Publications by authors named "Atsushi Takata"

63 Publications

ATP6V0A1 encoding the a1-subunit of the V0 domain of vacuolar H-ATPases is essential for brain development in humans and mice.

Nat Commun 2021 04 8;12(1):2107. Epub 2021 Apr 8.

Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan.

Vacuolar H-ATPases (V-ATPases) transport protons across cellular membranes to acidify various organelles. ATP6V0A1 encodes the a1-subunit of the V0 domain of V-ATPases, which is strongly expressed in neurons. However, its role in brain development is unknown. Here we report four individuals with developmental and epileptic encephalopathy with ATP6V0A1 variants: two individuals with a de novo missense variant (R741Q) and the other two individuals with biallelic variants comprising one almost complete loss-of-function variant and one missense variant (A512P and N534D). Lysosomal acidification is significantly impaired in cell lines expressing three missense ATP6V0A1 mutants. Homozygous mutant mice harboring human R741Q (Atp6v0a1) and A512P (Atp6v0a1) variants show embryonic lethality and early postnatal mortality, respectively, suggesting that R741Q affects V-ATPase function more severely. Lysosomal dysfunction resulting in cell death, accumulated autophagosomes and lysosomes, reduced mTORC1 signaling and synaptic connectivity, and lowered neurotransmitter contents of synaptic vesicles are observed in the brains of Atp6v0a1 mice. These findings demonstrate the essential roles of ATP6V0A1/Atp6v0a1 in neuronal development in terms of integrity and connectivity of neurons in both humans and mice.
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http://dx.doi.org/10.1038/s41467-021-22389-5DOI Listing
April 2021

Complete sequencing of expanded SAMD12 repeats by long-read sequencing and Cas9-mediated enrichment.

Brain 2021 Apr 1. Epub 2021 Apr 1.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan.

A pentanucleotide TTTCA repeat insertion into a polymorphic TTTTA repeat element in SAMD12 causes benign adult familial myoclonic epilepsy. Although the precise determination of the entire SAMD12 repeat sequence is important for molecular diagnosis and research, obtaining this sequence remains challenging when using conventional genomic/genetic methods, and even short-read and long-read next-generation sequencing technologies have been insufficient. Incomplete information regarding expanded repeat sequences may hamper our understanding of the pathogenic roles played by varying numbers of repeat units, genotype-phenotype correlations, and mutational mechanisms. Here, we report a new approach for the precise determination of the entire expanded repeat sequence and present a workflow designed to improve the diagnostic rates in various repeat expansion diseases.
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http://dx.doi.org/10.1093/brain/awab021DOI Listing
April 2021

Combination of dirty mass volume and APACHE II score predicts mortality in patients with colorectal perforation.

World J Emerg Surg 2021 Mar 30;16(1):17. Epub 2021 Mar 30.

Department of Surgery, Yoshinogawa Medical Center, 120 Nishichiejima, Yoshinogawa City, Tokushima, 776-8511, Japan.

Background: "Dirty mass" is a specific computed tomography (CT) finding that is seen frequently in colorectal perforation. The prognostic significance of this finding for mortality is unclear.

Methods: Fifty-eight consecutive patients with colorectal perforation who underwent emergency surgery were retrospectively reviewed in the study. Dirty mass identified on multi-detector row CT (MDCT) was 3D-reconstructed and its volume was calculated using Ziostation software. Dirty mass volume and other clinical characteristics were compared between survivor (n = 45) and mortality groups (n = 13) to identify predictive factors for mortality. Mann-Whitney U test and Χ test were used in univariate analysis and logistic regression analysis was used in multivariate analysis.

Results: Dirty mass was identified in 36/58 patients (62.1%) and located next to perforated colorectum in all cases. Receiver-operating characteristic (ROC) curve analysis identified the highest peak at 96.3 cm, with sensitivity of 0.643 and specificity of 0.864. Univariate analysis revealed dirty mass volume, acute disseminated intravascular coagulation (DIC) score, acute physiology and chronic health evaluation II (APACHE II) score, and sequential organ failure assessment (SOFA) score as prognostic markers for mortality (p<0.01). Multivariate analysis revealed dirty mass volume and APACHE II score as independent prognostic indicators for mortality. Mortality was stratified by dividing patients into four groups according to dirty mass volume and APACHE II score.

Conclusions: The combination of dirty mass volume and APACHE II score could stratify the postoperative mortality risk in patients with colorectal perforation. According to the risk stratification, surgeons might be able to decide the surgical procedures and intensity of postoperative management.
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http://dx.doi.org/10.1186/s13017-021-00359-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8008772PMC
March 2021

De novo ATP1A3 variants cause polymicrogyria.

Sci Adv 2021 Mar 24;7(13). Epub 2021 Mar 24.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan.

Polymicrogyria is a common malformation of cortical development whose etiology remains elusive. We conducted whole-exome sequencing for 124 patients with polymicrogyria and identified de novo variants in eight patients. Mutated causes functional brain diseases, including alternating hemiplegia of childhood (AHC), rapid-onset dystonia parkinsonism (RDP), and cerebellar ataxia, areflexia, pes cavus, optic nerve atrophy, and sensorineural deafness (CAPOS). However, our patients showed no clinical features of AHC, RDP, or CAPOS and had a completely different phenotype: a severe form of polymicrogyria with epilepsy and developmental delay. Detected variants had different locations in and different functional properties compared with AHC-, RDP-, or CAPOS-associated variants. In the developing cerebral cortex of mice, radial neuronal migration was impaired in neurons overexpressing the variant of the most severe patients, suggesting that this variant is involved in cortical malformation pathogenesis. We propose a previously unidentified category of polymicrogyria associated with abnormalities.
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http://dx.doi.org/10.1126/sciadv.abd2368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7990330PMC
March 2021

Hemizygous FLNA variant in West syndrome without periventricular nodular heterotopia.

