a small amount of NaI into the FAI solution for the third step and investigated the effect of NaI post-treatment on the perovskite layer. The NaI addition slightly enlarged the bandgap of surface of the perovskite layer. Additionally, it accelerated the grain growth and effectively decreased grain...

We report a case of a 60-year-old man who presented with symptoms of memory loss, gait disorder, and sluggish movement. We considered both Parkinson's disease and multiple system atrophy as possible diagnoses and consequently hospitalized the patient owing to the worsening symptoms and the development of consciousness disorder. During the course of the disease, dementia, loss of consciousness, and movement disorders worsened rapidly within one year after admission, and the patient eventually developed mutism. The significant clinical characteristics of our case included no myoclonus and involuntary tremors in the extremities. There was no periodic synchronous discharge on electro-encephalography and cranial MRI with diffusion-weighted images showed no high-intensity findings in cortex. Prion protein genetic analysis identified four repeated insertional mutations in the octapeptide repeat (OPR) region, and the patient was diagnosed with inherited Creutzfeldt-Jakob disease. Cases of OPR insertional mutations are a few in Japan and occur in about 10% of population in Europe. Creutzfeldt-Jakob disease with OPR insertional mutation shows various clinical manifestations and atypical findings on electroencephalography and cranial MRI. Diagnosing for Creutzfeldt-Jakob disease with OPR insertional mutation is important in Prion protein genetic analysis.

Objective To identify the genetic characteristics in a large-scale of patients with Charcot-Marie-Tooth disease (CMT).MethodsFrom May 2012 to August 2016, we collected 1005 cases with suspected CMT throughout Japan, whereas PMP22 duplication/deletion were excluded in advance for demyelinating CMT cases. We performed next-generation sequencing targeting CMT-related gene panels using Illumina MiSeq or Ion Proton, then analysed the gene-specific onset age of the identified cases and geographical differences in terms of their genetic spectrum.Results From 40 genes, we identified pathogenic or likely pathogenic variants in 301 cases (30.0%). The most common causative genes were GJB1 (n=66, 21.9%), MFN2 (n=66, 21.9%) and MPZ (n=51, 16.9%). In demyelinating CMT, variants were detected in 45.7% cases, and the most common reasons were GJB1 (40.3%), MPZ (27.1%), PMP22 point mutations (6.2%) and NEFL (4.7%). Axonal CMT yielded a relatively lower detection rate (22.9%), and the leading causes, occupying 72.4%, were MFN2 (37.2%), MPZ (9.0%), HSPB1 (8.3%), GJB1 (7.7%), GDAP1 (5.1%) and MME (5.1%). First decade of life was found as the most common disease onset period, and early-onset CMT cases were most likely to receive a molecular diagnosis. Geographical distribution analysis indicated distinctive genetic spectrums in different regions of Japan.Conclusions Our results updated the genetic profile within a large-scale of Japanese CMT cases. Subsequent analyses regarding onset age and geographical distribution advanced our understanding of CMT, which would be beneficial for clinicians.

Background and purpose X-linked Charcot-Marie-Tooth disease type 1 (CMTX1), caused by mutations in gap junction protein beta 1 (GJB1), is characterized by various central nervous system symptoms and gender differences of clinical severity. The aim of this study was to identify the frequency and mutation spectrum of CMTX1 patients in Japan and to demonstrate their phenotypic diversities. Methods Using three high-throughput sequencing systems, targeted gene panel sequencing on 1483 unrelated index patients with suspected Charcot-Marie-Tooth (CMT) disease was performed. The peripheral and central nervous system involvements of all patients with GJB1 variants were assessed retrospectively and a detailed gender comparison was conducted with the CMT examination score. Results Twenty-three novel and 36 described GJB1 variants were identified from 88 pedigrees, in which 34 female and 78 male patients were enrolled. Mean age at onset of the male patients was much younger than the females, 21.56 ± 17.63 years vs. 35.53 ± 23.72 years (P = 0.007). Male patients presented with more severe phenotypes in every examination item, but statistical differences were observed only in motor dysfunctions of the lower extremities and vibration sensation. No significant sensory difference was identified between genders, either clinically or electrophysiologically. Central nervous system dysfunctions were found in 15 patients from 12 pedigrees. Therein, six patients developed stroke-like phenotypes, with dysarthria as the leading symptom. Conclusions A relatively lower frequency of CMTX1 (5.9%) was demonstrated and a broad mutation spectrum of GJB1 was described. Detailed clinical differences between genders and various central nervous system symptoms were also illustrated, even in the same pedigree.

