Yukiko Nanba

Tottori University, TTJ, Tottori, Japan

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Publications (10)18.23 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: One hundred sixty-four patients with Down syndrome (DS) were confirmed in Tottori Prefecture, Japan, from 1980 to 1999. The sex ratio of 1.52 (99 males and 65 females) was comparable to that reported in previous studies. The live birth prevalence per 1,000 was 1.52 (95% CI: 1.29-1.75) from 1980 to 1999, with a prevalence of 1.34 (95% CI: 1.05-1.63) recorded between 1980 and 1989, and 1.74 (95% CI: 1.37-2.11) between 1990 and 1999. There was no statistically significant change between these two decades (chi(2)-test). Live birth prevalence in these two decades showed a significant increase (chi(2)-test, P < 0.005) compared with that recorded in 1969-1978 in Tottori Prefecture (0.803, 95% CI: 0.677-0.929). Mean ages of mothers at the birth of a DS patient were 31.0 years in 1980-1989 and 32.4 years in 1990-1999 (t-test, no significant difference). Dispersion analysis on the mean age of mothers at birth for patients born between 1969-1978, 1980-1989, and 1990-1999 showed a significant difference (t-test, P < 0.005), while comparing the mean age of mothers in 1969-1978 to those in 1990-1999 also revealed a significant difference (t-test, P < 0.001). Live birth prevalence has increased due to the rise in fertility rates among older women, although maternal age-specific risk rates remain unchanged. The widespread introduction of induced abortion following prenatal diagnosis decreased live birth prevalence of DS largely in European (and a few Asian) countries after 1990, or kept prevalence steady, despite increasing fertility rates among women aged 30 and over. In contrast, all published studies have reported an increase in live birth prevalence of this syndrome in Japan, probably resulting from the fact that prenatal diagnoses are used only exceptionally in this country (due to the negative attitude toward selection of life in Japanese culture).
    American Journal of Medical Genetics Part A 06/2008; 146A(11):1381-6. DOI:10.1002/ajmg.a.32279 · 2.16 Impact Factor
  • Yukiko Nanba · Akira Oka · Kousaku Ohno ·
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    ABSTRACT: We report the clinical course of a case of X-linked lissencephaly with absent corpus callosum and abnormal genitalia (XLAG) exhibiting severe diarrhea. The patient demonstrated lactose intolerance and his intractable seizures were relieved with lactose-free, extensively hydrolyzed whey protein formula. At the age of 2 years while being treated with the antiallergic formula, he was affected with severe diarrhea that resembled watery diarrhea-hypokalemia-acidosis syndrome (WDHA). Administration of octreotide was effective in relieving his secretory diarrhea. Hypoglycemia without hyperinsulinemia was seen during fasting, and plasma vasoactive intestinal polypeptide was not increased when he had WDHA-like diarrhea. Although pancreas of ARX mutant mice revealed an increased number of beta and delta cells, we did not detect the cause of hypoglycemia and secretory diarrhea by pancreatic endocrinology. His urinary findings mimicked the symptoms of Fanconi syndrome, so it was possible that his hyperaldsteronemia affected not only his intestinal tract, but also his renal tubules.
    No to hattatsu. Brain and development 10/2007; 39(5):379-82.
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    ABSTRACT: We present the case of a three-year-old boy who suffered from intractable epilepsy from birth, and who displayed microcephaly and severe developmental delay. Neuroradiological examination revealed the presence of simplified gyri of the cerebral cortex, and increased signal intensity changes in the cerebral white matter on T2-weighted magnetic resonance imaging. A tentative diagnosis of congenital cortical malformation was made, but unexpectedly, the cerebrum, cerebellum, and pons showed a progressive atrophy during the follow-up period. The basal ganglia and thalamus were relatively spared. Investigations could find no evidence of leukodystrophies, metabolic disorders, hereditary brain anomalies, or congenital central nervous infections. This case may represent a novel type of neurodegenerative disease with malformation of cortical development.
    Brain and Development 08/2007; 29(6):383-6. DOI:10.1016/j.braindev.2006.11.008 · 1.88 Impact Factor
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    ABSTRACT: The aim of this study was to assess whether periventricular leukomalacia findings are sufficiently sensitive for predicting the severity of motor prognosis by conventional MRI in the near term. Preterm infants with T1 hyperintensity or cysts in the periventricular regions on term MRI were selected, and their gross motor functions were evaluated at the age of 3 to 5 years. Sixty-two infants had findings of T1 hyperintensity or cysts, and except for infants with these findings, none were diagnosed later as periventricular leukomalacia. All 37 patients with cerebral palsy had periventricular lesions with T1 hyperintensity or cysts in the corona radiata above the posterior limb of the internal capsule on coronal sections. Small T1 hyperintensity lesions were seen on coronal slices and were often difficult to detect on axial slices. All of the 17 infants with T1 hyperintensity findings sparing the corona radiata above the posterior limb of the internal capsule showed normal motor development, irrespective of findings of ventriculomegaly. There was a tendency for the presence of widespread lesions in corona radiata above the posterior limb of the internal capsule to be correlated with the severity of motor handicap. Lesions in the corona radiata above the posterior limb of the internal capsule on a coronal view by term MRI were useful for predicting motor prognosis in preterm infants with periventricular leukomalacia.
    PEDIATRICS 08/2007; 120(1):e10-9. DOI:10.1542/peds.2006-1844 · 5.47 Impact Factor
  • Yukiko Nanba · Akira Oka · Kousaku Ohno ·
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    ABSTRACT: X-linked lissencephaly with absent corpus callosum and abnormal genitalia (XLAG) is caused by a mutation in the ARX gene. We herein report the clinical course of siblings with XLAG with a splicing mutation in ARX. Seizures were observed in utero. Cerebral atrophy was progressive postnatally, and fetal echoencephalography indicated that the atrophy might have started in the prenatal period. They had a typical phenotype, except that the genital abnormality of the younger brother was not remarkable. A portal-systemic shunt that has not been reported in cases with XLAG was seen in the older brother. The siblings had the different complications and severity of disease in spite of possessing the same mutation.
    No to hattatsu. Brain and development 06/2007; 39(3):206-9.
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    ABSTRACT: We report on three acute encephalitis patients with refractory, repetitive partial seizures (AERRPS). All three suffered acute febrile episodes associated with status epilepticus, which necessitated high-dose barbiturate therapy under artificial ventilation for several weeks. Electroencephalography (EEG) revealed a predominance of diffuse epileptiform discharges initially, subsequently developing into periodic bursts of these discharges. Reduction of the barbiturate dosage resulted in clinical and subclinical partial seizures appearing repetitively in clusters. Prolonged fever persisted for 2-3 months, even several weeks after normalization of cell counts in the cerebrospinal fluid. The EEG showed an improvement after resolution of this fever, and seizures became less frequent, although still intractable. Oral administration of high-dose barbiturate and benzodiazepines were partially effective during the acute phase, and a barbiturate dependency, lasting for years, was noted in one patient. Steroid administration was effective in stopping the febrile episodes in one patient, with concurrent improvement in seizure control. Magnetic resonance imaging showed enhancement of bitemporal cortical areas in one patient, and high signal intensity on T2 weighted image in the bilateral claustrum in another patient. Diffuse cortical atrophy appeared within two months after the onset of encephalitis in all patients. The evolution of the seizures and EEG findings suggested a high degree of cortical excitability in AERRPS. In this report, we propose a tentative therapeutic regimen for seizure control in this condition. We also hypothesize that a prolonged inflammatory process exists in the cerebral cortex with AERRPS, and may be pivotal in the epileptogenesis.
    Brain and Development 05/2007; 29(3):147-56. DOI:10.1016/j.braindev.2006.08.005 · 1.88 Impact Factor

