Comprehensive collection of genes and comparative analysis of full-length transcriptome sequences from Japanese larch (Larix kaempferi) and Kuril larch (Larix gmelinii var. japonica).

BACKGROUND: Japanese larch (Larix kaempferi) is an economically important deciduous conifer species that grows in cool-temperate forests and is endemic to Japan. Kuril larch (L. gmelinii var. japonica) is a variety of Dahurian larch that is naturally distributed in the Kuril Islands and Sakhalin. The hybrid larch (L. gmelinii var. japonica × L. kaempferi) exhibits heterosis, which manifests as rapid juvenile growth and high resistance to vole grazing. Since these superior characteristics have been valued by forestry managers, the hybrid larch is one of the most important plantation species in Hokkaido. To accelerate molecular breeding in these species, we collected and compared full-length cDNA isoforms (Iso-Seq) and RNA-Seq short-read, and merged them to construct candidate gene as reference for both Larix species. To validate the results, candidate protein-coding genes (ORFs) related to some flowering signal-related genes ​were screened from the reference sequences, and the phylogenetic relationship with closely related species was elucidated. RESULTS: Using the isoform sequencing of PacBio RS ll and the de novo assembly of RNA-Seq short-read sequences, we identified 50,690 and 38,684 ORFs in Japanese larch and Kuril larch, respectively. BUSCO completeness values were 90.5% and 92.1% in the Japanese and Kuril larches, respectively. After comparing the collected ORFs from the two larch species, a total of 19,813 clusters, comprising 22,571 Japanese larch ORFs and 22,667 Kuril larch ORFs, were contained in the intersection of the Venn diagram. In addition, we screened several ORFs related to flowering signals (SUPPRESSER OF OVEREXPRESSION OF CO1: SOC1, LEAFY: LFY, FLOWERING Locus T: FT, CONSTANCE: CO) from both reference sequences, and very similar found in other species. CONCLUSIONS: The collected ORFs will be useful as reference sequences for molecular breeding of Japanese and Kuril larches, and also for clarifying the evolution of the conifer genome and investigating functional genomics.

Early drug development in solid tumours: analysis of National Cancer Institute-sponsored phase 1 trials.

BACKGROUND: The low expectation of clinical benefit from phase 1 cancer therapeutics trials might negatively affect patient and physician participation, study reimbursement, and slow the progress of oncology research. Advances in cancer drug development, meanwhile, might have favourably improved treatment responses; however, little comprehensive data exist describing the response and toxicity associated with phase 1 trials across solid tumours. The aim of the study is to evaluate the trend of toxicity and response in phase 1 trials for solid tumours over time. METHODS: We analysed patient-level data from the Cancer Therapy Evaluation Program of the National Cancer Institute-sponsored investigator-initiated phase 1 trials for solid tumours, from Jan 1, 2000, to May 31, 2019. We assessed risks of treatment-related death (grade 5 toxicity ratings possibly, probably, or definitely attributable to treatment), all on-treatment deaths (deaths during protocol treatment regardless of attribution), grade 3-4 toxicity, and proportion of overall response (complete response and partial response) and complete response rate in the study periods of 2000-05, 2006-12, and 2013-2019, and evaluated their trends over time. We also analysed cancer type-specific and investigational agent-specific response, and analysed the trend of response in each cancer type over time. Univariate associations of overall response rates with patients' baseline characteristics (age, sex, performance status, BMI, albumin concentration, and haemoglobin concentration), enrolment period, investigational agents, and trial design were assessed using risk ratio based on the modified Poisson regression model. FINDINGS: We analysed 465 protocols that enrolled 13 847 patients using 261 agents. 144 (31%) trials used a monotherapy and 321 (69%) used combination therapies. The overall treatment-related death rate was 0·7% (95% CI 0·5-0·8) across all periods. Risks of treatment-related deaths did not change over time (p=0·52). All on-treatment death risk during the study period was 8·0% (95% CI 7·6-8·5). The most common grade 3-4 adverse events were haematological; grade 3-4 neutropenia occurred in 2336 (16·9%) of 13 847 patients, lymphopenia in 1230 (8·9%), anaemia in 894 (6·5%), and thrombocytopenia in 979 (7·1%). The overall response rate for all trials during the study period was 12·2% (95% CI 11·5-12·8; 1133 of 9325 patients) and complete response rate was 2·7% (2·4-3·0; 249 of 9325). Overall response increased from 9·6% (95% CI 8·7-10·6) in 2000-05 to 18·0% (15·7-20·5) in 2013-19, and complete response rates from 2·5% (2·0-3·0) to 4·3% (3·2-5·7). Overall response rates for combination therapy were substantially higher than for monotherapy (15·8% [15·0-16·8] vs 3·5% [2·8-4·2]). The overall response by class of agents differed across diseases. Anti-angiogenesis agents were associated with higher overall response rate for bladder, colon, kidney and ovarian cancer. DNA repair inhibitors were associated with higher overall response rate in ovarian and pancreatic cancer. The rates of overall response over time differed markedly by disease; there were notable improvements in bladder, breast, and kidney cancer and melanoma, but no change in the low response of pancreatic and colon cancer. INTERPRETATION: During the past 20 years, the response rate in phase 1 trials nearly doubled without an increase in the treatment-related death rate. However, there is significant heterogeneity in overall response by various factors such as cancer type, investigational agent, and trial design. Therefore, informed decision making is crucial for patients before participating in phase 1 trials. This study provides updated encouraging outcomes of modern phase 1 trials in solid tumours. FUNDING: National Cancer Institute.