Higuchi et al. identify recessive mutations in the mitochondrial gene, cytochrome c oxidase assembly factor 7 (COA7) in four unrelated patients with an axonal-type motor and sensory neuropathy with ataxia. Genetic, histopathological, radiological and functional data support a causative role for loss-of-function COA7 mutations in the observed phenotype., Several genes related to mitochondrial functions have been identified as causative genes of neuropathy or ataxia. Cytochrome c oxidase assembly factor 7 (COA7) may have a role in assembling mitochondrial respiratory chain complexes that function in oxidative phosphorylation. Here we identified four unrelated patients with recessive mutations in COA7 among a Japanese case series of 1396 patients with Charcot-Marie-Tooth disease (CMT) or other inherited peripheral neuropathies, including complex forms of CMT. We also found that all four patients had characteristic neurological features of peripheral neuropathy and ataxia with cerebellar atrophy, and some patients showed leukoencephalopathy or spinal cord atrophy on MRI scans. Validated mutations were located at highly conserved residues among different species and segregated with the disease in each family. Nerve conduction studies showed axonal sensorimotor neuropathy. Sural nerve biopsies showed chronic axonal degeneration with a marked loss of large and medium myelinated fibres. An immunohistochemical assay with an anti-COA7 antibody in the sural nerve from the control patient showed the positive expression of COA7 in the cytoplasm of Schwann cells. We also observed mildly elevated serum creatine kinase levels in all patients and the presence of a few ragged-red fibres and some cytochrome c oxidase-negative fibres in a muscle biopsy obtained from one patient, which was suggestive of subclinical mitochondrial myopathy. Mitochondrial respiratory chain enzyme assay in skin fibroblasts from the three patients showed a definitive decrease in complex I or complex IV. Immunocytochemical analysis of subcellular localization in HeLa cells indicated that mutant COA7 proteins as well as wild-type COA7 were localized in mitochondria, which suggests that mutant COA7 does not affect the mitochondrial recruitment and may affect the stability or localization of COA7 interaction partners in the mitochondria. In addition, Drosophila COA7 (dCOA7) knockdown models showed rough eye phenotype, reduced lifespan, impaired locomotive ability and shortened synaptic branches of motor neurons. Our results suggest that loss-of-function COA7 mutation is responsible for the phenotype of the presented patients, and this new entity of disease would be referred to as spinocerebellar ataxia with axonal neuropathy type 3.

Mutations in small heat shock protein beta-1 (HspB1) have been linked to Charcot-Marie-Tooth (CMT) disease type 2F and distal hereditary motor neuropathy type 2B. Only four cases with HSPB1 mutations have been reported to date in Japan. In this study between April 2007 and October 2014, we conducted gene panel sequencing in a case series of 1,030 patients with inherited peripheral neuropathies (IPNs) using DNA microarray, targeted resequencing, and whole-exome sequencing. We identified HSPB1 variants in 1.3% (13 of 1,030) of the patients with IPNs, who exhibited a male predominance. Based on neurological and electrophysiological findings, seven patients were diagnosed with CMT disease type 2F, whereas the remaining six patients were diagnosed with distal hereditary motor neuropathy type 2B. P39L, R127W, S135C, R140G, K141Q, T151I, and P182A mutations identified in 12 patients were described previously, whereas a novel K123* variant with unknown significance was found in 1 patient. Diabetes and impaired glucose tolerance were detected in 6 of the 13 patients. Our findings suggest that HSPB1 mutations result in two phenotypes of inherited neuropathies and extend the phenotypic spectrum of HSPB1-related disorders.

