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Background: The association between pet exposure in infancy, early childhood eczema, and FLG mutations remains unclear., Methods: This was a birth cohort study performed in Tokyo, Japan. The primary outcome was current eczema based on questionnaire responses collected repeatedly from birth to 5 years of age. Generalized estimating equations and generalized linear modeling were used to evaluate the association., Results: Data from 1448 participants were used for analyses. Household dog ownership during gestation, early infancy, and 18 months of age significantly reduced the risk of current eczema. Household cat ownership also reduced the risk of current eczema, albeit without statistical significance. The combined evaluation of children from households with pets, be it cats, dogs or both, the risk of current eczema at 1-5 years of age was lower in those with household pet exposure ownership during gestation (RR = 0.59, 95 % CI 0.45-0.77) and at 6 months (RR = 0.49, 95 % CI 0.36-0.68). , Reduced risks of eczema were also observed at 2-5 (RR = 0.52, 95 % CI 0.37-0.73) and 3-5 years of age (RR = 0.50 95 % CI 0.35-0.74) when the respective household pet ownership were evaluated at 18 months and 3 years of age. These protective associations of reduced risk of eczema were only observed in children without FLG mutations., Conclusions: Household dog and pet (dog, cat, or both) ownership was protective against early childhood eczema in a birth cohort dataset. This protective association was observed only in children without FLG mutations, which should be confirmed in studies with larger cohorts., (Copyright © 2024 Japanese Society of Allergology. Published by Elsevier B.V. All rights reserved.)

Background: Subacute myelo-optico-neuropathy (SMON) is a neurological disorder associated with the administration of clioquinol, particularly at very high doses. Although clioquinol has been used worldwide, there was an outbreak of SMON in the 1950s-1970s in which the majority of cases were in Japan, prompting speculation that the unique genetic background of the Japanese population may have contributed to the development of SMON. Recently, a possible association between loss-of-function polymorphisms in NQO1 and the development of SMON has been reported. In this study, we analyzed the relationship between NQO1 polymorphisms and SMON in Japan., Methods: We analyzed 125 Japanese patients with SMON. NQO1 loss-of-function polymorphisms (rs1800566, rs10517, rs689452, and rs689456) were evaluated. The allele frequency distribution of each polymorphism was compared between the patients and the healthy Japanese individuals (Human Genomic Variation Database and Integrative Japanese Genome Variation Database), as well as our in-house healthy controls., Results: The frequencies of the loss-of-function NQO1 alleles in patients with SMON and the normal control group did not differ significantly., Conclusion: We conclude that known NQO1 polymorphisms are not associated with the development of SMON., (© 2024 The Author(s). Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Genetic variants in HTRA1 are associated with stroke risk. However, the mechanisms mediating this remain largely unknown, as does the full spectrum of phenotypes associated with genetic variation in HTRA1. Here we show that rare HTRA1 variants are linked to ischemic stroke in the UK Biobank and BioBank Japan. Integrating data from biochemical experiments, we next show that variants causing loss of protease function associated with ischemic stroke, coronary artery disease and skeletal traits in the UK Biobank and MyCode cohorts. Moreover, a common variant modulating circulating HTRA1 mRNA and protein levels enhances the risk of ischemic stroke and coronary artery disease while lowering the risk of migraine and macular dystrophy in genome-wide association study, UK Biobank, MyCode and BioBank Japan data. We found no interaction between proxied HTRA1 activity and levels. Our findings demonstrate the role of HTRA1 for cardiovascular diseases and identify two mechanisms as potential targets for therapeutic interventions., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: The association between cytochrome P450 (CYP) 2C19 genotypes and adverse events in patients treated with clopidogrel or prasugrel after percutaneous coronary intervention (PCI) in the Japanese population is unclear.Methods and Results:This study consisted of 1,580 patients whoseCYP2C19genotypes were assessed at Shiga University of Medical Science Hospital, and 193 clopidogrel-treated and 217 prasugrel-treated patients who were followed more than 1 year after receiving PCI were analyzed. Among 1,580 patients, the prevalence of normal, intermediate, and poor metabolizers was 32%, 49%, and 17%, respectively. Overall incidence of the primary outcome, defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, ischemic stroke, or major bleeding was not significantly different between the clopidogrel and prasugrel groups (adjusted hazard ratio [HR] 1.98, 95% confidence interval [CI] 0.85-4.61, P=0.12). Among patients with theCYP2C19loss-of-function (LOF) allele, however, the incidence of the primary outcome was significantly higher in the clopidogrel group (adjusted HR 3.19, 95% CI 1.10-9.24, P=0.03), whereas no difference was observed among patients without theCYP2C19LOF allele (adjusted HR 0.67, 95% CI 0.14-3.26, P=0.62)., Conclusions: Among patients with theCYP2C19LOF allele, the use of clopidogrel was significantly associated with increased adverse events. Thus, further investigation is needed to establish the practical use ofCYP2C19genotyping.

