基本情報
研究キーワード
34研究分野
1経歴
1-
2008年 - 2010年
委員歴
7受賞
4-
2019年3月
論文
152-
Endocrine Journal 60(1) 51-55 2013年 査読有りIsolated hypoaldosteronism is a rare and occasionally life-threatening cause of salt wasting in infancy. A 2-month-old Japanese boy of unrelated parents was examined for failure to thrive and poor weight gain. Laboratory findings were hyponatremia, hyperkalemia, high plasma renin and low aldosterone levels. Spot urine analysis by gas chromatography-mass spectrometry (GC-MS) showed that urinary excretion of corticosterone metabolites was elevated. Whereas excretion of 18-hydroxycortricosterone metabolites was within the normal range, excretion of aldosterone metabolites was undetectable. The patient was therefore suspected to have aldosterone synthase deficiency type 1. Sequence analysis of CYP11B2, the gene encoding aldosterone synthase (CYP11B2), showed that the patient was a compound heterozygote for c.168G> A, p.W56X in exon 1 and c.1149C> T, p.R384X in exon 7. p.W56X was inherited from his mother and p.R384X was from his father. Since both alleles contain nonsense mutations, a lack of CYP11B2 activity was speculated to cause his condition. To our knowledge, this is the first Japanese patient in which the molecular basis of aldosterone synthase deficiency type 1 has been clarified. This case also indicates that spot urinary steroid analysis is useful for diagnosis. ©The Japan Endocrine Society.
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Endocrine Journal 60(3) 299-304 2013年 査読有りPseudohypoaldosteronism type 1 (PHA1) is a rare condition characterized by neonatal salt loss with elevated plasma aldosterone and renin levels. Two types of PHA1 have been described: an autosomal recessive systemic form and an autosomal dominant renal form, in which the target organ defect is confined to the renal tubules. The dominant renal form of PHA1 is caused by heterozygous mutations in the NR3C2 gene, which encodes the mineralocorticoid receptor (MR). We determined clinical and biochemical parameters in two familial and four sporadic Japanese patient and analyzed the status of the NR3C2 gene. Failure to thrive was noted in five of the six patients. In one of the familial cases, the mother had an episode of failure to thrive when she was a toddler, but received no medical treatment. NaCl supplementation was discontinued in four of the six patients after they reached one year of age and they have grown normally thereafter. However, in one patient, 9 g/day of salt has been required to maintain serum Na concentration after 1 year of age. Analysis of NR3C2 identified three novel mutations [c. C1951T (p.R651X), c.304_305delGC (p.A102fsX103), c.del 603A (p.T201fsX34)] and one previously reported mutation [c.A2839G (p.947X)]. p.R651X was identified in one familial case and one unrelated sporadic patient. The patient who has been supplemented with large amount of salt was heterozygous for c.del 603A in exon 2. In conclusion, our study expands the spectrum of phenotypes, and characterized mutations of NR3C2 in the renal form of PHA1. © The Japan Endocrine Society.
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Pediatric reports 4 e18 2012年4月 査読有り
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EUROPEAN JOURNAL OF PEDIATRICS 171(2) 401-404 2012年2月 査読有りDent disease is an X-linked tubulopathy mainly caused by inactivating mutations of CLCN5. Features of Bartter syndrome such as hypokalemic metabolic alkalosis are rarely observed in patients with Dent disease. We report a Japanese male patient with Dent disease who also manifested features of Bartter syndrome. At the age of 3 years, he was diagnosed with Dent disease based on low molecular weight proteinuria and hypercalciuria. One year later, he was found to have features of Bartter syndrome, i.e., hypokalemia and metabolic alkalosis, and high levels of plasma renin activity and aldosterone with a normal blood pressure. Despite medical interventions, he developed chronic kidney disease stage 3 at the age of 21 years. To investigate the molecular basis of his disease, CLCN5, KCNJ1, SLC12A1, and CLCkb were analyzed and a novel mutation (Y567X) in CLCN5 was identified. Conclusion: Hypokalemic metabolic alkalosis is a rare manifestation in Dent disease. It is speculated that Dent patients with features of Bartter syndrome are susceptible to progression to renal failure. To study this hypothesis, additional observations and long-term follow-up of such patients are necessary.