Trends in Grade 5 Toxicity and Response in Phase I Trials in Hematologic Malignancy: 20-Year Experience From the Cancer Therapy Evaluation Program at the National Cancer Institute.

PURPOSE: Cancer drug development has largely shifted from cytotoxic chemotherapy to targeted treatment in the past two decades. Although previous studies have highlighted improvement in response rates in recent phase I trials, disease-focused reporting is limited. METHODS: We integrated patient-level data for patients with hematologic malignancies who participated in phase I trials sponsored by the National Cancer Institute Cancer Therapy Evaluation Program between January 2000 and May 2019 and estimated the trend of grade 5 toxicity and response by disease subtype over time. RESULTS: We analyzed 161 trials involving 3,308 patients, all of whom were assessed for toxicity and 2,404 of whom were evaluable for response to therapy. The overall rate of grade 5 toxicities was 1.81% (95% CI, 1.36 to 2.27), with no significant change in the rate over time. Baseline characteristics associated with higher risk of grade 5 toxicity were age and performance status ≥ 2 at enrollment. Overall response rate (ORR) and complete response (CR) rate for all trials during the study period were 25.1% and 14.7%, respectively. A significant increase in both ORR and CR rate was observed over time (ORR, 18.5% in 2000-2005, 25.9% in 2006-2012, and 50.6% in 2013-2019, P < .001). ORR in phase I trials varied across disease subtypes: 20.2% in acute myeloid leukemia, 9.1% in myelodysplastic syndrome, 43.2% in lymphoma, 42.9% in chronic lymphocytic leukemia, 15.1% in acute lymphoblastic leukemia, and 16.5% in myeloma. CONCLUSION: Over time, the ORR and CR rates in phase I trials for hematologic malignancy have improved meaningfully, whereas the rate of toxicity-related death remains stable. This study provides broad experience that physicians can use when discussing the potential outcomes for patients with hematologic malignancy considering participation in phase I trials.

Analysis of risk factors for multidrug-resistant pathogens and appropriate treatment indications for pneumonia in children with neurologic impairment.

