Publications by authors named "Naoki Hamajima"

Type 1 insulin-like growth factor receptor (IGF1R) plays an important role in normal fetal and postnatal growth. Over 30 pathogenic variants of have been identified in patients with short stature. Yet, 20 years after the first report, a variety of phenotypes remain poorly defined.

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Aim: We aimed to evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of noninvasive prenatal testing (NIPT) in high-risk pregnant women.

Methods: Pregnant women who underwent GeneTech NIPT, the most commonly used NIPT in Japan, between January 2015 and March 2019, at Japan NIPT Consortium medical sites were recruited for this study. The exclusion criteria were as follows: pregnant women with missing survey items, multiple pregnancy/vanishing twins, chromosomal abnormalities in the fetus other than the NIPT target disease, and nonreportable NIPT results.

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Abusive head trauma (AHT), commonly known as shaken baby syndrome, is a cranial injury of infants and young children. AHT is an important cause of morbidity and mortality in young children, particularly those younger than 12 months of age. We describe two patients who developed West syndrome, which is a severe epilepsy syndrome composed of the triad of infantile spasms, hypsarrhythmia on electroencephalography, and developmental arrest or regression, possibly attributable to AHT.

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Menkes disease (MD) is a lethal infantile neurodegenerative disorder with X-linked inheritance, characterized by progressive neurodegenerative symptoms caused by pathogenic variants in the ATP7A. Early diagnosis and treatment are important, although the diagnosis is difficult prior to 2 months of age. We present an unusually severe case of MD with skull fractures at the birth and repeated fractures during the neonatal period, with further examinations leading to diagnosis.

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Cornelia de Lange syndrome (CdLS) is a dominant multisystemic malformation syndrome due to mutations in five genes-NIPBL, SMC1A, HDAC8, SMC3, and RAD21. The characteristic facial dysmorphisms include microcephaly, arched eyebrows, synophrys, short nose with depressed bridge and anteverted nares, long philtrum, thin lips, micrognathia, and hypertrichosis. Most affected individuals have intellectual disability, growth deficiency, and upper limb anomalies.

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Article Synopsis
  • A study was conducted to understand why some noninvasive prenatal tests (NIPT) yield nonreportable results by looking at maternal characteristics and related details.
  • Out of 34,626 pregnant women tested, 110 (0.32%) had nonreportable cfDNA results, primarily due to low fetal fraction or altered genomic profiles.
  • The research highlights the importance of classifying nonreportable results to offer clearer information and lessen anxiety for expecting mothers.
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Article Synopsis
  • - The study focused on a 3-year nationwide project in Japan to implement non-invasive prenatal testing (NIPT) for detecting aneuploidy in high-risk pregnant women, with proper genetic counseling provided.
  • - Out of 30,613 tests conducted, only 1.81% were positive for aneuploidy, with high true-positive rates for trisomies, and a very low false-negative rate (0.02%).
  • - The research emphasizes the need for a robust genetic counseling system and a supportive welfare framework to assist women who choose to have children with chromosomal conditions.
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The purpose of this study is to summarize the results from a survey on awareness of genetic counseling for pregnant women who wish to receive non-invasive prenatal testing (NIPT) in Japan. As a component of a clinical study by the Japan NIPT Consortium, genetic counseling was conducted for women who wished to receive NIPT, and a questionnaire concerning both NIPT and genetic counseling was given twice: once after pre-test counseling and again when test results were reported. The responses of 7292 women were analyzed.

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Here, we report a 5-year-old girl with Guillain-Barré syndrome who presented with a chief complaint of pain in the extremities, which was followed by neck stiffness. Bladder dysfunction was found, which required catheterization. Magnetic resonance imaging revealed marked enhancement of the nerve roots in the cauda equina on T1-weighted imaging after gadolinium injection, and nerve conduction studies led to a diagnosis of Guillain-Barré syndrome.

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Objective: The type I insulin-like growth factor I receptor (IGF1R) plays an important role in growth. We aimed to evaluate the detailed mechanism underlying the effect of IGF1R on human growth.

Patients And Methods: We have performed sequence analysis of IGF1R in 55 patients with SGA short stature in Japan, since 2004, and identified novel heterozygous nonsense mutations in 2 patients: an 8-year-old Japanese boy (case 1), with a birthweight of 2228 g (-3·3 SDS) and height of 46 cm (-2·1 SDS), and a 3-year-old Japanese girl (case 2), with a birthweight of 2110 g (-3·0 SDS) and height of 44·3 cm (-2·8 SDS).

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Mutations in the proliferating cell nuclear antigen (PCNA)-binding domain of the CDKN1C gene were recently identified in patients with IMAGe syndrome. However, loss of PCNA binding and suppression of CDKN1C monoubiquitination by IMAGe-associated mutations hardly explain the reduced-growth phenotype characteristic of IMAGe syndrome. We demonstrate here that IMAGe-associated mutations in the CDKN1C gene dramatically increased the protein stability.

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Cerebral white matter injury, usually called periventricular leukomalacia (PVL), is the most common form of injury to preterm infants that is associated with adverse motor and cognitive outcomes. Intrauterine infection may be an important etiological factor in PVL, and premature rupture of the membranes (PROM) can be identified antepartum. In order to investigate the pathophysiology of cerebral white matter injury induced by PROM, the cerebral blood flow (CBF) of the internal carotid artery and the vertebral artery was measured by neck ultrasonography.

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