Hum Genome Var 2020 Dec 3;7(1):43. Epub 2020 Dec 3.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa, Yokohama, 236-0004, Japan.

Pathogenic FLNA variants can be identified in patients with seizures accompanied by periventricular nodular heterotopia (PVNH). It is unusual to find FLNA aberrations in epileptic patients without PVNH on brain imaging. We report a boy with cryptogenic West syndrome followed by refractory seizures and psychomotor delay. We performed whole-exome sequencing and identified a de novo missense variant in FLNA. It is noteworthy that this patient showed no PVNH. As no other pathogenic variants were found in epilepsy-related genes, this FLNA variant likely caused West syndrome but with no PVNH.
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http://dx.doi.org/10.1038/s41439-020-00131-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713383PMC
December 2020

Whole exome sequencing of fetal structural anomalies detected by ultrasonography.

J Hum Genet 2020 Nov 3. Epub 2020 Nov 3.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

The objective of this study was to evaluate the efficacy of whole exome sequencing (WES) for the genetic diagnosis of cases presenting with fetal structural anomalies detected by ultrasonography. WES was performed on 19 cases with prenatal structural anomalies. Genomic DNA was extracted from umbilical cords or umbilical blood obtained shortly after birth. WES data were analyzed on prenatal phenotypes alone, and the data were re-analyzed after information regarding the postnatal phenotype was obtained. Based solely on the fetal phenotype, pathogenic, or likely pathogenic, single nucleotide variants were identified in 5 of 19 (26.3%) cases. Moreover, we detected trisomy 21 in two cases by WES-based copy number variation analysis. The overall diagnostic rate was 36.8% (7/19). They were all compatible with respective fetal structural anomalies. By referring to postnatal phenotype information, another candidate variant was identified by a postnatal clinical feature that was not detected in prenatal screening. As detailed phenotyping is desirable for better diagnostic rates in WES analysis, we should be aware that fetal phenotype is a useful, but sometimes limited source of information for comprehensive genetic analysis. It is important to amass more data of genotype-phenotype correlations, especially to appropriately assess the validity of WES in prenatal settings.
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http://dx.doi.org/10.1038/s10038-020-00869-8DOI Listing
November 2020

Efficient detection of copy-number variations using exome data: Batch- and sex-based analyses.

Hum Mutat 2021 Jan 11;42(1):50-65. Epub 2020 Nov 11.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

Many algorithms to detect copy number variations (CNVs) using exome sequencing (ES) data have been reported and evaluated on their sensitivity and specificity, reproducibility, and precision. However, operational optimization of such algorithms for a better performance has not been fully addressed. ES of 1199 samples including 763 patients with different disease profiles was performed. ES data were analyzed to detect CNVs by both the eXome Hidden Markov Model (XHMM) and modified Nord's method. To efficiently detect rare CNVs, we aimed to decrease sequencing biases by analyzing, at the same time, the data of all unrelated samples sequenced in the same flow cell as a batch, and to eliminate sex effects of X-linked CNVs by analyzing female and male sequences separately. We also applied several filtering steps for more efficient CNV selection. The average number of CNVs detected in one sample was <5. This optimization together with targeted CNV analysis by Nord's method identified pathogenic/likely pathogenic CNVs in 34 patients (4.5%, 34/763). In particular, among 142 patients with epilepsy, the current protocol detected clinically relevant CNVs in 19 (13.4%) patients, whereas the previous protocol identified them in only 14 (9.9%) patients. Thus, this batch-based XHMM analysis efficiently selected rare pathogenic CNVs in genetic diseases.
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http://dx.doi.org/10.1002/humu.24129DOI Listing
January 2021

De novo variants in CELF2 that disrupt the nuclear localization signal cause developmental and epileptic encephalopathy.

Hum Mutat 2021 Jan 10;42(1):66-76. Epub 2020 Nov 10.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.

We report heterozygous CELF2 (NM_006561.3) variants in five unrelated individuals: Individuals 1-4 exhibited developmental and epileptic encephalopathy (DEE) and Individual 5 had intellectual disability and autistic features. CELF2 encodes a nucleocytoplasmic shuttling RNA-binding protein that has multiple roles in RNA processing and is involved in the embryonic development of the central nervous system and heart. Whole-exome sequencing identified the following CELF2 variants: two missense variants [c.1558C>T:p.(Pro520Ser) in unrelated Individuals 1 and 2, and c.1516C>G:p.(Arg506Gly) in Individual 3], one frameshift variant in Individual 4 that removed the last amino acid of CELF2 c.1562dup:p.(Tyr521Ter), possibly resulting in escape from nonsense-mediated mRNA decay (NMD), and one canonical splice site variant, c.272-1G>C in Individual 5, also probably leading to NMD. The identified variants in Individuals 1, 2, 4, and 5 were de novo, while the variant in Individual 3 was inherited from her mosaic mother. Notably, all identified variants, except for c.272-1G>C, were clustered within 20 amino acid residues of the C-terminus, which might be a nuclear localization signal. We demonstrated the extranuclear mislocalization of mutant CELF2 protein in cells transfected with mutant CELF2 complementary DNA plasmids. Our findings indicate that CELF2 variants that disrupt its nuclear localization are associated with DEE.
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http://dx.doi.org/10.1002/humu.24130DOI Listing
January 2021

Novel EXOSC9 variants cause pontocerebellar hypoplasia type 1D with spinal motor neuronopathy and cerebellar atrophy.

