Clinical Pediatric Endocrinology
Online ISSN : 1347-7358
Print ISSN : 0918-5739
ISSN-L : 0918-5739
Advance online publication
Displaying 1-6 of 6 articles from this issue
  • Tomoyo Itonaga, Yukihiro Hasegawa, Shinji Higuchi, Mari Satoh, Hirotak ...
    Article ID: 2022-0016
    Published: 2022
    Advance online publication: November 18, 2022

    Several excellent guidelines and expert opinions on congenital hypothyroidism (CH) are currently available. Nonetheless, these guidelines do not address several issues related to CH in detail. In this article, the authors chose the following seven clinical issues that they felt were especially deserving of closer scrutiny in the hope that drawing attention to them through discussion would help pediatric endocrinologists and promote further interest in the treatment of CH.
    1. How high should the levothyroxine (L-T4) dose be for initial treatment of severe and permanent CH?
    2. What is the optimal method for monitoring treatment of severe CH?
    3. At what level does maternal iodine intake during pregnancy affect fetal and neonatal thyroid function?
    4. Does serum thyroglobulin differ between patients with a dual oxidase 2 (DUOX2) variants and those with excess iodine?
    5. Who qualifies for a genetic diagnosis?
    6. What is the best index for distinguishing transient and permanent CH?
    7. Is there any cancer risk associated with CH?
    The authors discussed these topics and jointly edited the manuscript to improve the understanding of CH and related issues.

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  • Megumi Iwahashi-Odano, Miyuki Kitamura, Satoshi Narumi
    Article ID: 2022-0061
    Published: 2022
    Advance online publication: November 02, 2022

    Paired box 8 (PAX8) mutations are an established genetic cause of congenital hypothyroidism (CH). The majority of these mutations are found in the protein-coding exons of the gene. The proband, a 3-yr-old girl, had tetralogy of Fallot and polydactyly soon after birth. She was diagnosed with CH in the newborn screening for CH. She had a high serum TSH level (239 mU/L) and low free T4 level (0.7 ng/dL). Ultrasonography revealed thyroid hypoplasia. We performed array comparative genomic hybridization because the patient exhibited a variety of symptoms across multiple organ systems. The analysis revealed a novel heterozygous deletion that spanned a 15.2 Mb region in 2q12.3q14.3 (GRCh37; chr2:109,568,260–124,779,449). There were 71 protein-coding genes in this region, including two genes (PAX8 and GLI2) associated with congenital endocrine disorders. The common clinical features of the two previously reported patients with a total PAX8 deletion and our case were CH, short stature and intellectual disability, but the severity of hypothyroidism and other clinical features were variable. In conclusion, we describe a syndromic CH patient with a novel 2q12.3q14.3 deletion involving PAX8. Patients with CH, whose unifying diagnosis is not obvious, could have a genomic deletion involving PAX8.

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  • Haruka Ejiri, Mahiro Asano, Nana Nakahata, Satoshi Suzuki, Ayako Sato, ...
    Article ID: 2022-0057
    Published: 2022
    Advance online publication: October 15, 2022

    We previously described the thyroid volume, which was calculated by measuring the thyroid width, thickness, and longitudinal length using ultrasonography, in children and adolescents. We have proposed a simplified method for quantitatively assessing the thyroid size, to overcome the inaccuracy and challenges in measuring the longitudinal length of the thyroid. Based on measurements of 317,847 (girls: 156,913, boys: 160,934) children and adolescents, we calculated sex-specific means and standard deviations of thyroid width and thickness, and of the cross-sectional area computed by multiplying them, for every age and 0.1 m2 of body surface area, after ensuring normal distribution with Box–Cox transformation. Multivariate regression analysis revealed that female sex, age, and body surface area were independently associated with areas of each thyroid lobe. Our novel method may be useful in quantitatively assessing the thyroid size, and appropriately diagnosing pathological conditions, such as hypoplasia, atrophy, and enlargement of the thyroid gland, in children and adolescents.

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  • Noboru Uchida, Yusuke Mizuno, Shohei Seno, Yutaro Koyama, Tsutomu Taka ...
    Article ID: 2022-0060
    Published: 2022
    Advance online publication: October 07, 2022
  • Yu Kimizuka, Takeshi Sato, Satsuki Nakano, Tomohiro Ishii, Tomonobu Ha ...
    Article ID: 2022-0058
    Published: 2022
    Advance online publication: September 28, 2022
  • Toshimi Michigami
    Article ID: 2022-0053
    Published: 2022
    Advance online publication: September 19, 2022

    Osteocytes are dendritic-shaped cells embedded in the bone matrix and are terminally differentiated from osteoblasts. Inaccessibility due to their location has hindered the understanding of the molecular functions of osteocytes. However, scientific advances in the past few decades have revealed that osteocytes play critical roles in bone and mineral metabolism through their paracrine and endocrine functions. Sclerostin produced by osteocytes regulates bone formation and resorption by inhibiting Wnt/β-catenin signaling in osteoblast-lineage cells. Receptor activator of nuclear factor κ B ligand (RANKL) derived from osteocytes is essential for osteoclastogenesis and osteoclast activation during postnatal life. Osteocytes also secrete fibroblast growth factor 23 (FGF23), an endocrine FGF that regulates phosphate metabolism mainly by increasing phosphate excretion and decreasing 1, 25-dihydroxyvitamin D production in the kidneys. The regulation of FGF23 production in osteocytes is complex and multifactorial, involving many local and systemic regulators. Antibodies against sclerostin, RANKL, and FGF23 have emerged as new strategies for the treatment of metabolic bone diseases. Improved undrstanding of the paracrine and endocrine functions of osteocytes will provide insight into future therapeutic options.

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