小坂 仁

We report a case of severe Aicardi-Goutières syndrome caused by a novel homozygous RNASEH2B intronic variant, NC_000013.10(NM_024570.4):c.65-13G > A p.Glu22Valfs*5. The patient was born with pseudo-TORCH symptoms, including intracranial calcification, cataracts, and hepatosplenomegaly. Furthermore, the patient exhibited profound intellectual impairment and died at 14 months due to aspiration pneumonia accompanied by interstitial lung abnormalities. The severity of the patient's symptoms underscores the critical role of the C-terminal region of RNase H2B.

It is difficult to differentiate between coronavirus disease 2019 (COVID-19) and influenza based on the symptoms. In the present study, a newly developed antigen rapid diagnostic test (Ag-RDT) called Panbio™ COVID-19/Flu A&B that can simultaneously detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/B virus was evaluated. Its accuracy was evaluated using 235 pairs of nasopharyngeal samples collected from patients with respiratory symptoms and fever (>37.5°C). Reverse transcription polymerase chain reaction was used as a reference method to evaluate the accuracy of the SARS-CoV-2 detection. We confirmed the accuracy of the developed Ag-RDT against the Omicron variant where the sensitivity and specificity were 94.8% and 100%, respectively. In addition, to identify the influenza A virus, a noninferiority test was conducted using a commercial Ag-RDT, which has a sensitivity and specificity in comparison with viral culture of 94.8% and 98.4%, respectively. The positive and negative predictive values for influenza A virus were 98.5% and 98.1%, respectively, for the Panbio COVID-19/Flu A&B test. The evaluation of this newly developed Ag-RDT using clinical samples suggests that it has a high efficacy in clinical settings.

Originally, apomorphine was a broad-spectrum dopamine agonist with an affinity for all subtypes of the Dopamine D1 receptor to the D5 receptor. We previously identified apomorphine as a potential therapeutic agent for mitochondrial diseases by screening a chemical library of fibroblasts from patients with mitochondrial diseases. In this study, we showed that apomorphine prevented ferroptosis in fibroblasts from various types of mitochondrial diseases as well as in normal controls. Well-known biomarkers of ferroptosis include protein markers such as prostaglandin endoperoxide synthase 2 (PTGS2), a key gene for ferroptosis-related inflammation PTGS2, lipid peroxidation, and reactive oxygen species. Our findings that apomorphine induced significant downregulation of PTSG2 and suppressed lipid peroxide to the same extent as other inhibitors of ferroptosis also indicate that apomorphine suppresses ferroptosis. To our knowledge, this is the first study to report that the anti-ferroptosis effect of apomorphine is not related to dopamine receptor agonist action and that apomorphine is a potent inhibitor of ferroptotic cell death independent of dopaminergic receptors.

Thermal airway injuries, usually accompanied by facial burns, require emergency management. We encountered a pediatric case of a late airway-scalding injury without any initial signs of scalding on the face or inside the oral cavity. A 16-month-old boy was accidentally exposed to boiling water from overhead and developed tachypnea and dyspnea at 8 h after the injury. When he visited our hospital at 12 h after the injury, there were no scalding-related findings on his face or inside his oral cavity; however, severe laryngeal edema was observed, which required emergency intubation. Thermal airway injuries can occur later, even if there is no evidence of facial or oral scalding immediately after the injury. Airway injuries should be considered when a patient has been exposed to hot water from overhead.

6歳男児。2歳過ぎより目立っていた尖足に対して、3歳2ヵ月時に当科へ紹介受診となった。所見では両下肢ともに尖足位で、独歩は可能であったが、膝関節を伸展させた状態で歩行していた。対処として両下肢の尖足に対して理学療法や下腿三頭筋へのボトックス注射が行われたが、5歳頃より連続歩行距離が短くなり、長距離の移動には車いすが必要となった。そこで、緩徐に進行する痙性対麻痺症状から遺伝子検査を行った結果、本症例は軽度知的障害を合併したp.Arg239Cysによる遺伝性痙性対麻痺と診断された。6歳7ヵ月時にアキレス腱延長術を行った結果、目下は連続歩行距離は500mで、疲労時や移動の際は車いすを使用している。