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PEDIATRIC DIABETES 13(1) 26-32 2012年2月 査読有りYorifuji T, Fujimaru R, Hosokawa Y, Tamagawa N, Shiozaki M, Aizu K, Jinno K, Maruo Y, Nagasaka H, Tajima T, Kobayashi K, Urakami T. Comprehensive molecular analysis of Japanese patients with pediatric-onset MODY-type diabetes mellitus. Pediatric Diabetes 2012: 13: 26-32. Background: In Asians, mutations in the known maturity-onset diabetes of the young (MODY) genes have been identified in only < 15% of patients. These results were obtained mostly through studies on adult patients. Objective: To investigate the molecular basis of Japanese patients with pediatric-onset MODY-type diabetes. Subjects: Eighty Japanese patients with pediatric-onset MODY-type diabetes. Methods: Mitochondrial 3243A> G mutation was first tested by the polymerase chain reaction restriction fragment length polymorphism analysis for maternally inherited families. Then, all coding exons and exon-intron boundaries of the HNF1A, HNF1B, GCK, and HNF4A genes were amplified from genomic DNA and directly sequenced. Multiplex ligation-dependent probe amplification analysis was also performed to detect whole-exon deletions. Results: After excluding one patient with a mitochondrial 3243A> G, mutations were identified in 38 (48.1%) patients; 18 had GCK mutations, 11 had HNF1A mutations, 3 had HNF4A mutations, and 6 had HNF1B mutations. In patients aged < 8 yr, mutations were detected mostly in GCK at a higher frequency (63.6%). In patients > 9 yr of age, mutations were identified less frequently (45.1%), with HNF1A mutations being the most frequent. A large fraction of mutation-negative patients showed elevated homeostasis model assessment (HOMA) insulin-resistance and normal HOMA-beta indices. Most of the HNF1B mutations were large deletions, and, interestingly, renal cysts were undetectable in two patients with whole-gene deletion of HNF1B. Conclusion: In Japanese patients with pediatric-onset MODY-type diabetes, mutations in known genes were identified at a much higher frequency than previously reported for adult Asians. A fraction of mutation-negative patients presented with insulin-resistance and normal insulin-secretory capacities resembling early-onset type 2 diabetes.
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JOURNAL OF CLINICAL RESEARCH IN PEDIATRIC ENDOCRINOLOGY 4(2) 104-106 2012年 査読有りMaturity-onset diabetes of the young type 3 (MODY3) is caused by heterozygous mutation in the HNF1A gene. Liver adenomatosis has been reported in MODY3 patients. The patient reported in this paper is a Japanese girl who first developed hepatomegaly, fatty liver, and hepatic dysfunction at age 5 years. Liver biopsy demonstrated steatosis and degeneration of hepatocytes. At that time, blood glucose and HbA1c levels were within normal ranges. Elevated HbA1c was noticed 4 years later, but islet cell and glutamic acid decarboxylase antibodies were not detected in the serum. Therefore, MODY3 was suspected and subsequent analysis of the HNF1A gene identified a heterozygous germline splice donor-site mutation in intron 9. MODY3 patients should be screened by non-invasive liver imaging, and careful follow-up of liver disease should be performed.
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日本マス・スクリーニング学会誌 = Journal of Japanese Society for Mass-screening 21(3) 243-246 2011年12月1日
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Three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies.Pediatric reports 3(3) e20 2011年6月30日 査読有りThe clinical phenotype of congenital pituitary hormone deficiency is variable and can be associated with a number of structural abnormalities of the central nervous system. We report three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies. Two of the patients initially showed strabismus and unilateral optic nerve hypoplasia. Thereafter, growth failure became evident, leading to the diagnosis of pituitary hormone deficiency. The other patient had severe congenital hypopituitarism with respiratory distress and hypoglycemia from the first day of life. In addition, he had prolonged jaundice and impaired liver function with bilateral optic nerve hypoplasia. Neuroimaging of the pituitary region in all three patients demonstrated a small anterior pituitary lobe and no pituitary stalk. Our findings indicate that clinical variability of congenital hypopituitarism must be considered. In a patient with ophthalmological symptoms, endocrine evaluation and neuroimaging of the CNS including the pituitary region should be considered.
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ENDOCRINE JOURNAL 58(2) 123-130 2011年2月 査読有りGATA3 is a member of the GATA family of transcription factors. Heterozygous GATA3 abnormalities are associated with hypoparathyroidism, sensorineural deafness, and renal abnormality (HDR syndrome). However, this triad of symptoms does not occur in all HDR patients and other clinical features may be present in some cases. We report the clinical phenotypes and the molecular analysis of GATA 3 in five Japanese HDR patients, including two familial cases. All five patients had hypoparathyroidism and sensorineural deafness, however renal abnormalities were absent in four patients. In addition, two patients with different mutations of GATA3 had female genital tract abnormalities. Sequence analysis of GATA3 demonstrated three novel (R262G, c1063delC and C318) and two reported mutations (c.432insG and c.1051-1G > T). Transient transfection assay using the GATA3 activating reporter system revealed that the transactivating activity of the R262G, c.1063delC, C318S and c.432insG mutants were markedly decreased, indicating that all four mutations are loss-of-function. In conclusion, this study reiterates the clinical variability in HDR syndrome and identifies three novel mutations of GATA3.
