Nationwide comprehensive epidemiological study of rare diseases in Japan using a health insurance claims database.

BACKGROUND: There are more than 7000 rare diseases, most of which have no specific treatment. Disease profiles, such as prevalence and natural history, among the population of a specific country are essential in determining for which disease to research and develop drugs. In Japan, disease profiles of fewer than 2000 rare diseases, called Nanbyo, have been investigated. However, non-Nanbyo rare diseases remain largely uninvestigated. Accordingly, we revealed the prevalence and natural history of rare diseases among the Japanese population. This cross-disease study is the first to analyze rare-disease epidemiology in Japan with high accuracy, disease coverage, and granularity. METHOD: We applied for permission to use the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), which covered 99.9% of public health insurance claims from hospitals and 97.9% from clinics as of May 2015. Then, we obtained 10 years of data on the number of patients of approx. 4500 rare diseases, by sex and age. We translated disease names and established correspondences between rare diseases in NDB and those in Orphanet. Accordingly, we compared the prevalence and natural history between them. RESULTS: About 3000 diseases in NDB are included in Orphanet and other medical databases. The data indicates that even if the Nanbyo systems do not cover a rare disease, its patients survive in many cases. Regarding natural history, genetic diseases tend to be diagnosed later in Japan than in the West. The data shown in this research are available in the Additional file 1 and the website of NanbyoData. CONCLUSIONS: Our research revealed the basic epidemiology and natural history of Japanese patients with some rare diseases using a health insurance claims database. The results imply that the coverage of the present Nanbyo systems is inadequate for rare diseases. Therefore, fundamental reform might be needed to reduce unfairness between rare diseases. Most diseases in Japan follow a tendency of natural history similar to those reported in Orphanet. However, some are detected later, partly because fewer clinical genetic tests are available in Japan than in the West. Finally, we hope that our data and analysis accelerate drug discovery for rare diseases in Japan.

Aortic Coarctation 28 Days after an Arterial Switch Operation in a Neonate.

Aortic coarctation rarely occurs after an arterial switch operation for D-transposition of the great arteries with intact ventricular septum. We report the case of a neonate patient in whom aortic coarctation developed 28 days after an uncomplicated arterial switch operation. Preoperatively, the aorta was noted to have an irregular shape, but there was no pressure gradient across the lesion. The patient underwent successful reoperation to correct the coarctation. We hope that our report raises awareness of a rare early complication after arterial switch operation with intact ventricular septum, and the need to carefully monitor the aortic isthmus in patients who have aortic irregularities, even in the absence of a pressure gradient.

Aortopulmonary collateral arteries: a rare complication after arterial switch operation for transposition of the great arteries.

Collateral vascular arteries from the descending aorta to the pulmonary arteries are uncommon after arterial switch operation. Here, we report the case of a baby girl treated with coil embolization for abnormal blood flow from the descending aorta to the pulmonary arteries after arterial switch operation. A baby girl weighing 1324 g was delivered at 32 weeks 4 days of gestation, and she had D-transposition of the great arteries and a ventricular septal defect. She underwent nitrogen inhalation to reduce pulmonary blood flow before arterial switch operation. After the operation, she presented with left heart failure due to the presence of abnormal blood flow from the descending aorta to the pulmonary arteries, and she was successfully treated with coil embolization. After the treatment, her condition improved dramatically, and she was discharged without any complications.

The analysis of ascending aortic dilatation in patients with a bicuspid aortic valve using the ratio of the diameters of the ascending and descending aorta.