INTRODUCTION: The features of pneumonia in children with neurologic impairment (NI) resemble those of healthcare-associated pneumonia is defined as pneumonia occurring in the community associated with healthcare risk factors. There are currently no guidelines for the treatment of pneumonia in children with NI. Here, we assessed whether the guidelines applicable for treating pneumonia in adults could be applied to children with NI. METHODS: Between 2008 and 2019, we enrolled children with NI who developed pneumonia and were treated in the pediatric ward of Kawasaki Medical School Hospital. We evaluated patient characteristics, the frequency of isolation of multidrug-resistant (MDR) pathogens, and clinical outcomes. RESULTS: MDR pathogens were more frequently isolated from patients receiving tube feeding (TF) and/or with tracheostomy than from patients without these risk factors. Other risk factors, including a history of antibiotic therapy and methicillin-resistant Staphylococcus aureus isolation, recent hospitalization, residence in a nursing home or extended care facility, and low-dose, long-term macrolide therapy, did not significantly affect the frequency of MDR pathogen isolation. In patients receiving TF and/or with tracheostomy, treatment success was achieved in all cases treated with broad-spectrum antibiotics and 72.2% of cases treated with non-broad-spectrum antibiotics (P = 0.007). Conversely, among patients without these risk factors, no such difference was observed. CONCLUSIONS: Our findings indicate that the guideline to select antibiotics for treating pneumonia in children with NI should be simpler and more useful than the current guidelines for adult pneumonia, based on risk factor assessment for MDR pathogens.

Global terrestrial carbon fluxes of 1999-2019 estimated by upscaling eddy covariance data with a random forest.

The terrestrial biosphere is a key player in slowing the accumulation of carbon dioxide in the atmosphere. While quantification of carbon fluxes at global land scale is important for mitigation policy related to climate and carbon, measurements are only available at sites scarcely distributed in the world. This leads to using various methods to upscale site measurements to the whole terrestrial biosphere. This article reports a product obtained by using a Random Forest to upscale terrestrial net ecosystem exchange, gross primary production, and ecosystem respiration from FLUXNET 2015. Our product covers land from -60°S to 80°N with a spatial resolution of 0.1° × 0.1° every 10 days during the period 1999-2019. It was compared with four existing products. A distinguishable feature of our method is using three derived variables of leaf area index to represent plant functional type (PFT) so that measurements from different PFTs can be mixed better by the model. This product can be valuable for the carbon-cycle community to validate terrestrial biosphere models and cross check datasets.

Low prevalence of Chlamydia pneumoniae infections during the Mycoplasma pneumoniae epidemic season: Results of nationwide surveillance in Japan.

OBJECTIVE: Chlamydia pneumoniae and Mycoplasma pneumoniae are both common causes of atypical pneumonia. We conducted an annual national survey of Japanese children to screen them for C. pneumoniae infections during the M. pneumoniae epidemic season. METHODS: Nasopharyngeal swab specimens were collected from children aged 0-15 years with suspected acute lower respiratory tract infection due to atypical pathogens, at 85 medical facilities in Japan from June 2008 to March 2018. Specimens were tested for infection using real-time polymerase chain reaction assays. RESULTS: Of 5002 specimens tested, 1822 (36.5%) were positive for M. pneumoniae alone, 42 (0.8%) were positive for C. pneumoniae alone, and 20 (0.4%) were positive for both organisms. In children with C. pneumoniae infection, the median C. pneumoniae DNA copy number was higher in those with single infections than in those with M. pneumoniae coinfection (p = 0.08); however it did not differ significantly according to whether the children had received antibiotics prior to sample collection (p = 0.34). CONCLUSIONS: The prevalence of C. pneumoniae infection was substantially lower than that of M. pneumoniae infection during the study period. The change in prevalence of C. pneumoniae was not influenced by that of M. pneumoniae. Children with single C. pneumoniae infection are likely to have had C. pneumoniae infection, while those with coinfection are likely to have been C. pneumoniae carriers.

Pulmonary Mycobacterium parascrofulaceum Infection in a Patient with Chronic Progressive Pulmonary Aspergillosis: A Case Report and Literature Review.

