Published papers

To manage of 21-hydroxylase deficiency (21-OHD), transition medicine from pediatric to adult health care is an important process and requires individually optimized approaches. We sent cross-sectional questionnaire surveys on the current status of transition from pediatric to adult health care in 21-OHD patients to all councillors of the Japanese Society for Pediatric Endocrinology. Many pediatric departments (42.2%) experienced adult 21-OHD patients, and 115 patients (53 males, mean age of 26) in 46 institutions were identified. Whereas almost two-thirds of pediatric endocrinologists regarded the problems of counterparts and cooperation as hindrance of transition medicine, the major reason for continuing to be treated in pediatrics was the patient’s own request. The prevalence of long-term complications including obesity, osteoporosis, infertility, menstrual disorder, gender dysphoria, and testicular adrenal rest tumor were 27.5%, 8.8%, 11.1%, 26.3%, 7.1%, 12.5%, respectively, which is comparable to those of other cohorts previously reported. However, several items, especially infertility and osteoporosis were not checked well enough in adult 21-OHD patients treated in pediatrics. Though 44 of 62 female patients had genital reconstructive surgery, more than half of them were not followed up by gynecologists or pediatric urologists. Quite a few adult 21-OHD patients had been followed up in pediatrics even after coming of age; however, surveillance by pediatric endocrinologists of gynecological, reproductive, and mental problems may be insufficient. Therefore, multidisciplinary approaches should be required in transition medicine for 21-OHD and prerequisite for graduation of pediatrics. Pediatric endocrinologists will need to play a leading role in the development of transition systems.

Growth hormone (GH) deficiency (GHD) in children is a heterogeneous condition that includes several entities of various severities. GH treatment has been affected by various factors. Because comprehensive analyses for Japanese children with GHD over time are scarce, we investigated the baseline characteristics of patients with GHD at the start of GH treatment between 1996 and 2015 using data from the Foundation for Growth Science in Japan. During the registration period, 19,717 subjects were determined to be eligible for GH treatment as GHD. Overall analyses revealed that there were twice the number of male patients as female patients, and the etiology was idiopathic in 91.1%, central nervous system (CNS) tumor at the hypothalamus–pituitary area in 1.7%, CNS tumor distant from the hypothalamus–pituitary area in 0.68%, other tumors in 0.91%, congenital CNS malformations in 0.83%, and other diseases in 1.1% with their specific characteristics. The latest average age, height standard deviation score (SDS), insulin-like growth factor–1 SDS, and proportion of severe GHD at GH treatment initiation were 8.8 years, –2.76, –1.42, and 19.5%, respectively. The proportions of breech delivery and asphyxia gradually decreased, whereas that of caesarean section gradually increased during the registration period with the latest values of 2.2%, 4.9%, and 14.0%, respectively (all analyses: p < 0.0001). In contrast, the proportion of idiopathic GHD with breech delivery seemed to reach the lowest level among those with a birth year before 2000. This study identified the characteristics and changes of patients with GHD over 20 years.

Congenital hypothyroidism due to thyroid dysgenesis (TD), presented as thyroid aplasia, hypoplasia or ectopia, is one of the most prevalent rare diseases with an isolated organ malformation. The pathogenesis of TD is largely unknown, although a genetic predisposition has been suggested. We performed a genome-wide association study (GWAS) with 142 Japanese TD cases and 8380 controls and found a significant locus at 2q33.3 (top single nucleotide polymorphism, rs9789446: P = 4.4 × 10-12), which was replicated in a German patient cohort (P = 0.0056). A subgroup analysis showed that rs9789446 confers a risk for thyroid aplasia (per allele odds ratio = 3.17) and ectopia (3.12) but not for hypoplasia. Comprehensive epigenomic characterization of the 72-kb disease-associated region revealed that it was enriched for active enhancer signatures in human thyroid. Analysis of chromosome conformation capture data showed long-range chromatin interactions of this region with promoters of two genes, FZD5 and CCNYL1, mediating Wnt signaling. Moreover, rs9789446 was found to be a thyroid-specific quantitative trait locus, adding further evidence for a cis-regulatory function of this region in thyroid tissue. Specifically, because the risk rs9789446 allele is associated with increased thyroidal expression of FDZ5 and CCNYL1 and given the recent demonstration of perturbed early thyroid development following overactivation of Wnt signaling in zebrafish embryos, an enhanced Wnt signaling in risk allele carriers provides a biologically plausible TD mechanism. In conclusion, our work found the first risk locus for TD, exemplifying that in rare diseases with relatively low biological complexity, GWAS may provide mechanistic insights even with a small sample size.