In the conventional two-step prepared perovskite solar cells, the CH3NH3PbI3 (MAPbI3) film usually contains an unreacted PbI2 at the interface between an electron transport layer (ETL) and a perovskite active layer. To reduce the unreacted PbI2 in the two-step prepared MAPbI3 film, we have recently reported a new three-step method, which was realized by an additional MA(I,Br) spin-coating. Here, we propose an advanced three-step method, viz., an additional HC(NH2)2I (FAI) spin-coating on the two-step prepared MAPbI3 film. The additional FAI spin-coating formed a FAxMA1–xPbI3 solid solution by the incorporation of FA ion into MAPbI3. Also, the additional FAI spin-coating yielded a FAyMA1–yPbI3 layer (y > x) by converting the unreacted PbI2, which resulted in the layered structure with different FA concentrations and hence, with the multiple bandgap structure. The best PCE of 18.1% was achieved by optimizing the FAI spin-coating process.

SH3TC2, known as the causative gene of autosomal recessive demyelinating Charcot-Marie-Tooth type 4C (CMT4C), was also found linked to a mild mononeuropathy of the median nerve with an autosomal dominant inheritance pattern. Using DNA microarray, Illumina MiSeq, and Ion proton, we carried out gene panel sequencing among 1483 Japanese CMT patients, containing 397 patients with demyelinating CMT. From seven patients with demyelinating CMT, we identified eight recessive variants in the SH3TC2 gene, consisting of five novel (pathogenic/likely pathogenic) and three reported variants. Additionally, from two patients with axonal CMT, we detected a reported recessive variant, p.Arg77Trp, which was herein reclassified as variant with unknown significance. Of the seven CMT4C patients (six females and one male), 2/7 patients developed symptoms at their first decade, and 5/7 patients lost their ambulation around age 50. Scoliosis was observed from more than half (4/7) of these patients, whereas hearing loss is the most common symptom of central nervous system (6/7). No median nerve mononeuropathy was recorded from their family members. We identified recessive variants in SH3TC2 from 1.76% of demyelinating CMT patients. An uncommon gender difference was recognized and the wild spectrum of these variants suggests mutational diversity of SH3TC2 in Japan.

CH 3 NH 3 PbI 3 films prepared by the 2-step method for perovskite solar cells generally have problems of residual unreacted PbI 2 and rough surface structure. Here, we report a new 3-step method, based on the 2-step method with an additional spin-coating of CH 3 NH 3 (I,Br) solution on the CH 3 NH 3 PbI 3 film to scavenge remnant PbI 2 . The 3-step method improved light absorption of the film by converting the residual PbI 2 into CH 3 NH 3 PbI 3−x Br x . Morphological improvements such as a network formation among perovskite grains and a decrease of intergranular voids were also observed. The additional CH 3 NH 3 I spin-coating resulted in the increases of both J SC and V OC , while that of CH 3 NH 3 Br solution showed a slight decrease of J SC and large increase of V OC due to the enlarged bandgaps. The maximum power conversion efficiency was improved from 12.9% (2-step) to 14.4% (3-step). Furthermore, the 3-step cells retained ~ 85% of the original PCE values after storing in air for 700 h, which indicates an improved stability.

BACKGROUND AND PURPOSE The microrchidia family CW-type zinc finger 2 gene (MORC2) was newly identified as a causative gene of Charcot-Marie-Tooth disease (CMT) type 2Z in 2016. We aimed to describe the clinical and mutational spectrum of patients with CMT harboring MORC2 mutations in Japan. METHODS We analyzed samples from 781 unrelated patients clinically diagnosed with CMT using deoxyribonucleic acid microarray or targeted resequencing by next-generation sequencing, and samples from 434 mutation-negative patients were subjected to whole-exome sequencing. We extracted MORC2 variants from these whole-exome sequencing data and classified them according to American College of Medical Genetics standards and guidelines. RESULTS We identified MORC2 variants in 13 patients. As the second most common causative gene of CMT type 2 after MFN2, MORC2 variants were detected in 2.7% of patients with CMT type 2. The mean age of onset was 10.3 ± 8.7 years, and the inheritance pattern was mostly sporadic (11/13 patients, 84.6%). The clinical phenotype was typically length-dependent polyneuropathy, and electrophysiological studies revealed sensory-dominant axonal neuropathy. Mental retardation was identified in 4/13 patients (30.8%). p.Arg190Trp, as a mutational hotspot, was observed in eight unrelated families. We also identified two novel probably pathogenic variants, p.Cys345Tyr and p.Ala369Val, and one novel uncertain significance variant, p.Tyr332Cys. CONCLUSIONS Our study is the largest report of patients harboring MORC2 variants. We revealed a clinical and mutational spectrum of Japanese patients with MORC2 variants. More attention should be paid to cognitive impairment, and the responsible mechanism requires further research for elucidation.

