Exome sequencing reveals a novel TTC19 mutation in an autosomal recessive spinocerebellar ataxia patient

BACKGROUND: Spinocerebellar ataxias (SCAs) are heterogeneous diseases characterized by progressive cerebellar ataxia associated with dysarthria, oculomotor abnormalities, and mental impairment. To identify the causative gene, we performed exome sequencing on a Japanese patient clinically diagnosed with recessive SCA. METHOD: The patient is a 37-year-old Japanese woman with consanguineous parents. The head magnetic resonance imaging (MRI) showed cerebellar atrophy and T1 low/T2 high intensity at the bilateral inferior olives. Single-nucleotide polymorphism (SNP) genotyping and next-generation sequencing were performed, and the variants obtained were filtered and prioritized. RESULTS: After these manipulations, we identified a homozygous nonsense mutation of the TTC19 gene (p.Q277*). TTC19 has been reported to be a causative gene of a neurodegenerative disease in Italian and Portuguese families and to be involved in the pathogenesis of mitochondrial respiratory chain complex III (cIII) deficiency. This report is the first description of a TTC19 mutation in an Asian population. Clinical symptoms and neuroimaging are consistent with previous reports. The head MRI already showed abnormal features four years before her blood lactate and pyruvate levels were elevated. CONCLUSIONS: We should consider the genetic analysis of TTC19 when we observe such characteristic MRI abnormalities. Genes associated with mitochondrial function cause many types of SCAs; the mutation we identified should help to elucidate the pathology of these disorders

Analysis on the Susceptibility Genes in Two Chinese Pedigrees with Familial Parkinson's Disease

Objective. To screen the susceptibility genes in Chinese pedigrees with early-onset familial Parkinson's disease (FPD). Methods. Fifty-one genomic DNA samples extracted from two Chinese pedigrees with FPD, the alpha-synuclein genes (SNCA), the leucine-rich repeat kinase 2(LRRK2), PINK1(PTEN-induced putative kinase 1), PARK7(Protein DJ1), PARK2(Parkinson juvenile disease protein 2), the glucocerebrosidase (GBA), and ATP(Ezrin-binding protein PACE-1), were sequenced by the use of polymerase chain reaction (PCR) technique. The gene dose of SNCA was checked. Results. There were only two missense mutations observed, respectively, at exon 5 of LRRK2 and exon 10 of PARK2, and both were enrolled in SNPs. Conclusion. No meaningful mutations could be detected, and other susceptibility genes should be detected in FDP patients in China

High Excess Risk of Heart Disease Mortality among Hiroshima Atomic Bomb Male Survivors Exposed Near the Hypocenter

Heart disease (HD) mortality is the second leading cause of death in Japan. The HD mortality risk among Atomic bomb survivors is slightly positive but shows a statistically significant dose-response relationship with initial radiation dose, as reported by the Radiation Effects Research Foundation. In that report, dosimetry was based on initial radiation only, with the effect of indirect radiation dose not taken into consideration. The atomic bomb radiation, however, consisted of both initial and residual radiation. We reevaluated the dose-response relationship for HD mortality using exposure distance (ground distance between the location where exposed and the hypocenter) as a surrogate indicator of radiation dose. At Hiroshima University, a cohort study has been conducted with Hiroshima Atomic Bomb Survivors (ABS) since 1970. We selected 29605 subjects from the ABS who were exposed at 3.5 km or less from the hypocenter and alive on January 1, 1970. These subjects, referred to as “Hiroshima hibakusha” in this paper, were followed until December 31, 2010. We stratified the cohort data with respect to sex and age at the time of bombing (ATB) into 10-year age groups. For each stratum, by applying an extended Cox regression model with time-dependent covariates, we analyzed the risk of HD mortality using either initial radiation dose or exposure distance as an explanatory variable. The results indicate a high excess risk in males and older age ATB females who were exposed near the hypocenter. This difference may be explained by the effect of female sex hormone on the circulatory system among young age ATB females. Some unknown risk factor related to exposure distance was also implicated in the elevated risk of HD among the Hiroshima hibakusha, especially in males. This necessitates further study.This research was supported in part by Grants-in-Aid for Scientific Research (A) 24249039 (2012–2014), and the Joint Usage/Research Center (RIRBM), Hiroshima University