Iatrogenic Cushing syndrome (ICS) may be caused by exposure to corticosteroid therapy. We report a case of ICS caused by topical corticosteroids applied to the skin after skin graft surgery. We presume that the development of ICS, in this case, was attributed to a combination of skin barrier disruption, usage of high-potency corticosteroids, broad application area/ large quantity of the corticosteroid, and the extended treatment period. Patients may be at risk for ICS after extensive skin graft surgery if large amounts of very potent topical corticosteroids are applied for an extended period to prevent scar formation or relieve itching.

We review the imaging findings in pediatric thyroid diseases that necessitate prompt diagnosis and timely medical intervention. Congenital hypothyroidism particularly represents a critical pediatric emergency. Ultrasonography stands as the primary modality for accurately assessing thyroid morphology and identifying thyroid dysgenesis.123I-scintigraphy mirrors iodine metabolism and thyroid hormone synthesis, and the concurrent application of perchlorate (perchloride discharge test) elucidates the pathogenesis of thyroid dyshormonogenesis. Nonetheless, radioiodine scintigraphy has seen limited utilization due to the intricacies of pre-test preparation.99mTc-pertechnetate scintigraphy demonstrates high sensitivity in delineating thyroid tissues with minimal radiation exposure, facilitating the diagnosis of thyroid dysgenesis. Additionally, we have included brief insights on the imaging characteristics of central hypothyroidism, thyroiditis, and thyroid masses.

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and mortality rates than essential hypertension. The Japan Endocrine Society (JES) has developed an updated guideline for PA, based on the evidence, especially from Japan. We should preferentially screen hypertensive patients with a high prevalence of PA with aldosterone to renin ratio ≥200 and plasma aldosterone concentrations (PAC) ≥60 pg/mL as a cut-off of positive results. While we should confirm excess aldosterone secretion by one positive confirmatory test, we could bypass patients with typical PA findings. Since PAC became lower due to a change in assay methods from radioimmunoassay to chemiluminescent enzyme immunoassay, borderline ranges were set for screening and confirmatory tests and provisionally designated as positive. We recommend individualized medicine for those in the borderline range for the next step. We recommend evaluating cortisol co-secretion in patients with adrenal macroadenomas. Although we recommend adrenal venous sampling for lateralization before adrenalectomy, we should carefully select patients rather than all patients, and we suggest bypassing in young patients with typical PA findings. A selectivity index ≥5 and a lateralization index >4 after adrenocorticotropic hormone stimulation defines successful catheterization and unilateral subtype diagnosis. We recommend adrenalectomy for unilateral PA and mineralocorticoid receptor antagonists for bilateral PA. Systematic as well as individualized clinical practice is always warranted. This JES guideline 2021 provides updated rational evidence and recommendations for the clinical practice of PA, leading to improved quality of the clinical practice of hypertension.

Hypochondroplasia is an autosomal dominant genetic disorder due to a heterozygous pathogenic variant of the FGFR3 gene. The early diagnosis of hypochondroplasia is necessary, since growth hormone is effective for improving adult height. The genetic test for the FGFR3 gene could help the early diagnosis. The detailed characteristics of FGFR3 genotypes have not been widely investigated in Japan, except for a common pathogenic variant, p.Asn540Lys. This study retrospectively analyzed the FGFR3 genotypes of 35 patients from 30 families with hypochondroplasia (age, range 0–6 years, median 1 year) in Japan. The pathogenic variants of FGFR3 were identified in all the patients: p.Asn540Lys in 23 probands (76.7%), p.Lys650Gln in 2 (6.7%), p.Leu324His in 2 (6.7%), p.Leu324Val, p.Ser351Cys, and p.Lys650Thr in 1 each (3.2%). The median age at diagnosis, height SD score at diagnosis, or the severity of radiologic findings was not significantly different between probands with p.Asn540Lys and those with other variants. Intellectual disability or epilepsy was identified in seven patients with p.Asn540Lys, but none with other variants. The genetic test of FGFR3 can be useful for assessing the potential risk of neurological sequela in children with hypochondroplasia.