小児採血の特徴として,血管径が細いこと,検査への協力が得られにくいこと,採取量確保の困難さがあり,低侵襲かつ微量測定が可能な採血法の確立が望まれている。今回,小児における,多機能微量採血管キャピラリーカップで採取した指頭血検体と,注射針を用いて採取した静脈血検体との検査値の相関性を検討した。対象項目は,TP,Alb,AST,ALT,LD,BUN,Cr,BS,CRPの生化学検査9項目と,WBC,RBC,Hb,Ht,Pltの血球計数検査5項目とした。両検査値の相関関係からTP,Alb,AST,ALT,BUN,Cr,CRP,WBCに相関性を認め,これらの項目においては,指頭採血は静脈採血に代替しうる可能性がある。指頭採血により,小児採血が簡便化し,低侵襲な血液検査が普及することで,被験者の負担軽減はもちろん,検査者の負担軽減にもつながると考えられる。(著者抄録)

Menkes disease is an X-linked disorder of copper metabolism caused by mutations in the ATP7A gene, and female carriers are usually asymptomatic. We describe a 7-month-old female patient with severe intellectual disability, epilepsy, and low levels of serum copper and ceruloplasmin. While heterozygous deletion of exons 16 and 17 of the ATP7A gene was detected in the proband, her mother, and her grandmother, only the proband suffered from Menkes disease clinically. Intriguingly, X chromosome inactivation (XCI) analysis demonstrated that the grandmother and the mother showed skewing of XCI toward the allele with the ATP7A deletion and that the proband had extremely skewed XCI toward the normal allele, resulting in exclusive expression of the pathogenic ATP7A mRNA transcripts. Expression bias analysis and recombination mapping of the X chromosome by the combination of whole genome and RNA sequencing demonstrated that meiotic recombination occurred at Xp21-p22 and Xq26-q28. Assuming that a genetic factor on the X chromosome enhanced or suppressed XCI of its allele, the factor must be on either of the two distal regions derived from her grandfather. Although we were unable to fully uncover the molecular mechanism, we concluded that unfavorable switching of skewed XCI caused Menkes disease in the proband.

BACKGROUND: Behavioral problems of foster children are an important issue for the maintenance of the foster care system, but they have not been adequately studied in Japan. We used the Eyberg Child Behavior Inventory (ECBI) to investigate behavioral problems among foster children and to examine associated factors. METHODS: Twenty-nine foster children and their foster parents and 479 non-foster children and parents were recruited for the foster and control groups, respectively. Both groups underwent statistical comparative analyses using data from their ECBI assessments. The ECBI has two scales: the Intensity Scale quantifies the severity of child behavioral problems, and the Problem Scale captures the caregiver's perceived difficulties handling each behavior. We conducted a retrospective investigation of the background of the foster parent-child pairs to explore potential causal relationships with behavioral problems. RESULTS: The mean intensity score for the foster group was significantly higher than that for the control group (p = 0.001). The mean problem scores for the foster group and the control group were not significantly different (p = 0.79). In the foster group, the retrospective investigation revealed two children with neurological or neurodevelopmental disorders, 17 with histories of abuse, and 10 with other issues. CONCLUSION: Intensity scores showed severe behavioral problems among foster children, perhaps caused by neurological disorders, abuse, parental mental health, or economic hardship. Problem scores showed no significant differences between groups. It can therefore be posited that foster parents might exhibit a more lenient parenting style when dealing with children who have a history of abuse by their biological parents.