J Hum Genet 2021 Apr 10;66(4):401-407. Epub 2020 Oct 10.

Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.

Pontocerebellar hypoplasia (PCH) is currently classified into 13 subgroups and many gene variants associated with PCH have been identified by next generation sequencing. PCH type 1 is a rare heterogeneous neurodegenerative disorder. The clinical presentation includes early-onset severe developmental delay, progressive motor neuronopathy, and cerebellar and pontine atrophy. Recently two variants in the EXOSC9 gene (MIM: 606180), NM_001034194.1: c.41T>C (p.Leu14Pro) and c.481C>T (p.Arg161*) were identified in four unrelated patients with PCH type 1D (PCH1D) (MIM: 618065). EXOSC9 encodes a component of the exosome complex, which is essential for correct processing and degradation of RNA. We report here two PCH1D families with biallelic EXOSC9 variants: c.239T>G (p.Leu80Arg) and c.484dupA (p.Arg162Lysfs*3) in one family and c.151G>C (p.Gly51Arg) in the other family. Although the patients studied here showed similar clinical features as previously described for PCH1D, relatively greater intellectual development (although still highly restricted) and normal pontine structure were recognized. Our findings expand the clinical consequences of biallelic EXOSC9 variants.
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http://dx.doi.org/10.1038/s10038-020-00853-2DOI Listing
April 2021

The identification of two pathogenic variants in a family with mild and severe forms of developmental delay.

J Hum Genet 2021 Apr 9;66(4):445-448. Epub 2020 Oct 9.

Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, P.O. Box, 14115-331, Tehran, Iran.

Intellectual disability (ID) accounts for 1% of the general population, and it is caused by the interplay between the genetic and/or environmental factors. The genetic components responsible for the development of ID are highly heterogeneous, and the phenotype and severity of the disease vary in patients even if they have an identical pathological variant and/or belong to the same family. Herein, we reported two male siblings with ID in an Iranian family. By means of the whole-exome sequencing method, elder brother affected by a moderate form of ID exhibited a de novo missense variant in the KCNQ3 gene, while another sibling afflicted with a severe form of the disease exhibited a de novo in-frame deletion in the UBE3A gene. Both variants have been previously ascribed to similar clinical phenotypes. In addition, a genetic variant in the KCNQ3 gene was transmitted to his son, who had a mild form of ID. To our knowledge, all individuals with KCNQ3-related developmental delay show de novo variants in the KCNQ3 gene. Thus, this familial case exhibit milder phenotype that might extend the clinical spectrum of KCNQ3 pathogenic variants. In addition, the current report highlights the significance of the clinical evaluation and non-biased assessment of the genetic analysis.
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http://dx.doi.org/10.1038/s10038-020-0809-8DOI Listing
April 2021

Prenatal clinical manifestations in individuals with variants.

J Med Genet 2020 Jul 30. Epub 2020 Jul 30.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan

Background: Variants in the type IV collagen gene () cause early-onset cerebrovascular diseases. Most individuals are diagnosed postnatally, and the prenatal features of individuals with variants remain unclear.

Methods: We examined in 218 individuals with suspected /2-related brain defects. Among those arising from variants, we focused on individuals showing prenatal abnormal ultrasound findings and validated their prenatal and postnatal clinical features in detail.

Results: Pathogenic variants were detected in 56 individuals (n=56/218, 25.7%) showing porencephaly (n=29), schizencephaly (n=12) and others (n=15). Thirty-four variants occurred de novo (n=34/56, 60.7%). Foetal information was available in 47 of 56 individuals, 32 of whom (n=32/47, 68.1%) had one or more foetal abnormalities. The median gestational age at the detection of initial prenatal abnormal features was 31 weeks of gestation. Only 14 individuals had specific prenatal findings that were strongly suggestive of features associated with variants. Foetal ventriculomegaly was the most common initial feature (n=20/32, 62.5%). Posterior fossa abnormalities, including Dandy-Walker malformation, were observed prenatally in four individuals. Regarding extrabrain features, foetal growth restriction was present in 16 individuals, including eight individuals with comorbid ventriculomegaly.

Conclusions: Prenatal observation of ventriculomegaly with comorbid foetal growth restriction should prompt a thorough ultrasound examination and gene testing should be considered when pathogenic variants are strongly suspected.
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http://dx.doi.org/10.1136/jmedgenet-2020-106896DOI Listing
July 2020

De Novo Truncating Variants in the Last Exon of SEMA6B Cause Progressive Myoclonic Epilepsy.