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TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 223(2) 113-118 2011年2月 査読有りMaturity-onset diabetes of the young (MODY) is a genetically and clinically heterogeneous type of diabetes mellitus, characterized by early onset (often before 25 years of age) and absence of pancreatic autoimmunity markers. Paired-homeodomain transcription factor 4 (PAX4) functions as a transcriptional repressor and is involved in the differentiation of insulin-secreting beta-cells. Here we identified a novel PAX4 mutation in a Japanese patient with MODY. A 15-year-old, non-obese boy was admitted to our hospital because of polyuria and polydipsia. Laboratory evaluation showed an elevated fasting glucose level; however, islet cell antibodies and glutamic acid decarboxylase antibodies were not detected in the patient's serum. The proband's father had been diagnosed as having type 2 diabetes at age of 30 years. We therefore analyzed several candidate genes of MODY, and identified a novel mutation of a 39-base heterozygous deletion in exon 3 (c.374-412 de139) of PAX4 in the proband and his father. This mutation may cause exon 3 skipping that results in a frameshift, thereby producing a premature stop codon in exon 5. As this mutant PAX4 lacks a part of the homeodomain that is critical for binding to the target gene, this mutant was thought to lose the transcriptional repressor function. As expected, luciferase-reporter assays revealed that the mutant PAX4 could not repress the activities of insulin and glucagon gene promoters, unlike the wild-type PAX4 that repressed the promoter activities. The present study demonstrates that a novel mutation of PAX4 is likely to be associated with diabetes in this Japanese family.
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ENDOCRINE JOURNAL 57(9) 787-792 2010年9月 査読有りFamilial hypocalciuric hypercalcemia (FHH) is a benign disorder with heterozygous inactivating mutations in the calcium-sensing receptor (CASR) gene. The present study describes the identification and functional analysis of a novel CASR gene mutation leading to FHH. The proband is a 33-yr-old woman (Ca 11.0 mg/dL, intact-PTH 68 pg/mL, FECa 0.17 %). Leukocyte DNA was isolated in four family members and a novel heterozygous mutation (D190G, GAT>GGT) in exon 4 of CASR gene was identified by direct sequence analysis. The mutant CASR expression vector was constructed by mutagenesis procedure and its response to Ca(2+) was characterized by transient transfection into human embryonic kidney (HEK) 293 cells and treatment with increasing extracellular Ca(2+) concentrations. HEK cells didn't activate intracellular signaling (MAPK activation) in response to increases of extracellular Ca(2+) concentrations when the mutant receptor was expressed normally at the cell surface. The novel heterozygous mutation (D190G) identified in the present study showed that the reduction of activity of CASR to extracellular Ca(2+) caused FHH in patients and our study demonstrated the importance of Asp-190 participated in response to Ca(2+) in CASR.
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Increased Na reabsorption via the Na-Cl cotransporter in autosomal recessive pseudohypoaldosteronismCLINICAL AND EXPERIMENTAL NEPHROLOGY 14(3) 228-232 2010年6月 査読有りThe autosomal recessive form of pseudohypoaldosteronism type 1 (AR-PHA1) is caused by loss-of-function mutations in the epithelial sodium channel subunit genes and is characterized by a multisystemic and lifelong severe salt-wasting tendency. However, we observed a male AR-PHA1 patient who exhibited less frequent salt wasting with advancing age, despite the cessation of daily salt supplementation. To elucidate the mechanism for the above phenomenon. We evaluated the sodium-reabsorption ability of his distal nephrons (from the distal convoluted tubules to the collecting ducts) and compared it to that of a patient with the dominant form of PHA1 (AD-PHA1) carrying a heterozygous NR3C2 (mineralocorticoid receptor) gene mutation. In addition, immunoblotting of the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) protein was conducted using urine samples from the AR- and AD-PHA1 patients. The levels of sodium reabsorption that occurred via the distal nephrons were almost identical in the two PHA1 patients, despite their different molecular pathogeneses. Immunoblotting showed an increased urinary NCC protein level in the AR-PHA1 patient. Taken together, increased sodium reabsorption via the upregulation of the expression of NCC might have been responsible, at least in part, for the clinical improvement seen in an AR-PHA1 patient.