Charcot–Marie–Tooth disease (CMT) constitutes a heterogeneous group affecting motor and sensory neurons in the peripheral nervous system. MFN2 mutations are the most common cause of axonal CMT. We describe the clinical and mutational spectra of CMT patients harboring MFN2 mutations in Japan. We analyzed 1334 unrelated patients with clinically suspected CMT referred by neurological and neuropediatric departments throughout Japan. We conducted mutation screening using a DNA microarray, targeted resequencing, and whole-exome sequencing. We identified pathogenic or likely pathogenic MFN2 variants from 79 CMT patients, comprising 44 heterozygous and 1 compound heterozygous variants. A total of 15 novel variants were detected. An autosomal dominant family history was determined in 43 cases, and the remaining 36 cases were reported as sporadic with no family history. The mean onset age of CMT in these patients was 12 ± 14 (range 0–59) years. We observed neuropathic symptoms in all patients. Some had optic atrophy, vocal cord paralysis, or spasticity. We detected a compound heterozygous MFN2 mutation in a patient with a severe phenotype and the co-occurrence of MFN2 and PMP22 mutations in a patient with an uncommon phenotype. MFN2 is the most frequent causative gene of CMT2 in Japan. We present 15 novel variants and broad clinical and mutational spectra of Japanese MFN2-related CMT patients. Regardless of the onset age and inheritance pattern, MFN2 gene analysis should be performed. Combinations of causative genes should be considered to explain the phenotypic diversity.

The clinical and genetic spectrum of hereditary sensory and autonomic neuropathy (HSAN) is still unknown in Japan. We collected a broad cohort of 33 unrelated patients with predominant sensory and/or autonomic dysfunctions, who were referred to our genetic laboratory. A gene panel sequencing targeting 18 HSAN-related genes was performed using a next-generation sequencing system. A recurrent frame shift mutation in the WNK1/HSN2 gene, c.3237_3238insT (p.Asp1080*), was detected in 5 patients. This mutation was homozygous in 4 cases and of a compound heterozygous genotype in 1 case. Geographic and haplotype analysis of all 5 patients suggested a founder event. In addition, a novel heterozygous nonsense variant, c.2615C>G (p.Ser872*), was identified. All the 5 patients presented with severe sensory and autonomic dysfunctions at birth or during adolescence. In 2 patients, an uncommon phenotype of acute pathological pain presented at ~50 years of age. Here, we present the first founder mutation of WNK1/HSN2, in addition to French Canadian, which accounts for ~15.2% of Japanese patients with HSAN in our cohort. We have also reviewed all previously described mutations in WNK1/HSN2 and reconciled their nomenclature strategy on the basis of the current longest transcript.

Bilateral striatal necrosis (BSN) has many causes and is characterized by unique clinical and neuroradiological features. Herein, we report a clinical and genetic analysis of three BSN cases from two independent Japanese families harboring a mitochondrial DNA (mtDNA) 14459G>A mutation located in a coding region of the NADH dehydrogenase subunit 6 gene. In the first family, two male siblings from non-consanguineous parents exhibited similar phenotypes, with infantile-onset generalized dystonia. A third sporadic case involved a male patient with a comparatively milder phenotype characterized by juvenile-onset mild truncal ataxia and parkinsonism. Cerebral magnetic resonance imaging of these cases revealed abnormal signal intensities along the bilateral putaminal area and enlarged lateral ventricle anterior horns caused by caudate nuclear atrophy, particularly in the sibling pair. The sibling-pair cases shared a homoplasmic 14459G>A mutation, and the sporadic case showed heteroplasmy of the same mutation. Additionally, all three cases harbored the 14605A>G single nucleotide polymorphism, which was previously reported as a rare synonymous variation (4.3%) in a Japanese population. Plasmid sequencing revealed a genetic linkage of these two DNA substitutions, suggesting that the three patients shared a genetic founder. Although our mtDNA analysis was only accessible using leukocytes, clinical severity might be associated with homoplasmy or heteroplasmy. In summary, it is important to evaluate potential mtDNA defects in BSN cases, regardless of familial occurrence.