BACKGROUND: A bicuspid aortic valve (BAV) is associated with premature valve dysfunction and abnormalities of the ascending aorta. The aim of our study was to assess the degree of ascending aortic dilatation by measuring the ratio of the dimension of the AAo to that of the descending aorta (DAo) using preoperative computerized tomography (CT). METHODS: A review of our institutional clinical database identified 76 patients undergoing aortic valve replacement (AVR) and 73 control patients undergoing off-pump coronary artery bypass (OPCAB group) between September 2009 and April 2012. RESULTS: There were 17 patients diagnosed with BAV (BAV group), and the remaining 59 patients had a tricuspid aortic valve (TAV group). The ratios of the dimensions of the AAo to that of the DAo (AAo/DAo) for each group were: BAV, 1.58 ± 0.25; TAV, 1.32 ± 0.11; and OPCAB, 1.29 ± 0.12. Interestingly, the AAo/DAo of the BAV group was significantly larger than that of the other groups. CONCLUSIONS: Although progressive AAo dilatation for BAV is well documented, the diameter of the AAo is currently the only estimate of aortic dilatation. In this study, we report that the ratio of the AAo and DAo diameters in patients with BAV can be a new index for assessing the dilatation of the AAo and differentiating the patients with BAV from those with TAV.

Pathophysiology of lung injury induced by common bile duct ligation in mice.

BACKGROUND: Liver dysfunction and cirrhosis affect vasculature in several organ systems and cause impairment of organ functions, thereby increasing morbidity and mortality. Establishment of a mouse model of hepatopulmonary syndrome (HPS) would provide greater insights into the genetic basis of the disease. Our objectives were to establish a mouse model of lung injury after common bile duct ligation (CBDL) and to investigate pulmonary pathogenesis for application in future therapeutic approaches. METHODS: Eight-week-old Balb/c mice were subjected to CBDL. Immunohistochemical analyses and real-time quantitative reverse transcriptional polymerase chain reaction were performed on pulmonary tissues. The presence of HPS markers was detected by western blot and microarray analyses. RESULTS: We observed extensive proliferation of CD31-positive pulmonary vascular endothelial cells at 2 weeks after CBDL and identified 10 upregulated and 9 down-regulated proteins that were associated with angiogenesis. TNF-α and MMP-9 were highly expressed at 3 weeks after CBDL and were less expressed in the lungs of the control group. CONCLUSIONS: We constructed a mouse lung injury model by using CBDL. Contrary to our expectation, lung pathology in our mouse model exhibited differences from that of rat models, and the mechanisms responsible for these differences are unknown. This phenomenon may be explained by contrasting processes related to TNF induction of angiogenic signaling pathways in the inflammatory phase. Thus, we suggest that our mouse model can be applied to pulmonary pathological analyses in the inflammatory phase, i.e., to systemic inflammatory response syndrome, acute lung injury, and multiple organ dysfunction syndrome.

Prenatal exposure to permethrin influences vascular development of fetal brain and adult behavior in mice offspring.

Pyrethroids are one of the most widely used classes of insecticides and show neurotoxic effects that induce oxidative stress in the neonatal rat brain. However, little is still known about effects of prenatal exposure to permethrin on vascular development in fetal brain, central nervous system development, and adult offspring behaviors. In this study, the effects of prenatal exposure to permethrin on the development of cerebral arteries in fetal brains, neurotransmitter in neonatal brains, and locomotor activities in offspring mice were investigated. Permethrin (0, 2, 10, 50, and 75 mg/kg) was orally administered to pregnant females once on gestation day 10.5. The brains of permethrin-treated fetuses showed altered vascular formation involving shortened lengths of vessels, an increased number of small branches, and, in some cases, insufficient fusion of the anterior communicating arteries in the area of circle of Willis. The prenatal exposure to permethrin altered neocortical and hippocampus thickness in the mid brain and significantly increased norepinephrine and dopamine levels at postnatal day 7 mice. For spontaneous behavior, the standing ability test using a viewing jar and open-field tests showed significant decrease of the standing ability and locomotor activity in male mice at 8 or 12 weeks of age, respectively. The results suggest that prenatal exposure to permethrin may affect insufficient development of the brain through alterations of vascular development.