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CLINICAL ENDOCRINOLOGY 72(2) 272-276 2010年2月 査読有りObjective Gitelman's syndrome, recognized as a variant of Bartter's syndrome, is characterized by hypokalaemic metabolic alkalosis in combination with hypomagnesaemia and hypocalciuria. Overlapping biochemical features in Gitelman's syndrome and Bartter's syndrome has been observed. Here, we investigated the clinical, biochemical, and genetic characteristics of five, chronic, nonhypertensive and hypokalaemic Japanese patients. Methods Serum and urinary electrolytes, plasma renin activity and plasma aldosterone concentration were measured in five patients (four males and one female) with hypokalaemia. Renal clearance tests were performed and distal fractional chloride reabsorption calculated. Finally, mutational analysis of the thiazide-sensitive Na-Cl co-transporter gene was performed. Results Symptoms in patients varied from mild (muscle weakness and numbness) to severe (tetany and foot paralysis). All patients were normotensive or hypotensive, and all had hypokalaemia, hypocalciuria, and hyperreninaemic hyperaldosteronism. However, two male patients had normomagnesaemia, while the remainder was hypomagnesaemic. Renal clearance tests showed that the administration of furosemide decreased distal fractional chloride reabsorption, while thiazide ingestion failed to decrease it. Genetic analysis identified six thiazide-sensitive Na-Cl co-transporter gene mutations, including two novel ones. Therefore, on the basis of the confirmatory renal clearance tests and mutational analysis, a diagnosis of Gitelman's syndrome was made in these patients. Conclusions Two of the five patients diagnosed with Gitelman's syndrome were normomagnesaemic, which is uncommon in this syndrome. Our study indicates that renal clearance tests and mutation analysis can play an important role in diagnosing Gitelman's syndrome more precisely.
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JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM 95(2) 756-764 2010年2月 査読有りContext: Although recent studies have suggested a positive role of OTX2 in pituitary as well as ocular development and function, detailed pituitary phenotypes in OTX2 mutations and OTX2 target genes for pituitary function other than HESX1 and POU1F1 remain to be determined. Objective: We aimed to examine such unresolved issues. Subjects: We studied 94 Japanese patients with various ocular or pituitary abnormalities. Results: We identified heterozygous p.K74fsX103 in case 1, p.A72fsX86 in case 2, p.G188X in two unrelated cases (3 and 4), and a 2,860,561-bp microdeletion involving OTX2 in case 5. Clinical studies revealed isolated GH deficiency in cases 1 and 5; combined pituitary hormone deficiency in case 3; abnormal pituitary structures in cases 1, 3, and 5; and apparently normal pituitary function in cases 2 and 4, together with ocular anomalies in cases 1-5. The wild-type Orthodenticle homeobox 2 (OTX2) protein transactivated the GNRH1 promoter as well as the HESX1, POU1F1, and IRBP (interstitial retinoid-binding protein) promoters, whereas the p.K74fsX103-OTX2 and p.A72fsX86-OTX2 proteins had no transactivation functions and the p.G188X-OTX2 protein had reduced (similar to 50%) transactivation functions for the four promoters, with no dominant-negative effect. cDNA screening identified positive OTX2 expression in the hypothalamus. Conclusions: The results imply that OTX2 mutations are associated with variable pituitary phenotype, with no genotype-phenotype correlations, and that OTX2 can transactivate GNRH1 as well as HESX1 and POU1F1. (J Clin Endocrinol Metab 95: 756-764, 2010)
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Journal of Thyroid Research 2010 619013 2010年 査読有りLoss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH) due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD). Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although 123I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS) gene was normal instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.