Am J Hum Genet 2020 04 12;106(4):549-558. Epub 2020 Mar 12.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan. Electronic address:

De novo variants (DNVs) cause many genetic diseases. When DNVs are examined in the whole coding regions of genes in next-generation sequencing analyses, pathogenic DNVs often cluster in a specific region. One such region is the last exon and the last 50 bp of the penultimate exon, where truncating DNVs cause escape from nonsense-mediated mRNA decay [NMD(-) region]. Such variants can have dominant-negative or gain-of-function effects. Here, we first developed a resource of rates of truncating DNVs in NMD(-) regions under the null model of DNVs. Utilizing this resource, we performed enrichment analysis of truncating DNVs in NMD(-) regions in 346 developmental and epileptic encephalopathy (DEE) trios. We observed statistically significant enrichment of truncating DNVs in semaphorin 6B (SEMA6B) (p value: 2.8 × 10; exome-wide threshold: 2.5 × 10). The initial analysis of the 346 individuals and additional screening of 1,406 and 4,293 independent individuals affected by DEE and developmental disorders collectively identified four truncating DNVs in the SEMA6B NMD(-) region in five individuals who came from unrelated families (p value: 1.9 × 10) and consistently showed progressive myoclonic epilepsy. RNA analysis of lymphoblastoid cells established from an affected individual showed that the mutant allele escaped NMD, indicating stable production of the truncated protein. Importantly, heterozygous truncating variants in the NMD(+) region of SEMA6B are observed in general populations, and SEMA6B is most likely loss-of-function tolerant. Zebrafish expressing truncating variants in the NMD(-) region of SEMA6B orthologs displayed defective development of brain neurons and enhanced pentylenetetrazole-induced seizure behavior. In summary, we show that truncating DNVs in the final exon of SEMA6B cause progressive myoclonic epilepsy.
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http://dx.doi.org/10.1016/j.ajhg.2020.02.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118575PMC
April 2020

Gain-of-Function MN1 Truncation Variants Cause a Recognizable Syndrome with Craniofacial and Brain Abnormalities.

Am J Hum Genet 2020 01 12;106(1):13-25. Epub 2019 Dec 12.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan. Electronic address:

MN1 was originally identified as a tumor-suppressor gene. Knockout mouse studies have suggested that Mn1 is associated with craniofacial development. However, no MN1-related phenotypes have been established in humans. Here, we report on three individuals who have de novo MN1 variants that lead to a protein lacking the carboxyl (C) terminus and who presented with severe developmental delay, craniofacial abnormalities with specific facial features, and structural abnormalities in the brain. An in vitro study revealed that the deletion of the C-terminal region led to increased protein stability, an inhibitory effect on cell proliferation, and enhanced MN1 aggregation in nuclei compared to what occurred in the wild type, suggesting that a gain-of-function mechanism is involved in this disease. Considering that C-terminal deletion increases the fraction of intrinsically disordered regions of MN1, it is possible that altered phase separation could be involved in the mechanism underlying the disease. Our data indicate that MN1 participates in transcriptional regulation of target genes through interaction with the transcription factors PBX1, PKNOX1, and ZBTB24 and that mutant MN1 impairs the binding with ZBTB24 and RING1, which is an E3 ubiquitin ligase. On the basis of our findings, we propose the model that C-terminal deletion interferes with MN1's interaction molecules related to the ubiquitin-mediated proteasome pathway, including RING1, and increases the amount of the mutant protein; this increase leads to the dysregulation of MN1 target genes by inhibiting rapid MN1 protein turnover.
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http://dx.doi.org/10.1016/j.ajhg.2019.11.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7042485PMC
January 2020

Recurrent NUS1 canonical splice donor site mutation in two unrelated individuals with epilepsy, myoclonus, ataxia and scoliosis - a case report.

BMC Neurol 2019 Oct 27;19(1):253. Epub 2019 Oct 27.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa, Yokohama, 236-0004, Japan.

Background: We encountered two unrelated individuals suffering from neurological disorders, including epilepsy and scoliosis.

Case Presentation: Whole-exome sequencing identified the same recurrent, de novo, pathogenic variant in NUS1 [NM_138459.4:c.691 + 1C > A] in both individuals. This variant is located in the conserved cis-prenyltransferase domain of the nuclear undecaprenyl pyrophosphate synthase 1 gene (NUS1), which encodes the Nogo-B receptor, an essential catalyst for protein glycosylation. This variant was confirmed to create a new splice donor site, resulting in aberrant RNA splicing resulting in a 91-bp deletion in exon 3 in both individuals. The mutant mRNA was partially degraded by nonsense mediated mRNA decay. To date, only four de novo variants and one homozygous variant have been reported in NUS1, which cause developmental and epileptic encephalopathy, early onset Parkinson's disease, and a congenital disorder of glycosylation. Seven patients, including our two patients, have presented with epileptic seizures and intellectual disabilities.

Conclusions: Our study strongly supports the finding that this recurrent, de novo, variant in NUS1 causes developmental and epileptic encephalopathy with involuntary movement, ataxia and scoliosis.
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http://dx.doi.org/10.1186/s12883-019-1489-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6815447PMC
October 2019

Recapitulation and Reversal of Schizophrenia-Related Phenotypes in Setd1a-Deficient Mice.

Neuron 2019 11 9;104(3):471-487.e12. Epub 2019 Oct 9.

Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; Mortimer B. Zuckerman Mind Brain and Behavior Institute Columbia University, New York, NY 10027, USA; Department of Neuroscience, Columbia University, New York, NY 10032, USA. Electronic address:

SETD1A, a lysine-methyltransferase, is a key schizophrenia susceptibility gene. Mice carrying a heterozygous loss-of-function mutation of the orthologous gene exhibit alterations in axonal branching and cortical synaptic dynamics accompanied by working memory deficits. We show that Setd1a binds both promoters and enhancers with a striking overlap between Setd1a and Mef2 on enhancers. Setd1a targets are highly expressed in pyramidal neurons and display a complex pattern of transcriptional up- and downregulations shaped by presumed opposing functions of Setd1a on promoters and Mef2-bound enhancers. Notably, evolutionarily conserved Setd1a targets are associated with neuropsychiatric genetic risk burden. Reinstating Setd1a expression in adulthood rescues cognitive deficits. Finally, we identify LSD1 as a major counteracting demethylase for Setd1a and show that its pharmacological antagonism results in a full rescue of the behavioral and morphological deficits in Setd1a-deficient mice. Our findings advance understanding of how SETD1A mutations predispose to schizophrenia (SCZ) and point to novel therapeutic interventions.
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http://dx.doi.org/10.1016/j.neuron.2019.09.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7010348PMC
November 2019

Genetic abnormalities in a large cohort of Coffin-Siris syndrome patients.

J Hum Genet 2019 Dec 17;64(12):1173-1186. Epub 2019 Sep 17.

Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.

Coffin-Siris syndrome (CSS, MIM#135900) is a congenital disorder characterized by coarse facial features, intellectual disability, and hypoplasia of the fifth digit and nails. Pathogenic variants for CSS have been found in genes encoding proteins in the BAF (BRG1-associated factor) chromatin-remodeling complex. To date, more than 150 CSS patients with pathogenic variants in nine BAF-related genes have been reported. We previously reported 71 patients of whom 39 had pathogenic variants. Since then, we have recruited an additional 182 CSS-suspected patients. We performed comprehensive genetic analysis on these 182 patients and on the previously unresolved 32 patients, targeting pathogenic single nucleotide variants, short insertions/deletions and copy number variations (CNVs). We confirmed 78 pathogenic variations in 78 patients. Pathogenic variations in ARID1B, SMARCB1, SMARCA4, ARID1A, SOX11, SMARCE1, and PHF6 were identified in 48, 8, 7, 6, 4, 1, and 1 patients, respectively. In addition, we found three CNVs including SMARCA2. Of particular note, we found a partial deletion of SMARCB1 in one CSS patient and we thoroughly investigated the resulting abnormal transcripts.
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http://dx.doi.org/10.1038/s10038-019-0667-4DOI Listing
December 2019

Comparison of mitochondrial DNA variants detection using short- and long-read sequencing.

J Hum Genet 2019 Nov 13;64(11):1107-1116. Epub 2019 Aug 13.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.

The recent advent of long-read sequencing technologies is expected to provide reasonable answers to genetic challenges unresolvable by short-read sequencing, primarily the inability to accurately study structural variations, copy number variations, and homologous repeats in complex parts of the genome. However, long-read sequencing comes along with higher rates of random short deletions and insertions, and single nucleotide errors. The relatively higher sequencing accuracy of short-read sequencing has kept it as the first choice of screening for single nucleotide variants and short deletions and insertions. Albeit, short-read sequencing still suffers from systematic errors that tend to occur at specific positions where a high depth of reads is not always capable to correct for these errors. In this study, we compared the genotyping of mitochondrial DNA variants in three samples using PacBio's Sequel (Pacific Biosciences Inc., Menlo Park, CA, USA) long-read sequencing and illumina's HiSeqX10 (illumine Inc., San Diego, CA, USA) short-read sequencing data. We concluded that, despite the differences in the type and frequency of errors in the long-reads sequencing, its accuracy is still comparable to that of short-reads for genotyping short nuclear variants; due to the randomness of errors in long reads, a lower coverage, around 37 reads, can be sufficient to correct for these random errors.
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http://dx.doi.org/10.1038/s10038-019-0654-9DOI Listing
November 2019

Comprehensive genetic analysis of 57 families with clinically suspected Cornelia de Lange syndrome.

J Hum Genet 2019 Oct 23;64(10):967-978. Epub 2019 Jul 23.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

Cornelia de Lange syndrome (CdLS) is a rare multisystem disorder with specific dysmorphic features. Pathogenic genetic variants encoding cohesion complex subunits and interacting proteins (e.g., NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major causes of CdLS. However, there are many clinically diagnosed cases of CdLS without pathogenic variants in these genes. To identify further genetic causes of CdLS, we performed whole-exome sequencing in 57 CdLS families, systematically evaluating both single nucleotides variants (SNVs) and copy number variations (CNVs). We identified pathogenic genetic changes in 36 out of 57 (63.2 %) families, including 32 SNVs and four CNVs. Two known CdLS genes, NIPBL and SMC1A, were mutated in 23 and two cases, respectively. Among the remaining 32 individuals, four genes (ANKRD11, EP300, KMT2A, and SETD5) each harbored a pathogenic variant in a single individual. These variants are known to be involved in CdLS-like. Furthermore, pathogenic CNVs were detected in NIPBL, MED13L, and EHMT1, along with pathogenic SNVs in ZMYND11, MED13L, and PHIP. These three latter genes were involved in diseases other than CdLS and CdLS-like. Systematic clinical evaluation of all patients using a recently proposed clinical scoring system showed that ZMYND11, MED13L, and PHIP abnormality may cause CdLS or CdLS-like.
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http://dx.doi.org/10.1038/s10038-019-0643-zDOI Listing
October 2019

Hemorrhagic stroke and renovascular hypertension with Grange syndrome arising from a novel pathogenic variant in YY1AP1.

J Hum Genet 2019 Sep 4;64(9):885-890. Epub 2019 Jul 4.

Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan.