Screening for OPTN mutations in amyotrophic lateral sclerosis in a mainly Caucasian population

Mutations in the optineurin (OPTN) gene cause amyotrophic lateral sclerosis (ALS). We previously reported 3 types of OPTN mutation in Japanese ALS subjects. Here, to identify the OPTN mutations in individuals of different ethnicity, we screened 563 sporadic ALS (SALS) subjects and 124 familial ALS (FALS) subjects who were mainly Caucasian. We found a c. 964T>C synonymous variation in exon 8. However, we could not find the meaningful OPTN mutations. The results indicate that OPTN mutations causing ALS are rare, especially in mainly Caucasian ALS subjects

High Initial-dose Dependency of Cerebrovascular Disease Mortality among Female Survivors of the Hiroshima Atomic Bomb Exposed in Teens : A Cohort Study, 1970-2010

Several studies have been conducted on cerebrovascular disease mortality in Atomic bomb survivors. Previous studies have investigated the relationship between mortality and initial radiation dose after adjusting for the effects of sex and age at the time of the bombing (ATB), and detected a weak (but statistically significant) dose-response relationship was detected. The objective of the present study was to examine whether the sex- and age ATB-specific cerebrovascular disease mortality among Hiroshima atomic bomb survivors can be explained by the initial radiation dose. At Hiroshima University, a cohort study has been conducted with Hiroshima Atomic Bomb Survivors (ABS) since 1970. We selected 30,378 subjects from the ABS who were exposed at 3.5 km or less from the hypocenter and still alive on January 1, 1970. These subjects were followed up until December 31, 2010. The cohort data were stratified with respect to sex and age ATB into 10-year age groups. For each stratum, using Cox regression, we performed survival analyses of the risk of cerebrovascular mortality using the initial radiation dose and the exposure distance (the ground distance between the exposure location and the hypocenter) as explanatory variables. The results indicated that the risks to females exposed at 10 to 19 years old were highly dependent on the initial radiation dose (hazard ratio: 1.51, p < 0.001), while the risks to males were not. There might exist some radiation exposure effects limited to women who were in their teens at the time of exposure. However, the background mechanisms remain unclear, necessitating further study.This study was supported in part by Grants-in-Aid for Scientific Research (A) 24249039, Young Scientists (B) 23790694, and 23700337 from the Japanese Ministry of Education, Culture, Sports, Science and Technology

Optineurin with amyotrophic lateral sclerosis-related mutations abrogates inhibition of interferon regulatory factor-3 activation

Optineurin has been shown to be involved in primary open-angle glaucoma. We recently found that optineurin is involved in familial amyotrophic lateral sclerosis (ALS). On the other hand, optineurin has been shown to inhibit transcription factors related to innate immunity such as NF-kappa B and interferon regulatory factor-3 (IRF3). In the present study, the effect of ALS-associated optineurin mutations on IRF3 activation was investigated. Optineurin inhibited IRF3 activation induced by melanoma differentiation-associated gene 5 or Toll-IL-1 receptor domain-containing adaptor-inducing interferon-beta. The inhibition was abrogated by mutations related to ALS but not by a mutation related to glaucoma. Reporter assay indicated that the JAK-STAT signaling pathway was not affected by optineurin. These results show that ALS-related optineurin is involved in the IRF3 activation pathway. Pathogenesis of ALS may be associated with some kind of innate immunity, especially that against virus infection, through IRF3 activation

<ORIGINAL ARTICLE>The effects of sagittal ramus osteotomy for mandibular prognathism on maximum mouth opening and condylar movement

Maximum mouth opening and condylar movement before and more than 6 months after surgery were analyzed in 23 cases of sagittal ramus osteotomy of the mandible for correction of mandibular prognathism. Condylar movement (translation and rotation) did not show postoperatively a significant difference pre-and postoperatively, and then was a tendency to a reduction of maximum mouth opening was found