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PEDIATRIC RESEARCH 66(3) 312-316 2009年9月 査読有りIn Sapporo city of Japan, neonatal screening for congenital hypothyroidism has used the measurement of free thyroxine (T4) and thyroid-stimulating hormone (TSH) in the filter-paper blood spot. This system has enabled us to identify hyperthyroxinemic diseases. Filter papers were collected from neonatal infants born at 4-6 d of age and neonates who showed elevated free T4 (>4.0 ng/dL, 4 SD above the mean) were studied. Between January 2000 and December 2006, 83,232 newborns were screened. Eleven infants demonstrated persistent hyperthyroxinemia. One patient with slightly elevated free T4 and normal TSH was diagnosed as having familial dysalbuminemic hyperthyroxinemia (FDH). The other two patients with elevated free T4 without suppressed TSH were considered as having resistance of thyroid hormone (RTH), and analysis of thyroid hormone receptor (TR) beta gene confirmed the diagnosis. The remaining eight patients were diagnosed as having neonatal Graves' disease (NGD). Seven of eight pregnant women were treated with antithyroid drug and thus only one unrecognized NGD during pregnancy was detected by screening. Our screening system enables for early awareness of RTH and FDH. Regarding Graves' disease, the benefit of elevated free T4 screening is small, because most pregnant women with Graves' disease were managed. (Pediatr Res 66: 312-316, 2009)
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CLINICAL AND EXPERIMENTAL NEPHROLOGY 13(4) 288-294 2009年8月 査読有りFamilial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive tubular disorder that eventually progresses to renal failure, depending upon the extent of nephrocalcinosis. Its basic pathogenesis is impaired tubular resorption of magnesium and calcium in the thick ascending limb of the loop of Henle (TAL) due to a genetic defect in paracellin-1 (a tight junction protein expressed in TAL). Mutations of the claudin16 gene (CLDN16), formerly called paracellin-1 gene (PCLN-1), have been linked to FHHNC. An extended Egyptian family with more than one member affection by nephrocalcionsis was included and thoroughly investigated in the current study after giving informed consent. Thorough history was taken for polyuria, polydipsia and hypocalcemia symptoms, as well as clinical examination with stress on anthropometric measurements and radiological evaluation for kidneys and bones. Laboratory workup for the differential diagnosis of nephrocalcinosis was done: complete urinalysis, including urinary calcium excretion, urine pH and electrolytes, arterial blood gas (ABG), serum electrolytes (sodium, potassium, calcium, magnesium and phosphorous), renal function tests as well as parathyroid and gonadotropin-sex hormone assay. DNA extraction from peripheral blood leukocytes was done followed by amplification using primers previously described, purification and finally sequencing to analyze each exon of the CLDN16 gene. Two sibs for a consanguineous couple were affected by nephrocalcinosis and showed persistent hypocalcemia, hypercalciuria, nephrocalcinosis with persistently alkaline urine and ocular manifestations in the form of congenital cataracts, high myopia and retinal abnormalities. The elder sib showed genitourinary abnormalities in the form of hypospadias and cryptorchidism. These two sibs had a homozygous two-base deletion in exon 1 of the CLDN16 gene (C. 233_234 del GG; Ins C), causing a frame shift mutation (Arg55 fs); however, their parents were heterozygote carriers for that mutation. The above-mentioned clinical data in the two affected sibs together with the family history of end-stage renal disease associated with nephrocalcinosis and high myopia suggested a diagnosis of FHHNC, which was confirmed for the first time in an Egyptian family by a novel mutation in exon 1 of the CLDN16 gene. Genitourinary associations with FHHNC have not yet been reported in the literature. Here, we will try to highlight the principles of mutation detection based on sequencing with the use of the online NCBI databases, statistics and other search tools.
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ENDOCRINE JOURNAL 56(4) 619-624 2009年7月 査読有りSteroidogenic factor-1 [(SF-1/Ad4BP) (MIM184757)] is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, reproduction, and other metabolic functions. Initially, mutations of SF-1/Ad4BP gene (NR5A1) in humans were identified in two 46, XY female patients with adrenal insufficiency and gonadal dysgenesis. However, recent studies have revealed that heterozygous mutations are more frequently found in 46. XY disorders of sex development (DSD) patients without adrenal failure than in 46, XY DSD patients with adrenal failure. We encountered a Japanese female patient of 46, XY DSD without adrenal failure and identified a novel mutation (V41G) of NR5A1. Functional analysis revealed that this mutant protein could not activate CYP19 promoter, indicating loss of function. In conclusion, we add a novel mutation of NR5A1 in 46, XY DSD patient without adrenal failure.
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JAPANESE JOURNAL OF CLINICAL ONCOLOGY 39(5) 277-283 2009年5月 査読有りOptic pathway/hypothalamic astrocytomas (OPHA) in young children often show accelerated growth and require rather intensive induction chemotherapy. Fifteen children (median age: 3 years) with a large OPHA were treated. All of them presented with progressive disease, and the tumor size was larger than 34 mm. Pilocytic astrocytoma was confirmed histologically in 10 patients. Eleven patients had visual disturbance, six had diencephalic syndrome and four had hydrocephalus. The children received six to eight cycles of cisplatin (20 mg/m(2): days 1-5) and vincristine (1.4 mg/m(2): days 1, 8, 15), every 4 weeks. Objective response was obtained in 11 patients (73%); one complete response, eight partial responses and two minor responses. Although the remaining four cases were evaluated as stable disease, all tumors decreased in volume. All children tolerated the chemotherapy well under careful audiological monitoring. Although the present series was small, this chemotherapy is a useful regimen for induction therapy in children with an aggressive deep-seated pilocytic astrocytoma.