A 67-year-old man with a pulmonary cavity was admitted to our hospital. Mycobacterial culture of the bronchoalveolar lavage fluid sample obtained from the right upper pulmonary lesion tested positive for mycobacterium, and sequencing of the 16S rRNA genes, hsp65, and rpoB revealed that the cultured mycobacterium was Mycobacterium parascrofulaceum. Treatment with antimycobacterial agents was ineffective, and repeated culturing of bronchoscopic specimens revealed that the specimens were positive for Aspergillus fumigatus. Combination treatment of antimycobacterial agents and voriconazole improved the lung lesion. This is the first report of a patient with pulmonary M. parascrofulaceum infection complicated with chronic progressive pulmonary aspergillosis.

Impact of MET inhibitors on survival among patients with non-small cell lung cancer harboring MET exon 14 mutations: a retrospective analysis.

OBJECTIVES: Although dramatic responses to MET inhibitors have been reported in patients with MET exon 14 (METex14) mutant non-small cell lung cancer (NSCLC), the impact of these treatments on overall survival in this population is unknown. METHODS: We conducted a multicenter retrospective analysis of patients with METex14 NSCLC to determine if treatment with MET inhibitors impacts median overall survival (mOS). Event-time distributions were estimated using the Kaplan-Meier method and compared with the log-rank test. Multivariable Cox models were fitted to estimate hazard ratios. RESULTS: We identified 148 patients with METex14 NSCLC; the median age was 72; 57% were women and 39% were never smokers. Of the 34 metastatic patients who never received a MET inhibitor, the mOS was 8.1 months; those in this group with concurrent MET amplification had a trend toward worse survival compared to cancers without MET amplification (5.2 months vs 10.5 months, P = 0.06). Of the 27 metastatic patients who received at least one MET inhibitor the mOS was 24.6 months. A model adjusting for receipt of a MET inhibitor as first- or second-line therapy as a time-dependent covariate demonstrated that treatment with a MET inhibitor was associated with a significant prolongation in survival (HR 0.11, 95% CI 0.01-0.92, P = 0.04) compared to patients who did not receive any MET inhibitor. Among 22 patients treated with crizotinib, the median progression-free survival was 7.4 months. DISCUSSION: For patients with METex14 NSCLC, treatment with a MET inhibitor is associated with an improvement in overall survival.

[A Case of Drug-Induced Lung Injury Caused by Kamikihito].

An eighty-nine-year-old Japanese male was admitted to our hospital due to dry cough and dyspnea. Respiratory symptoms appeared soon after an administration of an oriental medicine, Kamikihito for tinnitus. Upon admission, chest computed tomography showed patchy consolidations and ground-glass opacities in the right upper lobe of the lungs, and ground-glass opacities in the bilateral lower lobes. Sulbactam-ampicillin combination (SBT/ABPC, 3 g × 2/day) was started in addition to the change or cessation of several other drugs, including Kamikihito, resulting in respiratory symptoms and chest radiographic exacerbations. Bronchoalveolar lavage fluid obtained from the right S3 showed an increase in the total cell number of lymphocytes. A drug lymphocyte stimulation test (DLST) for Kamikihito was also positive. Kamikihito-induced lung injury was most likely, and treatment with prednisolone (50 mg/day) was started. His respiratory symptoms and chest radiographic findings improved rapidly soon after initiating oral prednisolone. This is the first report of Kamikihito-induced lung injury.

Macrolide-Resistant Mycoplasma pneumoniae Infection, Japan, 2008-2015.

We evaluated isolates obtained from children with Mycoplasma pneumoniae infection throughout Japan during 2008-2015. The highest prevalence of macrolide-resistant M. pneumoniae was 81.6% in 2012, followed by 59.3% in 2014 and 43.6% in 2015. The prevalence of macrolide-resistant M. pneumoniae among children in Japan has decreased.