BACKGROUND: Premature children are known to be at a high risk of developing behavioral problems. This study examined the effectiveness of parent-child interaction therapy (PCIT) in reducing behavioral problems in young children born premature. METHODS: The study included 18 child-parent pairs with children born at less than 35 weeks of gestation (range: 23-34 weeks, median: 31.0 weeks) and aged 27-52 months (median: 38.0 months). They were assigned to either the PCIT group (n = 7) or the non-PCIT group (n = 11) based on maternal desire for treatment. The study was designed to examine the effects of PCIT. Specifically, the Eyberg Child Behavior Inventory (ECBI) intensity score, ECBI problem score, and Parenting Stress Index Short Form (PSI-SF) scores were compared before treatment and after 6 months. RESULTS: In the PCIT group, the mean ECBI intensity score was 135.7 (SD = 13.5; T-score = 64) at baseline and 90.1 (SD = 15.5; T-score = 46) at post-assessment, the mean ECBI problem score was 9.8 (SD = 1.9; T-score = 54) at baseline and 4.4 (SD = 3.1; T-score = 44) at post-assessment, the mean PSI-SF total score was 60.1 (SD = 4.8; 95%tile) at baseline and 49.6 (SD = 5.6; 85%tile) at post-assessment, showing a significant improvement (ECBI intensity scores: p < 0.001, d = 2.03; ECBI problem scores: p < 0.001, d = 1.94; PSI-SF total scores: p = 0.004, d = 0.86). On the other hand, none of the scores showed significant change in the non-PCIT group. CONCLUSIONS: The PCIT can be considered as a potential treatment option for behavioral problems in young children born premature.

急性副鼻腔炎は小児に多い疾患であるが,保存的治療が奏効する症例が多く,外科的治療を要する症例は稀である。重篤な合併症は眼窩骨膜下膿瘍や硬膜外膿瘍であり,進行例では約30%に視力障害が残る。我々は,急性副鼻腔炎を契機とした眼窩骨膜下膿瘍の2症例を経験した。早期に抗菌薬治療を開始したが,眼球運動障害や視力障害を併発したため,速やかに外科的ドレナージ術を行い,重篤な視覚後遺症はなく回復した。また,magnetic resonance imaging検体を用いたことにより,眼窩構造物および膿瘍の正確な評価をすることができた。(著者抄録)

Mendelson症候群は胃酸の誤嚥による化学性肺炎であり,誤嚥時および誤嚥後数時間以降の二相性の呼吸障害が特徴的である。意識障害,喉頭反射低下,フルストマックなどの状況がリスク因子である。熱性けいれん時の誤嚥により発症した重症のMendelson症候群を報告する。症例は1歳男児。昼食後に強直間代性けいれんが出現した。止痙後に嘔吐し,嘔吐後から低酸素血症を認め気管挿管された。第2病日に急激な肺高血圧から心停止に至り静脈脱血・動脈送血体外式膜型人工肺(venoarterial extracorporeal membrane oxygenation,以下VA ECMO)を導入した。その後,一酸化窒素吸入療法を含めた集学的治療を行い心機能および肺高血圧の所見は徐々に改善し第9病日にECMOを離脱,第38病日に明らかな神経学的後遺症はなく退院した。食後に発症したけいれんでは胃酸誤嚥のリスクが高く,経時的な呼吸循環動態の評価が重要である。(著者抄録)

BACKGROUND: Niemann-Pick disease type C (NPC) is an autosomal recessive inherited and neurodegenerative disorder. Approximately 10% of NPC patients have acute liver failure and sometimes need liver transplantation (LT), and 7% reportedly develop inflammatory bowel disease (IBD). We report the case of a girl with NPC who had a re- accumulation of cholesterol in the transplanted liver and NPC-related IBD. CASE REPORT: The patient underwent living donor liver transplantation (LDLT) due to severe acute liver failure caused by an unknown etiology inherited from her father. At 1 year and 6 months (1Y6M), she developed neurological delay, catalepsy, and vertical supranuclear gaze palsy. The foam cells were found in her skin, and fibroblast Filipin staining was positive; hence, she was diagnosed with NPC. It was identified that her father had NPC heterozygous pathogenic variant. At 2 years, she had anal fissure, skin tag and diarrhea. She was diagnosed with NPC-related IBD, using a gastrointestinal endoscopy. Three years after LT, liver biopsy revealed foam cells and numerous fatty droplets. At 8 years, broken hepatocytes and substantial fibrosis were observed. She died from circulation failure due to hypoalbuminemia at 8Y2M. CONCLUSIONS: In NPC, load of cholesterol metabolism is suggested to persist even after LT. LDLT from NPC heterozygous variant donor was insufficient to metabolize cholesterol overload. In NPC patients, the possibility of cholesterol re-accumulation should be considered when LT is performed. NPC-related IBD should be considered when NPC patients have anorectal lesions or diarrhea.