Cardiac sarcoidosis diagnosed by histological assessment of a left ventricular apical core excised for insertion of a left ventricular assist device.

A 58-year-old male with no history of heart disease was admitted to hospital for congestive heart failure due to severe left ventricular dysfunction, and clinically diagnosed with dilated cardiomyopathy. He developed recurrent heart failure requiring several admissions to hospital and was finally referred to our institution with severe congestive heart failure. Despite medical treatment with inotropic agents, his symptoms gradually worsened. A left ventricular assist device (LVAD) was implanted together with mitral and tricuspid valve repair at 22 days after hospitalization. A histological assessment of a left ventricular apical core specimen revealed non-caseating granulomas consistent with cardiac sarcoidosis. The postoperative course was uneventful, and he remains under cardiac rehabilitation while waiting for cardiac transplantation.

Association of variants in genes involved in environmental chemical metabolism and risk of cryptorchidism and hypospadias.

We hypothesized that single-nucleotide polymorphisms (SNPs) of genes involved in environmental endocrine disruptors (EEDs) metabolism might influence the risk of male genital malformations. In this study, we explored for association between 384 SNPs in 15 genes (AHR, AHRR, ARNT, ARNT2, NR1I2, RXRA, RXRB, RXRG, CYP1A1, CYP1A2, CYP1B1, CYP2B6, CYP3A4, CYP17A1 and CYP19A1) and risk of cryptorchidism (CO) and hypospadias (HS) in 334 Japanese (JPN) males (141 controls, 95 CO and 98 HS) and 187 Italian (ITA) males (129 controls and 58 CO). In the JPN study group, five SNPs from ARNT2 (rs2278705 and rs5000770), CYP1A2 (rs2069521), CYP17A1 (rs4919686) and NR1I2 (rs2472680) were significantly associated at both allelic and genotypic levels with risk of at least one genital malformation phenotype. In the ITA study group, two SNPs in AHR (rs3757824) and ARNT2 (rs1020397) were significantly associated with risk of CO. Interaction analysis of the positive SNPs using multifactor dimensionality reduction demonstrated that synergistic interaction between rs2472680, rs4919686 and rs5000770 had 62.81% prediction accuracy for CO (P=0.011) and that between rs2069521 and rs2278705 had 69.98% prediction accuracy for HS (P=0.001) in JPN population. In a combined analysis of JPN and ITA population, the most significant multi-locus association was observed between rs5000770 and rs3757824, which had 65.70% prediction accuracy for CO (P=0.055). Our findings indicate that genetic polymorphisms in genes involved in EED metabolism are associated with risk of CO and HS.

Profiles of Chemical Effects on Cells (pCEC): a toxicogenomics database with a toxicoinformatics system for risk evaluation and toxicity prediction of environmental chemicals.

Profiles of Chemical Effects on Cells (pCEC) is a toxicogenomics database with a system of classifying chemicals that have effects on human health. This database stores and handles gene expression profiling information and categories of toxicity data. Chemicals are classified according to the specific tissues and cells they affect, the gene expression changes they induce, their toxicity and biological functions in this database system. The pCEC system also analyzes relationships between chemicals and the genes they affect in specific tissues and cells. The reason why we developed pCEC is to support decision-making within the context of environmental regulation. Especially, exposure to environmental chemicals during fetal and newborn development may result in a predisposition to various disorders such as cancer, learning disabilities and allergies later in life. The identification and prediction of hazardous chemicals using limited information are important issues in human health risk management. Therefore, various toxicity information including lethal dose 50 (LD50), toxicity pathways and pathological data were loaded into pCEC. pCEC is also a facility for query, analysis and prediction of unknown toxicochemical reaction pathways and biomarkers which are based on toxicoinformatical data mining approaches. This database is available online at http://project.nies.go.jp/eCA/cgi-bin/index.cgi. The current version of the database has information on the hepatotoxicity, reproductive toxicity and embryotoxicity of chemicals.