[Factors Associated with Diagnostic Yield of Endobronchial Ultrasonography with a Guide Sheath for Peripheral Lung Cancer].

Endobronchial ultrasonography with a guide sheath (EBUS-GS) has recently been used for improved diagnostic yields for peripheral pulmonary lesions. This study retrospectively evaluated the factors related to the diagnostic yield of EBUS-GS for peripheral lung cancer. The medical records of 76 patients who had been diagnosed with lung cancer and had undergone bronchoscopy with EBUS-GS in our hospital between August 2014 and September 2015 were reviewed. The total diagnostic ratio of peripheral lung cancer was 71.1%. The following factors of the diagnostic yield were evaluated: location of pulmonary lesion; size; feature; bronchus sign; location of EBUS probe; EBUS detection; number of biopsies performed; procedure time; use of virtual bronchoscopic navigation; use of EBUS-guided transbronchial needle aspiration with EBUS-GS; CT slice thickness; operator's years of medical experience; and specialized training in bronchoscopy at the National Cancer Center. In all cases, lesion size ≧ 20 mm (80.8% vs. 50.0%, P = 0.006), EBUS probe location "within" (90.0% vs. 50.0%, P < 0.001), EBUS detection (80.7% vs. 28.6%, P < 0.001), number of biopsies ≧ 5 (78.0% vs. 47.1%, P = 0.013), and bronchoscopy training (81.6% vs. 60.5%, P = 0.043) significantly contributed to an increase in the diagnostic yield. Following a multivariate analysis, EBUS probe location "within" was found to be the most significant factor affecting the diagnostic yield (odds ratio 14.10, 95% CI 3.53-56.60, P < 0.001), and bronchoscopy training was the second most significant factor (odds ratio 6.93, 95% CI 1.86-25.80, P = 0.004). EBUS probe location "within" and bronchoscopy training are the most important factors for improved diagnostic yield by bronchoscopy with EBUS-GS for peripheral lung cancer.

Cutting edge: The transcription factor Bob1 counteracts B cell activation and regulates miR-146a in B cells.

Mice lacking the lymphocyte-specific transcription factor Bob1 (also called OBF-1 or OCA-B) fail to generate germinal centers and a robust Ig response. We show that peripheral B cells in Bob1(-/-) mice bear characteristics of chronically activated or anergic-like B cells and identify the immunosuppressive microRNA-146a, together with other microRNAs, as novel transcriptional targets of Bob1. The inability to restrict B cell signaling could contribute to the immunodeficient phenotype of these mice and is consistent with an important role for Bob1 in suppressing B cell activation in vivo.

Autosomal-recessive complicated spastic paraplegia with a novel lysosomal trafficking regulator gene mutation.

BACKGROUND: Autosomal-recessive hereditary spastic paraplegias (AR-HSP) consist of a genetically diverse group of neurodegenerative diseases characterised by pyramidal tracts dysfunction. The causative genes for many types of AR-HSP remain elusive. We tried to identify the gene mutation for AR-HSP with cerebellar ataxia and neuropathy. METHODS: This study included two patients in a Japanese family with their parents who are first cousins. Neurological examination and gene analysis were conducted in the two patients and two normal family members. We undertook genome-wide linkage analysis employing single nucleotide polymorphism arrays using the two patients' DNAs and exome sequencing using one patient's sample. RESULTS: We detected a homozygous missense mutation (c.4189T>G, p.F1397V) in the lysosomal trafficking regulator (LYST) gene, which is described as the causative gene for Chédiak-Higashi syndrome (CHS). CHS is a rare autosomal-recessive syndrome characterised by hypopigmentation, severe immune deficiency, a bleeding tendency and progressive neurological dysfunction. This mutation was co-segregated with the disease in the family and was located at well-conserved amino acid. This LYST mutation was not found in 200 Japanese control DNAs. Microscopic observation of peripheral blood in the two patients disclosed large peroxidase-positive granules in both patients' granulocytes, although they had no symptoms of immune deficiency or bleeding tendency. CONCLUSIONS: We diagnosed these patients as having adult CHS presenting spastic paraplegia with cerebellar ataxia and neuropathy. The clinical spectrum of CHS is broader than previously recognised. Adult CHS must be considered in the differential diagnosis of AR-HSP.