We report the first case of classic lipoid congenital adrenal hyperplasia and combined pituitary hormone deficiency. We identified pathogenic variants in the STAR gene: a novel variant of c.126_127delCCinsG, namely, p.Thr44Profs*2 and an already reported variant of c.634C>T, namely, p.Gln212*. The association with combined pituitary hormone deficiency might be just a coincidence.

Objectives: The efficacy of sodium phenylbutyrate (SPB) for hyperammonemia associated with congenital portosystemic shunt (CPSS) remains unknown. We show the effectiveness of oral SPB. Case presentation: Our patient had CPSS with severe hypoplasia of extrahepatic portal veins. At 9 months of age, to assess the efficacy of oral SPB, we evaluated the 24 h fluctuations of venous ammonia levels. In the first two days without SPB, ammonia levels were above 80 μmol/L for half a day. On the third and fourth days, administration of oral SPB three times a day decreased ammonia to acceptable levels, except at midnight. On the fifth day, another oral SPB administration at 8 pm decreased ammonia at midnight. Low levels of branched-chain amino acids, as well as coagulation disturbances, were observed without apparent symptoms. At 12 months of age, he showed normal psychomotor development. Conclusions: Oral SPB may be effective for hyperammonemia associated with CPSS.

The zona fasciculata (zF) in the adrenal cortex contributes to multiple physiological actions through glucocorticoid synthesis. The size, proliferation, and glucocorticoid synthesis characteristics are all female biased, and sexual dimorphism is established by androgen. In this study, transcriptomes were obtained to unveil the sex differentiation mechanism. Interestingly, both the amount of mRNA and the expressions of nearly all genes were higher in females. The expression of Nr5a1, which is essential for steroidogenic cell differentiation, was also female biased. Whole-genome studies demonstrated that NR5A1 regulates nearly all gene expression directly or indirectly. This suggests that androgen-induced global gene suppression is potentially mediated by NR5A1. Using Nr5a1 heterozygous mice, whose adrenal cortex is smaller than the wild type, we demonstrated that the size of skeletal muscles is possibly regulated by glucocorticoid synthesized by zF. Taken together, considering the ubiquitous presence of glucocorticoid receptors, our findings provide a pathway for sex differentiation through glucocorticoid synthesis.

Hypothalamic-pituitary Langerhans cell histiocytosis (HP-LCH) is often associated with arginine vasopressin deficiency (AVD). Patients with AVD caused by HP-LCH rarely develop an impaired osmotic threshold for thirst (OTT). Improvement in OTT among such patients has not been reported in the literature. To our knowledge, here we report the first case of AVD due to HP-LCH in which hypodipsia resolved during chemotherapy. A nine-year-old Japanese girl presented with polydipsia, polyuria, anorexia, and hypernatremia (149.8 mEq/L) and was diagnosed with AVD secondary to HP-LCH. Visual analog scale examination showed a reduced OTT following the water deprivation test. During chemotherapy for Langerhans cell histiocytosis (LCH), serum sodium concentrations became stable between 138.9 and 142.9 mEq/L under the replacement of desmopressin. Repeated visual analog scale examinations showed that she experienced a sense of thirst at a serum sodium concentration of 142.3–144.6 mEq/L, at which she did not experience any thirst prior to the initiation of chemotherapy. These data suggest that chemotherapy directly improved the OTT in our patient. Improved mechanical compression or infiltration of the hypothalamus related to OTT may lead to the recovery of the sense of thirst. This report highlights the potential role of chemotherapy for solitary HP-LCH in patients with hypodipsia and AVD.

Background: The high prevalence of underweight in young women has become a serious health problem in Japan. When and how young women reach a low body mass index (BMI) has not been clarified. Aim: To clarify the characteristics of BMI standard deviation scores (BMI SDS) trajectory of young Japanese women with underweight. Subjects and methods: A total of 601 Japanese female university students aged 20 years were classified into underweight and healthy weight groups. Their school health check-up data were available from the ages of 6 to 20 years. We evaluated the estimated mean values of BMI SDS at each age and differences in BMI SDS (ΔBMI SDS) from 6 years to each age using a mixed-effects model and compared between the two groups at each age. Results: In the underweight group, the BMI SDS at every age (−1.67 to −0.91) and the ΔBMI SDS after 16 years of age (−0.76 to −0.38) were significantly lower than those in the healthy weight group (−0.41 to −0.13, −0.07 to 0.04), respectively. Conclusion: Young Japanese women with underweight have at least two characteristics of BMI SDS trajectory: being constitutionally underweight and shifting their weight status from baseline towards underweight in their late teens.