Corona virus infectious disease, emerged in 2019(COVID-19)は、流行の主体が感染性の高いオミクロン変異株に置き換わり小児の感染者数が増加し、けいれん、意識障害、脳炎・脳症例も増加し、重症化する症例や後遺症を残す症例も報告されている。われわれが経験した小児COVID-19の出血性ショック脳症症候群や、片側けいれん・片麻痺・てんかん症候群を含む3症例の急性脳症を提示する。小児COVID-19の急性脳症はインフルエンザ脳症と同様、さまざまな臨床病型・重症度、そして予後をとりうる。(著者抄録)

Corona virus infectious disease, emerged in 2019(COVID-19)は、流行の主体が感染性の高いオミクロン変異株に置き換わり小児の感染者数が増加し、けいれん、意識障害、脳炎・脳症例も増加し、重症化する症例や後遺症を残す症例も報告されている。われわれが経験した小児COVID-19の出血性ショック脳症症候群や、片側けいれん・片麻痺・てんかん症候群を含む3症例の急性脳症を提示する。小児COVID-19の急性脳症はインフルエンザ脳症と同様、さまざまな臨床病型・重症度、そして予後をとりうる。(著者抄録)

We discovered biallelic intragenic structural variations (SVs) inFGF12by applying long-read whole genome sequencing to an exome-negative patient with developmental and epileptic encephalopathy (DEE). We also found another DEE patient carrying a biallelic (homozygous) single-nucleotide variant (SNV) inFGF12that was detected by exome sequencing.FGF12heterozygous recurrent missense variants with gain-of-function or heterozygous entire duplication ofFGF12are known causes of epilepsy, but biallelic SNVs/SVs have never been described.FGF12encodes intracellular proteins interacting with the C-terminal domain of the alpha subunit of voltage-gated sodium channels 1.2, 1.5, and 1.6, promoting excitability by delaying fast inactivation of the channels. To validate the molecular pathomechanisms of these biallelicFGF12SVs/SNV, highly sensitive gene expression analyses using lymphoblastoid cells from the patient with biallelic SVs, structural considerations, andDrosophilain vivo functional analysis of the SNV were performed, confirming loss-of-function. Our study highlights the importance of small SVs in Mendelian disorders, which may be overlooked by exome sequencing but can be detected efficiently by long-read whole genome sequencing, providing new insights into the pathomechanisms of human diseases.

BACKGROUND: Enoyl-CoA hydratase short-chain 1 (ECHS1) is an enzyme involved in the metabolism of branched chain amino acids and fatty acids. Mutations in the ECHS1 gene lead to mitochondrial short-chain enoyl-CoA hydratase 1 deficiency, resulting in the accumulation of intermediates of valine. This is one of the most common causative genes in mitochondrial diseases. While genetic analysis studies have diagnosed numerous cases with ECHS1 variants, the increasing number of variants of uncertain significance (VUS) in genetic diagnosis is a major problem. METHODS: Here, we constructed an assay system to verify VUS function for ECHS1 gene. A high-throughput assay using ECHS1 knockout cells was performed to index these phenotypes by expressing cDNAs containing VUS. In parallel with the VUS validation system, a genetic analysis of samples from patients with mitochondrial disease was performed. The effect on gene expression in cases was verified by RNA-seq and proteome analysis. RESULTS: The functional validation of VUS identified novel variants causing loss of ECHS1 function. The VUS validation system also revealed the effect of the VUS in the compound heterozygous state and provided a new methodology for variant interpretation. Moreover, we performed multiomics analysis and identified a synonymous substitution p.P163= that results in splicing abnormality. The multiomics analysis complemented the diagnosis of some cases that could not be diagnosed by the VUS validation system. CONCLUSIONS: In summary, this study uncovered new ECHS1 cases based on VUS validation and omics analysis; these analyses are applicable to the functional evaluation of other genes associated with mitochondrial disease.