Pediatric hypertension can cause hypertensive emergencies, including hemorrhagic stroke, contributing to rare but serious childhood morbidity and mortality. Renovascular hypertension (RVH) is one of the major causes of secondary hypertension in children. Grange syndrome (MIM#602531) is a rare disease characterized by multiple stenosis or occlusion of the renal, abdominal, coronary, and cerebral arteries, which can cause phenotypes of RVH and fibromuscular dysplasia (MIM#135580). We report the case of a 7-year-old girl with Grange syndrome who showed RVH and multiple seizure episodes. At 1 year of age, she experienced seizures and sequential hemiparesis caused by a left thalamic hemorrhage without cerebral vascular anomalies. Chronic hypertension was observed, and abdominal computed tomography angiography showed characteristic bilateral renal artery stenosis. Whole-exome sequencing revealed a novel homozygous pathogenic variant in the YY1AP1 gene (NM_001198903.1: c.1169del: p.Lys390Argfs*12). Biallelic YY1AP1 mutations are known to cause Grange syndrome. Unlike previously reported patients, our patient presented with intracerebral hemorrhagic stroke without anomalous brain artery or bone fragility. The phenotype in our patient may help better understand this ultra-rare syndrome. Grange syndrome should be considered in patients presenting with childhood-onset hypertension and/or hemorrhagic stroke for early clinical intervention.
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http://dx.doi.org/10.1038/s10038-019-0626-0DOI Listing
September 2019

Primary immunodeficiency with chronic enteropathy and developmental delay in a boy arising from a novel homozygous RIPK1 variant.

J Hum Genet 2019 Sep 18;64(9):955-960. Epub 2019 Jun 18.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

Identification of genetic causes of primary monogenic immunodeficiencies would strengthen the current understanding of their immunopathology. Pathogenic variants in genes in association with tumor necrosis factor α (TNFα) signaling, including OTULIN, TNFAIP3, RBCK1, and RNF31 cause human congenital autoinflammatory diseases with/without immunodeficiency. RIPK1, encoding a receptor interacting serine/threonine kinase 1, is present in protein complexes mediating signal transduction including TNF receptor 1. Biallelic loss-of-function variants in RIPK1 were recently reported in individuals with primary immunodeficiency with intestinal bowel disease and arthritis. Here, we report a novel homozygous RIPK1 variant in a boy with immunodeficiency and chronic enteropathy. Our patient exhibited severe motor delay and mild intellectual disability, which were previously unknown. The present results are expected to deepen the current understanding of clinical features based on RIPK1 abnormalities.
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http://dx.doi.org/10.1038/s10038-019-0631-3DOI Listing
September 2019

Pathogenic variants of , , and associated with hypothalamic hamartoma.

Neurology 2019 07 13;93(3):e237-e251. Epub 2019 Jun 13.

From the Departments of Human Genetics (A.F., S. Mitsuhashi, T.M., A.T., S. Miyatake, N. Miyake, N. Matsumoto) and Neurosurgery (M.S.), Yokohama City University Graduate School of Medicine; Departments of Functional Neurosurgery (T.H., H. Shirozu, H.M., M.F., S.K.) and Child Neurology (J.T.), Epilepsy Center, National Hospital Organization Nishiniigata Chuo Hospital Niigata, Japan; Department of Pediatrics and Neurology (M.S.), Wayne State University, Children's Hospital of Michigan, Detroit Medical Center; Department of Pediatrics (M.K.), Showa University School of Medicine, Tokyo; Department of Biochemistry (M.N., H. Saitsu), Hamamatsu University School of Medicine; and Clinical Research Institute (Y.T.), Kanagawa Children's Medical Center, Yokohama, Japan.

Objective: Intensive genetic analysis was performed to reveal comprehensive molecular insights into hypothalamic hamartoma (HH).

Methods: Thirty-eight individuals with HH were investigated by whole exome sequencing, target capture-based deep sequencing, or single nucleotide polymorphism (SNP) array using DNA extracted from blood leukocytes or HH samples.

Results: We identified a germline variant of , which encodes a ciliary protein, and 2 somatic variants of , which forms part of the RAS/mitogen-activated protein kinase (MAPK) pathway, as well as variants in known genes associated with HH. An SNP array identified (among 3 patients) one germline copy-neutral loss of heterozygosity (cnLOH) at 6p22.3-p21.31 and 2 somatic cnLOH; one at 11q12.2-q25 that included , which encodes a ciliary motor protein, and the other at 17p13.3-p11.2. A germline heterozygous variant and an identical somatic variant of arising from cnLOH at 11q12.2-q25 were confirmed in one patient (whose HH tissue, therefore, contains biallelic variants of ). Furthermore, a combination of a germline and a somatic variant was detected in another patient.

Conclusions: Overall, our cohort identified germline/somatic alterations in 34% (13/38) of patients with HH. Disruption of the Shh signaling pathway associated with cilia or the RAS/MAPK pathway may lead to the development of HH.
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http://dx.doi.org/10.1212/WNL.0000000000007774DOI Listing
July 2019

Comprehensive analysis of coding variants highlights genetic complexity in developmental and epileptic encephalopathy.

Nat Commun 2019 06 7;10(1):2506. Epub 2019 Jun 7.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.

Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes. Importantly, enrichment of dURVs in non-EE/DEE genes is significant, even in the subset of cases with diagnostic dURVs (P = 0.000215), suggesting oligogenic contribution of non-EE/DEE gene dURVs. Gene-based analysis identifies exome-wide significant (P = 2.04 × 10) enrichment of damaging de novo mutations in NF1, a gene primarily linked to neurofibromatosis, in infantile spasm. Together with accumulating evidence for roles of oligogenic or modifier variants in severe neurodevelopmental disorders, our results highlight genetic complexity in EE/DEE, and indicate that EE/DEE is not an aggregate of simple Mendelian disorders.
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http://dx.doi.org/10.1038/s41467-019-10482-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6555845PMC
June 2019

Haploinsufficiency of A20 caused by a novel nonsense variant or entire deletion of TNFAIP3 is clinically distinct from Behçet's disease.

Arthritis Res Ther 2019 06 4;21(1):137. Epub 2019 Jun 4.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.

Background: Haploinsufficiency of A20 (HA20) is caused by loss-of-function TNFAIP3 variants. Phenotypic and genetic features of HA20 remain uncertain; therefore, the clinical distinction between HA20 and Behçet's disease (BD) requires clarification.

Methods: We have collected 12 Japanese BD-like families. Probands of these families were analyzed by whole exome sequencing (WES) and subsequent Sanger sequencing. Clinical features were compared between 54 HA20 patients (including previously reported and new cases) and 520 Japanese BD patients.

Results: We identified c.1434C>A:p.(Cys478*) in one family and a 236 kb deletion at 6q23.3 containing TNFAIP3 in another family. Four HA20 patients in the two families presented with childhood-onset recurrent oral and genital ulcers and were initially diagnosed and treated as BD. Consistent with the clinical features of HA20, recurrent, refractory fever attacks (three of four patients), and digestive ulcers (two of the four patients) were observed. A comparison of clinical features between HA20 patients and cohorts of BD patients revealed several critical features specific to HA20. These were early-onset, familial occurrence, recurrent fever attacks, gastrointestinal involvement, and infrequent ocular involvement.

Conclusions: We identified a novel nonsense variant and deletion of the entire TNFAIP3 gene in two unrelated Japanese HA20 families. Genetic screening of TNFAIP3 should be considered for familial BD-like patients with early-onset recurrent fevers.
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http://dx.doi.org/10.1186/s13075-019-1928-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6549368PMC
June 2019

A novel de novo frameshift variant in SETD1B causes epilepsy.

J Hum Genet 2019 Aug 20;64(8):821-827. Epub 2019 May 20.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.

We identified a de novo frameshift variant (NM_015048.1:c.5644_5647del:p.(Ile1882Serfs*118)) in the last exon of SETD1B in a Japanese patient with autistic behavior, developmental delay, intellectual disability, and myoclonic seizures. This variant is predicted to disrupt a well-conserved carboxyl-terminus SET domain, which is known to modulate gene activities and/or chromatin structure. Previously, two de novo missense mutations in SETD1B were reported in two patients with epilepsy. All three patients including the current patient share similar clinical features. Herein, we report a first epilepsy patient with a frameshift variant in SETD1B, emphasizing a possible pathomechanistic association of SETD1B abnormality with neurodevelopmental delay with epilepsy.
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http://dx.doi.org/10.1038/s10038-019-0617-1DOI Listing
August 2019

MYRF haploinsufficiency causes 46,XY and 46,XX disorders of sex development: bioinformatics consideration.

Hum Mol Genet 2019 07;28(14):2319-2329

Department of Human Genetics.

Disorders of sex development (DSDs) are defined as congenital conditions in which chromosomal, gonadal or anatomical sex is atypical. In many DSD cases, genetic causes remain to be elucidated. Here, we performed a case-control exome sequencing study comparing gene-based burdens of rare damaging variants between 26 DSD cases and 2625 controls. We found exome-wide significant enrichment of rare heterozygous truncating variants in the MYRF gene encoding myelin regulatory factor, a transcription factor essential for oligodendrocyte development. All three variants occurred de novo. We identified an additional 46,XY DSD case of a de novo damaging missense variant in an independent cohort. The clinical symptoms included hypoplasia of Müllerian derivatives and ovaries in 46,XX DSD patients, defective development of Sertoli and Leydig cells in 46,XY DSD patients and congenital diaphragmatic hernia in one 46,XY DSD patient. As all of these cells and tissues are or partly consist of coelomic epithelium (CE)-derived cells (CEDC) and CEDC developed from CE via proliferaiton and migration, MYRF might be related to these processes. Consistent with this hypothesis, single-cell RNA sequencing of foetal gonads revealed high expression of MYRF in CE and CEDC. Reanalysis of public chromatin immunoprecipitation sequencing data for rat Myrf showed that genes regulating proliferation and migration were enriched among putative target genes of Myrf. These results suggested that MYRF is a novel causative gene of 46,XY and 46,XX DSD and MYRF is a transcription factor regulating CD and/or CEDC proliferation and migration, which is essential for development of multiple organs.
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http://dx.doi.org/10.1093/hmg/ddz066DOI Listing
July 2019

Genetic landscape of Rett syndrome-like phenotypes revealed by whole exome sequencing.

J Med Genet 2019 06 6;56(6):396-407. Epub 2019 Mar 6.

Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan.

Background: Rett syndrome (RTT) is a characteristic neurological disease presenting with regressive loss of neurodevelopmental milestones. Typical RTT is generally caused by abnormality of methyl-CpG binding protein 2 (). Our objective to investigate the genetic landscape of -negative typical/atypical RTT and RTT-like phenotypes using whole exome sequencing (WES).