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JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM 94(5) 1723-1731 2009年5月 査読有りContext: Cytochrome P450 oxidoreductase (POR) deficiency is a rare autosomal recessive disorder characterized by skeletal dysplasia, adrenal dysfunction, disorders of sex development (DSD), and maternal virilization during pregnancy. Although multiple studies have been performed for this condition, several matters remain to be clarified, including the presence of manifesting heterozygosity and the underlying factors for clinical variability. Objective: The objective of the study was to examine such unresolved matters by detailed molecular studies and genotype-phenotype correlations. Patients: Thirty-five Japanese patients with POR deficiency participated in the study. Results: Mutation analysis revealed homozygosity for R457H in cases 1-14 (group A), compound heterozygosity for R457H and one apparently null mutation in cases 15-28 (group B), and other combinations of mutations in cases 29-35 (group C). In particular, FISH and RT-PCR sequencing analyses revealed an intragenic microdeletion in one apparent R457H homozygote, transcription failure of apparently normal alleles in three R457H heterozygotes, and nonsense mediated mRNA decay in two frameshift mutation-positive cases examined. Genotype-phenotype correlations indicated that skeletal features were definitely more severe, and adrenal dysfunction, 46, XY DSD, and pubertal failure were somewhat more severe in group B than group A, whereas 46, XX DSD and maternal virilization during pregnancy were similar between two groups. Notable findings also included the contrast between infrequent occurrence of 46, XY DSD and invariable occurrence of 46, XX DSD and pubertal growth pattern in group A mimicking that of aromatase deficiency. Conclusions: The results argue against the heterozygote manifestation and suggest that the residual POR activity reflected by the R457H dosage constitutes the underlying factor for clinical variability in some features but not other features, probably due to the simplicity and complexity of POR-dependent metabolic pathways relevant to each phenotype. (J Clin Endocrinol Metab 94: 1723-1731, 2009)
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JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM 94(1) 314-319 2009年1月 査読有りContext: Orthodenticle homeobox 2 (OTX2) is a transcription factor necessary for ocular and forebrain development. In humans, heterozygous mutations of OTX2 cause severe ocular malformations. However, whether mutations of OTX2 cause pituitary structural abnormalities or combined pituitary hormone deficiency (CPHD) has not been clarified. Objectives: We surveyed the functional consequences of a novel OTX2 mutation that was detected in a patient with anophthalmia and CPHD. Patient: We examined a Japanese patient with growth disturbance, anophthalamia, and severe developmental delay. He showed deficiencies in GH, TSH, LH, FSH, and ACTH. Brain magnetic resonance imaging revealed a small anterior pituitary gland, invisible stalk, ectopic posterior lobe, and Chiari malformation. Results: Sequence analysis of OTX2 demonstrated a heterozygous two bases insertion [S136fsX178 (c.576-577insCT)] in exon 3. The mutant Otx2 protein localized to the nucleus, but did not activate the promoter of the HESX1 and POU1F1 gene, indicating a loss of function mutation. No dominant negative effect in the presence of wild-type Otx2 was observed. Conclusion: This case indicates that the OTX2 mutation is a cause of CPHD. Further study of more patients with OTX2 defects is necessary to clarify the clinical phenotypes and endocrine defects caused by OTX2 mutations. (J Clin Endocrinol Metab 94: 314-319, 2009)
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NEURO-ONCOLOGY 10(5) 725-733 2008年10月 査読有りOptic pathway/hypothalamic pilocytic astrocytomas in children are usually treated with chemotherapy following a surgical biopsy. In this report, we retrospectively considered the role of surgical intervention. In a series of 25 patients without neurofibromatosis type 1, the median age at initial treatment was 3.1 years (range, 0-15 years). Twenty cases were verified by histology, and five cases were diagnosed by MRI findings. Twenty-three patients received chemotherapy. All patients were alive at median follow-up of 66 months. Aims of surgery at the initiation of treatment were biopsy in 12 cases (1 stereotactic and 11 craniotomies) and debulking in 7 cases. The 11 open biopsies revealed pilocytic astrocytoma; however, noticeable complications occurred in five children after the biopsies. Review of preoperative MRIs showed that all had typical findings indicating pilocytic astrocytoma. The open biopsy offered no noteworthy benefit for the patients despite surgical risk and delay of chemotherapy. The extent of the seven resection surgeries was 70% or less removal, and postoperative adjuvant therapy was needed for six of the seven patients. The remaining six children who did not undergo surgery obtained remission with chemotherapy alone. After relapse in nine patients, 15 bulk-reduction surgeries were performed. Surgical resection was not curative in any patient. In five patients, mostly older children, cystic expansion of tumor was partially resected, resulting in additional remission. In conclusion, considering the risk of open surgery and the effectiveness of chemotherapy, the role of surgical intervention is restricted to bulk-reduction surgery only when it is inevitable, especially at relapse after chemotherapy. Neuro-Oncology 10, 725-733, 2008 (Posted to Neuro-Oncology [serial online], Doc. 07-00128, July 8, 2008. URL http://neuro-oncology.dukejournals.org; DOI: 10.1215/15228517-2008-033)