Autism spectrum disorder (ASD) is caused by combined genetic and environmental factors. Genetic heritability in ASD is estimated as 60-90%, and genetic investigations have revealed many monogenic factors. We analyzed 405 patients with ASD using family-based exome sequencing to detect disease-causing single-nucleotide variants (SNVs), small insertions and deletions (indels), and copy number variations (CNVs) for molecular diagnoses. All candidate variants were validated by Sanger sequencing or quantitative polymerase chain reaction and were evaluated using the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines for molecular diagnosis. We identified 55 disease-causing SNVs/indels in 53 affected individuals and 13 disease-causing CNVs in 13 affected individuals, achieving a molecular diagnosis in 66 of 405 affected individuals (16.3%). Among the 55 disease-causing SNVs/indels, 51 occurred de novo, 2 were compound heterozygous (in one patient), and 2 were X-linked hemizygous variants inherited from unaffected mothers. The molecular diagnosis rate in females was significantly higher than that in males. We analyzed affected sibling cases of 24 quads and 2 quintets, but only one pair of siblings shared an identical pathogenic variant. Notably, there was a higher molecular diagnostic rate in simplex cases than in multiplex families. Our simulation indicated that the diagnostic yield is increasing by 0.63% (range 0-2.5%) per year. Based on our simple simulation, diagnostic yield is improving over time. Thus, periodical reevaluation of ES data should be strongly encouraged in undiagnosed ASD patients.

Coenzyme Q10 (CoQ10) is involved in ATP production through electron transfer in the mitochondrial respiratory chain complex. CoQ10 receives electrons from respiratory chain complex I and II to become the reduced form, and then transfers electrons at complex III to become the oxidized form. The redox state of CoQ10 has been reported to be a marker of the mitochondrial metabolic state, but to our knowledge, no reports have focused on the individual quantification of reduced and oxidized CoQ10 or the ratio of reduced to total CoQ10 (reduced/total CoQ10) in patients with mitochondrial diseases. We measured reduced and oxidized CoQ10 in skin fibroblasts from 24 mitochondrial disease patients, including 5 primary CoQ10 deficiency patients and 10 respiratory chain complex deficiency patients, and determined the reduced/total CoQ10 ratio. In primary CoQ10 deficiency patients, total CoQ10 levels were significantly decreased, however, the reduced/total CoQ10 ratio was not changed. On the other hand, in mitochondrial disease patients other than primary CoQ10 deficiency patients, total CoQ10 levels did not decrease. However, the reduced/total CoQ10 ratio in patients with respiratory chain complex IV and V deficiency was higher in comparison to those with respiratory chain complex I deficiency. Measurement of CoQ10 in fibroblasts proved useful for the diagnosis of primary CoQ10 deficiency. In addition, the reduced/total CoQ10 ratio may reflect the metabolic status of mitochondrial disease.

BACKGROUND: Eight waves of the coronavirus disease 2019 (COVID-19) epidemic have been observed in Japan. This retrospective study was conducted to clarify the clinical characteristics of pediatric COVID-19 patients. METHODS: We studied 121 patients admitted to the Jichi Children's Medical Center Tochigi between April 2020 and March 2023. Incidence of pediatric COVID-19 in Tochigi Prefecture was used to examine hospitalization and severe illness rates. RESULTS: The mean age of the patients was 3 years and 8 months. One hundred and eleven patients (91.7%) were hospitalized after January 2022 (after the 6th wave), when the Omicron strain became endemic in Japan. Convulsions occurred in 30 patients (24.8%), all of whom were admitted after the 6th wave. Twenty-three of the 30 patients had no underlying disease. Eleven patients (9.1%) were diagnosed with acute encephalopathy. One patient died due to hemorrhagic shock and encephalopathy syndrome and two had sequelae after the 6th wave. The patient who died due to encephalopathy had hypercytokinemia. In the Tochigi Prefecture, the number of pediatric COVID-19 patients increased after the 6th wave, but the hospitalization rate declined. The rate of severe illness did not change before the end of 5th and after the 6th wave. CONCLUSION: Although the rate of severe illness in patients with pediatric COVID-19 did not increase after the 6th wave, some patients had complicated critical illnesses. Systemic inflammatory reaction was considered to have been associated with the severe encephalopathy.