ALS clinically presenting with PMA

Amyotrophic lateral sclerosis (ALS) primarily affects upper and lower motor neurons. Phosphorylated TAR DNA-binding protein of 43 kDa (TDP-43) inclusion bodies are reportedly a pathological hallmark of sporadic ALS. Here, we present an atypical case of sporadic ALS that progressed very slowly, persisted for 19 years, and clinically appeared to only affect the lower motor neurons; however, upper motor neuron degeneration was detected on autopsy. Furthermore, no inclusion bodies positive for phosphorylated TDP-43, ubiquitin, fused in sarcoma, or SOD1 were detected in the CNS. We performed exome-sequencing data analysis but found no genetic disorders. This was therefore an unusual case of lower motor neuron-predominant ALS without TDP-43 pathology or known gene-disease associations. We also reviewed autopsied ALS cases that progressed slowly and had no phosphorylated TDP-43 or ubiquitin positive inclusions and present the clinicopathological features of such cases. Based on these results, there may be a sporadic ALS subgroup that progresses slowly and shows 76 no accumulation of phosphorylated TDP-43

Genetic screening for malignant hyperthermia and comparison of clinical symptoms in Japan

Malignant hyperthermia (MH) is an anaesthetic complication that causes an abnormal hypermetabolic state. RYR1 encoding ryanodine receptors of the sarcoplasmic reticulum and CACNA1S encoding α subunits of dihydropyridine receptors are known to be associated with MH pathogenicity. We performed genetic screening using next-generation sequencing to evaluate the prevalence of genes associated with MH pathogenicity and clinical symptoms. This was a retrospective cohort study wherein next-generation sequencing data of 77 families diagnosed with MH predisposition by calcium-induced calcium release (CICR) tests from 1995 to 2019 was used to search for RYR1 and CACNA1S variants. Furthermore, the clinical symptoms and predisposition tests in participants with RYR1 and CACNA1S variants were compared. In the 77 families, 44.2%, 7.8%, and 48.1% individuals had RYR1, CACNA1S, and neither RYR1 nor CACNA1S variants, respectively. Clinically significant differences were found in the maximum body temperature, maximum elevated body temperature for 15 min, creatinine kinase level, and CICR rate between the RYR1 and CACNA1S groups. The prevalence of pathogenic CACNA1S variants appears to be prominent in Japan. The severity of clinical symptoms and the CICR rate were greater in individuals with RYR1 variants than in those with CACNA1S variants, likely due to more direct regulation of calcium levels by ryanodine receptors than by dihydropyridine receptors. Genetic analysis of MH in future studies may help identify other genes associated with MH, which will further clarify the relationship between genotypes and MH symptoms and contribute to safer anaesthesia practice.This study was supported by a Grant-in-Aid for Young Scientists (grant number: 17K16733 to Y.N. and 20K17783 to R.K.) from the Japan Society for the Promotion of Science and by the Takeda Science Foundation (H.K.)

Prediction Model of Amyotrophic Lateral Sclerosis by Deep Learning with Patient Induced Pluripotent Stem Cells

Deep LearningとALS iPS細胞を用いた疾患予測テクノロジー --人工知能のALS検知・診断への応用--. 京都大学プレスリリース. 2021-02-24.Deep learning amyotrophic lateral sclerosis by taking pictures. 京都大学プレスリリース. 2021-02-24.In amyotrophic lateral sclerosis (ALS), early diagnosis is essential for both current and potential treatments. To find a supportive approach for the diagnosis, we constructed an artificial intelligence‐based prediction model of ALS using induced pluripotent stem cells (iPSCs). Images of spinal motor neurons derived from healthy control subject and ALS patient iPSCs were analyzed by a convolutional neural network, and the algorithm achieved an area under the curve of 0.97 for classifying healthy control and ALS. This prediction model by deep learning algorithm with iPSC technology could support the diagnosis and may provide proactive treatment of ALS through future prospective research. ANN NEUROL 202