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ホルモンと臨床 56(9) 873-879 2008年9月
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ホルモンと臨床 56(9) 919-924 2008年9月
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Endocrine Journal 55(1) 169-173 2008年 査読有りPseudohypoparathyroidism type Ia (PHP-Ia), one of 4 types of PHP, is a genetic disease characterized by clinical hypoparathyroidism caused by parathyroid hormone (PTH) resistance. In addition, patients with PHP-Ia show resistance to other hormones as well as Albright's hereditary osteodystrophy (AHO), a constellation of features including short stature, obesity, brachydactyly, ectopic ossifications, and/or mental retardation. Hypocalcemia is one of the hallmarks of PHP-Ia, but several PHP-Ia patients have been described to have normocalcemia. We encountered a 10-year-old girl with typical Albright's hereditary osteodystrophy with round face, short stature, brachydactyly, and obesity. Biochemical examination showed normocalcemia and increased PTH levels. Ellsworth-Howard test did not show any responses of urinary cAMP and phosphate. Based on these findings, she was diagnosed as having PHP-Ia with normocalcemia. Sequencing analysis of the GNAS gene identified a heterozygous missense mutation in exon 13 (R385H), which was previously reported in a PHP-Ia patient. The exact reason for her normocalcemia is not determined, but we must recognize heterogeneous biochemical findings even in PHP-Ia.
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Endocrine Journal 55(3) 595-599 2008年 査読有りThe use of octreotide-LAR and cabergoline therapy has shown great promise in adults with acromegaly however, the experience in pediatric patients has rarely been reported. We described a clinical course of a 15-year-old boy of McCune-Albright syndrome (MAS) with pituitary gigantism. At the age of 8 years, a growth hormone (GH) and prolactin (PRL) producing pituitary adenoma was diagnosed at our hospital. He also had multiple fibrous dysplasia, so that he was diagnosed as having MAS. The tumor was partially resected, and GNAS1 gene mutation (R201C) was identified in affected tissues. We introduced octreotide to suppress GH secretion (100 μg × 2/day s.c). During therapy with octreotide, IGF-1 and GH levels could not be suppressed and the patient frequently complained of nausea from octreotide treatment. Therefore, the therapy was changed to monthly injections of octreotide-LAR at the age of 12.3 years and was partially effective. However, as defect of left visual field worsened due to progressive left optic canal stenosis, he underwent second neurological decompression of the left optic nerve at 13.4 years of age. After surgery, in addition to octreotide-LAR, cabergoline (0.25 mg twice a month) was started. This regimen normalized serum levels of GH and IGF-1 however, he showed impaired glucose tolerance and gallstones at 15.7 years of age. Therefore, the dose of octreotide-LAR was reduced to 10 mg and the dose of cabergoline increased. This case demonstrated the difficulty of treating pituitary gigantism due to MAS. The use of octreotide-LAR and cabergoline should be considered even in pediatric patients however, adverse events due to octreotide-LAR must be carefully examined.
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Endocrine Journal 55(3) 557-560 2008年 査読有りWe here report a novel mutation of the thiazide-sensitive Na-Cl cotransporter (TSC) (SLC12A3) gene in a Japanese patient with Gitelman's syndrome (GS). GS is characterized by a renal disorder and is associated with hypokalemia, hypomagnesemia, metabolic alkalosis and hypocalciuria arising from the defective tubular reabsorption of magnesium and potassium. This disease is reportedly caused by mutations in the TSC gene. A 52-year-old man was referred to our hospital because of sleeplessness and tinnitus. He exhibited hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis and hyperreninemie hyperaldosteronism. A renal clearance study revealed that the administration of furosemide decreased chloride reabsorption however, the ingestion of thiazide failed to decrease chloride reabsorption. A diagnosis of GS was made based on the clinical features, laboratory data and renal function test results. Sequencing of the patient's genomic DNA revealed an A to T transition at the initial codon of exon 1 of the TSC gene (c1A> T). Knowledge of this novel mutation may be helpful for understanding the pathophysiology of GS and the function of TSC as well as for providing genetic counseling.