Abstract Static encephalopathy of childhood with neurodegeneration in adulthood/β-propeller protein-associated neurodegeneration is a neurodegenerative disorder with brain iron accumulation caused by the variants of WDR45, a core autophagy-related gene that encodes WIPI4. However, the pathophysiology of the disease, particularly the function of WDR45/WIPI4 in iron metabolism, is largely unknown. As no other variants of core autophagy-related genes show abnormalities in iron metabolism, the relation between autophagy and iron metabolism remains to be elucidated. Since iron deposition in the brain is the hallmark of static encephalopathy of childhood with neurodegeneration in adulthood/β-propeller protein-associated neurodegeneration, iron chelation therapy has been attempted, but it was found to worsen the symptoms; thus, the establishment of a curative treatment is essential. Here, we evaluated autophagy and iron metabolism in patient-derived cells. The expression of ferritin and ferric iron increased and that of ferrous iron decreased in the patient cells with WDR45 variants. In addition, the expression of nuclear receptor coactivator 4 was markedly reduced in patient-derived cells. Furthermore, divalent metal transporter 1, which takes in ferrous iron, was upregulated, while ferroportin, which exports ferrous iron, was downregulated in patient-derived cells. The transfer of WDR45 via an adeno-associated virus vector restored WIPI4 and nuclear receptor coactivator 4 expression, reduced ferritin levels, and improved other phenotypes observed in patient-derived cells. As nuclear receptor coactivator 4 mediates the ferritin-specific autophagy, i.e., ferritinophagy, its deficiency impaired ferritinophagy, leading to the accumulation of ferric iron‒containing ferritin and insufficiency of ferrous iron. Because ferrous iron is required for various essential biochemical reactions, the changes in divalent metal transporter 1 and ferroportin levels may indicate a compensatory response for maintaining the intracellular levels of ferrous iron. Our study revealed that the pathophysiology of static encephalopathy of childhood with neurodegeneration in adulthood/β-propeller protein-associated neurodegeneration involves ferrous iron insufficiency via impaired ferritinophagy through nuclear receptor coactivator 4 expression reduction. Our findings could aid in developing a treatment strategy involving WDR45 manipulation, which may have clinical applications.

We report on a patient with a distal 16.4-Mb duplication at 2q36.3-qter, who presented with severe intellectual disability, microcephaly, brachycephaly, prominent forehead, hypertelorism, prominent eyes, thin upper lip, and progenia. Copy number analysis using whole exome data detected a distal 2q duplication. This is the first report describing a distal 2q duplication at the molecular level.

Embryonic development is dictated by tight regulation of DNA replication, cell division and differentiation. Mutations in DNA repair and replication genes disrupt this equilibrium, giving rise to neurodevelopmental disease characterized by microcephaly, short stature and chromosomal breakage. Here, we identify biallelic variants in two components of the RAD18-SLF1/2-SMC5/6 genome stability pathway, SLF2 and SMC5, in 11 patients with microcephaly, short stature, cardiac abnormalities and anemia. Patient-derived cells exhibit a unique chromosomal instability phenotype consisting of segmented and dicentric chromosomes with mosaic variegated hyperploidy. To signify the importance of these segmented chromosomes, we have named this disorder Atelís (meaning - incomplete) Syndrome. Analysis of Atelís Syndrome cells reveals elevated levels of replication stress, partly due to a reduced ability to replicate through G-quadruplex DNA structures, and also loss of sister chromatid cohesion. Together, these data strengthen the functional link between SLF2 and the SMC5/6 complex, highlighting a distinct role for this pathway in maintaining genome stability.