Monocarboxylate transporter 8 (MCT8) facilitates T3 uptake into cells. Mutations in MCT8 lead to Allan-Herndon-Dudley syndrome (AHDS), which is characterized by severe psychomotor retardation and abnormal thyroid hormone profile. Nine uncharacterized MCT8 mutations in Japanese patients with severe neurocognitive impairment and elevated serum T3 levels were studied regarding the transport of T3. Human MCT8 (hMCT8) function was studied in wild-type (WT) or mutant hMCT8-transfected human placental choriocarcinoma cells (JEG3) by visualizing the locations of the proteins in the cells, detecting specific proteins, and measuring T3 uptake. We identified 6 missense (p.Arg445Ser, p.Asp498Asn, p.Gly276Arg, p.Gly196Glu, p.Gly401Arg, and p.Gly312Arg), 2 frameshift (p.Arg355Profs*64 and p.Tyr550Serfs*17), and 1 deletion (p.Pro561del) mutation(s) in the hMCT8 gene. All patients exhibited clinical characteristics of AHDS with high free T3, low-normal free T4, and normal-elevated TSH levels. All tested mutants were expressed at the protein level, except p.Arg355Profs*64 and p.Tyr550Serfs*17, which were truncated, and were inactive in T3 uptake, excluding p.Arg445Ser and p.Pro561del mutants, compared with WT-hMCT8. Immunocytochemistry revealed plasma membrane localization of p.Arg445Ser and p.Pro561del mutants similar with WT-hMCT8. The other mutants failed to localize in significant amount(s) in the plasma membrane and instead localized in the cytoplasm. These data indicate that p.Arg445Ser and p.Pro561del mutants preserve residual function, whereas p.Asp498Asn, p.Gly276Arg, p.Gly196Glu, p.Gly401Arg, p.Gly312Arg, p.Arg355Profs*64, and p.Tyr550Serfs*17 mutants lack function. These findings suggest that the mutations in MCT8 cause loss of function by reducing protein expression, impairing trafficking of protein to plasma membrane, and disrupting substrate channel.

We report a patient with thrombocytopenia from a Japanese family with hemophilia A spanning four generations. Various etiologies of thrombocytopenia, including genetic, immunological, and hematopoietic abnormalities, determine the prognosis for this disease. In this study, we identified a novel heterozygous mutation in a gene encoding cytochrome c, somatic (CYCS, MIM123970) using whole exome sequencing. This variant (c.301_303del:p.Lys101del) is located in the α-helix of the cytochrome c (CYCS) C-terminal domain. In silico structural analysis suggested that this mutation results in protein folding instability. CYCS is one of the key factors regulating the intrinsic apoptotic pathway and the mitochondrial respiratory chain. Using the yeast model system, we clearly demonstrated that this one amino acid deletion (in-frame) resulted in significantly reduced cytochrome c protein expression and functional defects in the mitochondrial respiratory chain, indicating that the loss of function of cytochrome c underlies thrombocytopenia. The clinical features of known CYCS variants have been reported to be confined to mild or asymptomatic thrombocytopenia, as was observed for the patient in our study. This study clearly demonstrates that thrombocytopenia can result from CYCS loss-of-function variants., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

RNF43 mutations are frequently detected in colorectal cancer cells and lead to a loss of function of the ubiquitin E3 ligase. Here, we investigated the clinical significance of RNF43 mutations in a large Japanese cohort and the role of RNF43 at various stages of colorectal cancer development and progression. Mutation analysis of the RNF43 gene locus with pyrosequencing technology detected RNF43 hotspot mutations in one (0.88%) of 113 colorectal polyp cases and in 30 (6.45%) of 465 colorectal cancer cases. Moreover, patients with colorectal cancer harbouring mutated RNF43 experienced a higher recurrence rate than those harbouring non-mutated RNF43. In addition, the growth of RNF43 wild-type colorectal cancer cell lines was significantly increased by RNF43 silencing. We generated Rnf43 knockout mice in a C57BL/6 N background by using the CRISPR-Cas9 system. Although intestinal organoids from Rnf43 knockout mice did not show continuous growth in the absence of R-spondin, an azoxymethane/dextran sodium sulphate mouse model demonstrated that tumours were markedly larger in Rnf43 knockout mice than in wild-type mice. These findings provide evidence that Wnt signalling activation by RNF43 mutations during the tumourigenic stage enhances tumour growth and promotes a high recurrence rate in colorectal cancer patients. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)