Management of refractory Mycoplasma pneumoniae pneumonia: utility of measuring serum lactate dehydrogenase level.

It has been suggested that cytokines are associated with refractory Mycoplasma pneumoniae pneumonia, and steroid administration is reported to be effective in this situation. In order to elucidate the characteristics of refractory M. pneumoniae pneumonia, we analyzed five pediatric patients with refractory M. pneumoniae pneumonia, which was defined as showing prolonged fever and deterioration of clinical and radiological findings despite administration of appropriate antibiotics, compared with 15 pediatric patients with M. pneumoniae pneumonia who responded to treatment promptly (control group). Serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and interleukin (IL)-18 levels were significantly higher in the refractory group than in the control group at the initiation of corticosteroid use (LDH: 571 vs 292 IU/L, p = 0.0129; ALT: 25 vs 11 IU/L, p = 0.0143; AST: 41 vs 26 IU/L, p = 0.0404; IL-18: 579 vs 365 pg/mL, p = 0.0402). Significant correlation was found between serum values of IL-18 and LDH (r(2) = 0.504, p = 0.0433). The administration of corticosteroids to patients in the refractory group resulted in the rapid improvement of symptoms and decrease in serum LDH levels in all patients. A serum LDH level of ≥410 IU/L, which was calculated from receiver operating characteristic curve analysis, seemed to be an appropriate criterion for the initiation of steroid therapy. In conclusion, serum IL-18 and LDH levels can be used as parameters to determine which patients are candidates for corticosteroid therapy. In addition, serum LDH levels seem to be a useful marker for the evaluation of therapeutic efficacy in refractory M. pneumoniae pneumonia.

ERBB4 mutations that disrupt the neuregulin-ErbB4 pathway cause amyotrophic lateral sclerosis type 19.

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disorder characterized by the degeneration of motor neurons and typically results in death within 3-5 years from onset. Familial ALS (FALS) comprises 5%-10% of ALS cases, and the identification of genes associated with FALS is indispensable to elucidating the molecular pathogenesis. We identified a Japanese family affected by late-onset, autosomal-dominant ALS in which mutations in genes known to be associated with FALS were excluded. A whole- genome sequencing and parametric linkage analysis under the assumption of an autosomal-dominant mode of inheritance with incomplete penetrance revealed the mutation c.2780G>A (p. Arg927Gln) in ERBB4. An extensive mutational analysis revealed the same mutation in a Canadian individual with familial ALS and a de novo mutation, c.3823C>T (p. Arg1275Trp), in a Japanese simplex case. These amino acid substitutions involve amino acids highly conserved among species, are predicted as probably damaging, and are located within a tyrosine kinase domain (p. Arg927Gln) or a C-terminal domain (p. Arg1275Trp), both of which mediate essential functions of ErbB4 as a receptor tyrosine kinase. Functional analysis revealed that these mutations led to a reduced autophosphorylation of ErbB4 upon neuregulin-1 (NRG-1) stimulation. Clinical presentations of the individuals with mutations were characterized by the involvement of both upper and lower motor neurons, a lack of obvious cognitive dysfunction, and relatively slow progression. This study indicates that disruption of the neuregulin-ErbB4 pathway is involved in the pathogenesis of ALS and potentially paves the way for the development of innovative therapeutic strategies such using NRGs or their agonists to upregulate ErbB4 functions.

A homozygous mutation of C12orf65 causes spastic paraplegia with optic atrophy and neuropathy (SPG55).