  • No to hattatsu. Brain and development 12/2006; 38(6):468-9.
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    ABSTRACT: We recently identified mutations of ARX in nine genotypic males with X-linked lissencephaly with abnormal genitalia (XLAG), and in several female relatives with isolated agenesis of the corpus callosum (ACC). We now report 13 novel and two recurrent mutations of ARX, and one nucleotide change of uncertain significance in 20 genotypic males from 16 families. Most had XLAG, but two had hydranencephaly and abnormal genitalia, and three males from one family had Proud syndrome or ACC with abnormal genitalia. We obtained detailed clinical information on all 29 affected males, including the nine previously reported subjects. Premature termination mutations consisting of large deletions, frameshifts, nonsense mutations, and splice site mutations in exons 1 to 4 caused XLAG or hydranencephaly with abnormal genitalia. Nonconservative missense mutations within the homeobox caused less severe XLAG, while conservative substitution in the homeodomain caused Proud syndrome. A nonconservative missense mutation near the C-terminal aristaless domain caused unusually severe XLAG with microcephaly and mild cerebellar hypoplasia. In addition, several less severe phenotypes without malformations have been reported, including mental retardation with cryptogenic infantile spasms (West syndrome), other seizure types, dystonia or autism, and nonsyndromic mental retardation. The ARX mutations associated with these phenotypes have included polyalanine expansions or duplications, missense mutations, and one deletion of exon 5. Together, the group of phenotypes associated with ARX mutations demonstrates remarkable pleiotropy, but also comprises a nearly continuous series of developmental disorders that begins with hydranencephaly, lissencephaly, and agenesis of the corpus callosum, and ends with a series of overlapping syndromes with apparently normal brain structure.
    Human Mutation 03/2004; 23(2):147-59. DOI:10.1002/humu.10310 · 5.14 Impact Factor
  • Yukiko Nanba · Yoshihiro Maegaki ·
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    ABSTRACT: A 7-year-old female with benign childhood epilepsy with centrotemporal spikes developed epileptic negative myoclonus (ENM) seizures during carbamazepine (CBZ) treatment. She had experienced nocturnal partial seizures since 5 years of age. Interictal electroencephalography demonstrated typical rolandic discharges. Valproate was first initiated at 6 years of age, but the seizures were uncontrollable. Carbamazepine was added and valproate withdrawn. The frequency of partial seizures did not decrease. Moreover, she had brief episodes of tone loss in each or both arms and eye blinking several weeks after CBZ introduction. Unilateral loss of arm tone corresponded to spike-and-wave discharges in the contralateral centrotemporal region, and a loss of tone in arms was associated with bilateral synchronous discharges. Eye blinking was also related to bilateral synchronous discharges and classified as a myoclonic seizure. The ENM and myoclonic seizures disappeared soon after CBZ withdrawal. Therefore the authors concluded that CBZ induced the ENM and myoclonic seizures in this patient. CBZ sometimes induces generalized seizures in the treatment of partial epilepsy and generalized epilepsy. CBZ-induced ENM seizures should be considered when a brief lapse of tone appears during CBZ treatment.
  • Yukiko Nanba · Yoshihiro Maegaki ·

    Pediatric Neurology 09/1999; 21(3). · 1.70 Impact Factor

Publication Stats

269 Citations
18.23 Total Impact Points


  • 2004-2008
    • Tottori University
      • • School of Medicine
      • • Institute of Neurological Sciences
      TTJ, Tottori, Japan
  • 2007
    • National Center for Child Health and Development
      Edo, Tōkyō, Japan