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ENDOCRINE JOURNAL 54(6) 1003-1007 2007年12月 査読有りBartter syndrome (BS) type 1, also referred to antenatal BS, is a genetic tubulopathy with hypokalemic metabolic alkalosis and prenatal onset of polyuria leading to polyhydramnios. It has been shown that BS type I is caused by mutations in the SLC12A1 gene encoding bumetanide-sensitive Na-K-2Cl(-) cotransporter (NKCC2). We had the opportunity to care for two unrelated Japanese patients of BS type 1 with typical manifestations including polyhydramnios, prematurity, hypokalemia, alkalosis, and infantile-onset nephrocalcinosis. Analysis of the SLC12A1 gene demonstrated four novel mutations: N117X, G257S, D792fs and N984fs. N117X mutation is expected to abolish most of the NKCC2 protein, whereas 6257, which is evolutionary conserved, resides in the third transmemebrane domain. The latter two frameshift mutations reside in the intra-cytoplasmic C-terminal domain, which illustrates the importance of this domain for the NKCC2 function. In conclusion, we found four novel SLC12A1 mutations in two BS type 1 patients. Development of effective therapy for hypercalciuria is mandatory to prevent nephrocalcinosis and resultant renal failure.
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ENDOCRINE JOURNAL 54(6) 941-944 2007年12月 査読有りWe encountered a Japanese patient of congenital hypothyroidism with severe cerebellum atrophy. The boy was born after 40 weeks of gestation by normal vaginal delivery from nonconsanguineous parents. There were no abnormal physical findings; however neonatal mass screening for congenital hypothyroidism at 5 days of age demonstrated elevated thyrotropin (TSH) level (15.5 mu U/ml, normal range 0.54-10.0 mu U/ml). He was suspected to have subclinical or mild congenital hypothyroidism (CH). Thus he was treated with L-thyroxine using a regimen that rendered his serum TSH concentration within normal range from 27 days of age. Despite early and adequate treatment, he showed signs of global developmental delay and became gradually hypotonic and exhibited a staggering gait at 3 years of age. Brain magnetic resonance imaging (MRI) demonstrated marked cerebellar atrophy with an intact brainstem. Thyroidal uptake of radioiodide and thyroid gland size were normal, indicating a functional defect only. The relation between congenital hypothyroidism and severe cerebellar atrophy in our patient is not clear. As only a few cases of the combination of CH and cerebellar anomalies have been described previously, cerebellar symptoms in CH should be examined carefully.
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ENDOCRINE JOURNAL 54(4) 637-641 2007年8月 査読有りLIM homeodomain transcription factors regulate many aspects of development in multicellular organisms. LHX4/Lhx4 is a protein that is essential for pituitary development and motor neuron specification in mammals. In human, a heterozygous splicing mutation of the LHX4 gene was reported in a family with combined pituitary hormone deficiencies (CPHD). In addition to CPHD, these patients were characterized by small sella turcica and chiari malformation. Here we report a Japanese patient with CPHD (GH, PRL, TSH, LH, FSH, and ACTH deficiency) due to a novel missense mutation (P366T) of the LHX 4 gene. She showed severe respiratory disease and hypoglycemia soon after birth. Brain MRI demonstrated hypoplastic anterior pituitary, ectopic posterior lobe, a poorly developed sella turcica, and chiari malformation. Sequence analysis of the LHX 4 gene identified a heterozygous missense mutation (P366T) in exon 6, which was present in LIM4 specific domain. Neither of the patient's parents harbored this mutation, indicating de novo mutation.
MISC
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21-水酸化酵素欠損症の診断・治療のガイドライン(2014年改訂版) : 明確になった事項と,まだわかっていないこと (特集 ここがポイント 小児診療ガイドラインの使い方) -- (内分泌・代謝疾患)小児科臨床 70(6) 875-880 2017年6月
共同研究・競争的資金等の研究課題
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日本学術振興会 科学研究費助成事業 2013年4月 - 2016年3月
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日本学術振興会 科学研究費助成事業 2010年 - 2012年
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日本学術振興会 科学研究費助成事業 2008年 - 2010年
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日本学術振興会 科学研究費助成事業 2004年 - 2008年
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日本学術振興会 科学研究費助成事業 2005年 - 2006年