BACKGROUND: Autosomal recessive hereditary spastic paraplegias (AR-HSP) constitute a heterogeneous group of neurodegenerative diseases involving pyramidal tracts dysfunction. The genes responsible for many types of AR-HSPs remain unknown. We attempted to identify the gene responsible for AR-HSP with optic atrophy and neuropathy. METHODS: The present study involved two patients in a consanguineous Japanese family. Neurologic examination and DNA analysis were performed for both patients, and a skin biopsy for one. We performed genome-wide linkage analysis involving single nucleotide polymorphism arrays, copy-number variation analysis, and exome sequencing. To clarify the mitochondrial functional alteration resulting from the identified mutation, we performed immunoblot analysis, mitochondrial protein synthesis assaying, blue native polyacrylamide gel electrophoresis (BN-PAGE) analysis, and respiratory enzyme activity assaying of cultured fibroblasts of the patient and a control. RESULTS: We identified a homozygous nonsense mutation (c.394C>T, p.R132X) in C12orf65 in the two patients in this family. This C12orf65 mutation was not found in 74 Japanese AR-HSP index patients without any mutations in previously known HSP genes. This mutation resulted in marked reduction of mitochondrial protein synthesis, followed by functional and structural defects in respiratory complexes I and IV. CONCLUSIONS: This novel nonsense mutation in C12orf65 could cause AR-HSP with optic atrophy and neuropathy, resulting in a premature stop codon. The truncated C12orf65 protein must lead to a defect in mitochondrial protein synthesis and a reduction in the respiratory complex enzyme activity. Thus, dysfunction of mitochondrial translation could be one of the pathogenic mechanisms underlying HSPs.

Exome sequencing reveals a homozygous SYT14 mutation in adult-onset, autosomal-recessive spinocerebellar ataxia with psychomotor retardation.

Autosomal-recessive cerebellar ataxias (ARCAs) are clinically and genetically heterogeneous disorders associated with diverse neurological and nonneurological features that occur before the age of 20. Currently, mutations in more than 20 genes have been identified, but approximately half of the ARCA patients remain genetically unresolved. In this report, we describe a Japanese family in which two siblings have slow progression of a type of ARCA with psychomotor retardation. Using whole-exome sequencing combined with homozygosity mapping, we identified a homozygous missense mutation in SYT14, encoding synaptotagmin XIV (SYT14). Expression analysis of the mRNA of SYT14 by a TaqMan assay confirmed that SYT14 mRNA was highly expressed in human fetal and adult brain tissue as well as in the mouse brain (especially in the cerebellum). In an in vitro overexpression system, the mutant SYT14 showed intracellular localization different from that of the wild-type. An immunohistochemical analysis clearly showed that SYT14 is specifically localized to Purkinje cells of the cerebellum in humans and mice. Synaptotagmins are associated with exocytosis of secretory vesicles (including synaptic vesicles), indicating that the alteration of the membrane-trafficking machinery by the SYT14 mutation may represent a distinct pathomechanism associated with human neurodegenerative disorders.

Posterior column ataxia with retinitis pigmentosa in a Japanese family with a novel mutation in FLVCR1.

Posterior column ataxia with retinitis pigmentosa (PCARP) is an autosomal recessive neurodegenerative disorder characterized by retinitis pigmentosa and sensory ataxia. Previous studies of PCARP in two families showed a linkage to 1q31-q32. However, detailed investigations on the clinical presentations as well as molecular genetics of PCARP have been limited. Here, we describe a Japanese consanguineous family with PCARP. Two affected siblings suffered from childhood-onset retinitis pigmentosa and slowly progressive sensory ataxia. They also showed mild mental retardation, which has not been described in patients with PCARP. Parametric linkage analysis using high-density single nucleotide polymorphism arrays supported a linkage to the same locus. Target capture and high-throughput sequencing technologies revealed a novel homozygous c.1477G>C (G493R) mutation in FLVCR1, which cosegregated with the disease. A recent study has identified three independent mutations in FLVCR1 in the original and other families. Our results further confirmed that PCARP is caused by mutations in FLVCR1.