Methods: We performed WES on 77 -negative patients either with typical RTT (n=11), atypical RTT (n=22) or RTT-like phenotypes (n=44) incompatible with the RTT criteria.

Results: Pathogenic or likely pathogenic single-nucleotide variants in 28 known genes were found in 39 of 77 (50.6%) patients. WES-based CNV analysis revealed pathogenic deletions involving six known genes (including ) in 8 of 77 (10.4%) patients. Overall, diagnostic yield was 47 of 77 (61.0 %). Furthermore, strong candidate variants were found in four novel genes: a de novo variant in each of ATPase H transporting V0 subunit A1 (), ubiquitin-specific peptidase 8 () and microtubule-associated serine/threonine kinase 3 (), as well as biallelic variants in nuclear receptor corepressor 2 ().

Conclusions: Our study provides a new landscape including additional genetic variants contributing to RTT-like phenotypes, highlighting the importance of comprehensive genetic analysis.
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http://dx.doi.org/10.1136/jmedgenet-2018-105775DOI Listing
June 2019

RALA mutation in a patient with autism spectrum disorder and Noonan syndrome-like phenotype.

Congenit Anom (Kyoto) 2019 Nov 8;59(6):195-196. Epub 2019 Mar 8.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

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http://dx.doi.org/10.1111/cga.12327DOI Listing
November 2019

The protective effect of epigallocatechin 3-gallate on mouse pancreatic islets via the Nrf2 pathway.

Surg Today 2019 Jun 7;49(6):536-545. Epub 2019 Feb 7.

Department of Surgery, Graduate School of Biomedical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, 770-8503, Tokushima, Japan.

Purpose: Epigallocatechin 3-gallate (EGCG), a green tea polyphenol, has been shown to have anti-oxidant and anti-inflammatory effects in vitro and in vivo. The aim of this study was to investigate the effects and mechanism of EGCG on isolated pancreatic islets as pre-conditioning for pancreatic islet transplantation.

Methods: The pancreatic islets were divided into two groups: an islet culture medium group (control) and an islet culture medium with EGCG (100 µM) group. We investigated the islet viability, Nrf2 expression, reactive oxygen species (ROS) production, and heme oxygenase-1 (HO-1) mRNA. Five hundred islet equivalents after 12 h of culture for the EGCG 100 µM and control group were transplanted under the kidney capsule of streptozotocin-induced diabetic ICR mice.

Results: The cell viability and insulin secretion ability in the EGCG group were preserved, and the nuclear translocation of Nrf2 was increased in the EGCG group (p < 0.01). While the HO-1 mRNA levels were also higher in the EGCG group than in the control group (p < 0.05), the ROS production was lower (p < 0.01). An in vivo functional assessment showed that the blood glucose level had decreased in the EGCG group after transplantation (p < 0.01).

Conclusion: EGCG protects the viability and function of islets by suppressing ROS production via the Nrf2 pathway.
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http://dx.doi.org/10.1007/s00595-019-1761-0DOI Listing
June 2019

A novel homozygous truncating variant of NECAP1 in early infantile epileptic encephalopathy: the second case report of EIEE21.

J Hum Genet 2019 Apr 9;64(4):347-350. Epub 2019 Jan 9.

Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan.

We report the second case of early infantile epileptic encephalopathy (EIEE) arising from a homozygous truncating variant of NECAP1. The boy developed infantile-onset tonic-clonic and tonic seizures, then spasms in clusters. His electroencephalogram (EEG) showed a burst suppression pattern, leading to the diagnosis of Ohtahara syndrome. Whole-exome sequencing revealed the canonical splice-site variant (c.301 + 1 G > A) in NECAP1. In rodents, Necap1 protein is enriched in neuronal clathrin-coated vesicles and modulates synaptic vesicle recycling. cDNA analysis confirmed abnormal splicing that produced early truncating mRNA. There has been only one previous report of a mutation in NECAP1 in a family with EIEE; this was a nonsense mutation (p.R48*) that was cited as EIEE21. Decreased mRNA levels and the loss of the WXXF motif in both the families suggests that loss of NECAP1 function is a common pathomechanism for EIEE21. This study provided additional support that synaptic vesicle recycling plays a key role in epileptogenesis.
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http://dx.doi.org/10.1038/s10038-018-0556-2DOI Listing
April 2019

SOFT syndrome in a patient from Chile.

Am J Med Genet A 2019 03 20;179(3):338-340. Epub 2018 Dec 20.

Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan.

SOFT syndrome (MIM614813) is an extremely rare primordial dwarfism caused by biallelic mutations in the POC1A gene. It is characterized by prenatal short stature, onychodysplasia, facial dysmorphism, hypotrichosis, and variable skeletal abnormalities including hypoplastic pelvis and sacrum, small hands, and cone-shaped epiphyses, as well as delayed bone age. To the best of our knowledge, only eight POC1A mutations have been reported in humans to date. We report a 7-year-old Chilean girl with SOFT syndrome arising from a novel POC1A mutation c. 649C>T, p.Arg217Trp. Although her clinical features were largely compatible with SOFT syndrome, hand X-ray examinations at 3.5 and 6 years unexpectedly showed normal bone age. Automated bone age determination was performed using image analysis software, BoneXpert. This case highlights the importance of the accumulation of patients with POC1A mutations to further elucidate the detailed clinical features of SOFT syndrome.
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http://dx.doi.org/10.1002/ajmg.a.61015DOI Listing
March 2019