Recently, whole-exome sequencing (WES) has been used for genetic diagnoses of patients who remain otherwise undiagnosed. WES was performed in 177 Japanese patients with undiagnosed conditions who were referred to the Tokai regional branch of the Initiative on Rare and Undiagnosed Diseases (IRUD) (TOKAI-IRUD). This study included only patients who had not previously received genome-wide testing. Review meetings with specialists in various medical fields were held to evaluate the genetic diagnosis in each case, which was based on the guidelines of the American College of Medical Genetics and Genomics. WES identified diagnostic single-nucleotide variants in 66 patients and copy number variants (CNVs) in 11 patients. Additionally, a patient was diagnosed with Angelman syndrome with a complex clinical phenotype upon detection of a paternally derived uniparental disomy (UPD) [upd(15)pat] wherein the patient carried a homozygous DUOX2 p.E520D variant in the UPD region. Functional analysis confirmed that this DUOX2 variant was a loss-of-function missense substitution and the primary cause of congenital hypothyroidism. A significantly higher proportion of genetic diagnoses was achieved compared to previous reports (44%, 78/177 vs. 24–35%, respectively), probably due to detailed discussions and the higher rate of CNV detection.

Wnt/β-catenin signaling is essential for adrenocortical development. Zinc and ring finger 3 (ZNRF3), an E3 ubiquitin ligase that attenuates Wnt/β-catenin signaling, is negatively regulated by R-spondin via an extracellular domain that is partially encoded by exon 2 of ZNRF3. We recently identified ZNRF3 exon 2 deletions in three individuals with congenital adrenal hypoplasia. ZNRF3 exon 2 deletion impairs R-spondin binding, thereby attenuating β-catenin expression and eventually leading to the development of congenital adrenal hypoplasia. To elucidate the influence of ZNRF3/Znrf3 exon 2 deletion on adrenocortical development, we generated homozygous Znrf3 exon 2 deletion (Znrf3Δ2/Δ2) mice. Whereas the adrenal glands of Znrf3Δ2/Δ2 mice did not show gross morphological changes at birth, moderate hyperplasia of the zona fasciculata (ZF), dispersed medulla arrangement, and a radially spreading zone with macrophage infiltration between the ZF and medulla were observed at 6 weeks of age. 20α-hydroxysteroid dehydrogenase, a marker of the adrenal X-zone, was hardly detected by immunostaining, and gene expression was significantly downregulated. The number of activated β-catenin-positive cells decreased in the zona glomerulosa, consistent with the results of in situ hybridization for Axin2, a Wnt/β-catenin target gene. Plasma ACTH and serum corticosterone levels in Znrf3Δ2/Δ2 mice did not differ significantly from those in wild-type mice. These results show a species-specific difference in the effects of ZNRF3/Znrf3 exon 2 deletions in humans and mice; Znrf3Δ2/Δ2 mice do not develop congenital adrenal hypoplasia but instead exhibit moderate ZF hyperplasia, dispersed medulla arrangement, X-zone dysplasia, and macrophage infiltration occurred in the inner cortex.

Context: Luscan-Lumish syndrome (LLS) is characterized by postnatal overgrowth, obesity, Chiari I malformation, seizures, and intellectual disability. SET domain-containing protein 2 (SETD2) is a histone methyltransferase, where mutations in the gene are associated with the development of LLS. However, mechanisms underlying LLS remain unclear. Case Description: A 20-year-old man was referred to our hospital because of tall stature. His body height was 188.2 cm (+3.18 SD) and he showed obesity with a body mass index of 28.4 kg/m2. He exhibited acral overgrowth, jaw malocclusion, and prognathism, but no history of seizures, intellectual disability, or speech delay. Serum growth hormone (GH), insulin-like growth factor 1 (IGF-1), and nadir GH levels after administration of 75 g oral glucose were within normal range. Pituitary magnetic resonance imaging showed no pituitary adenoma, but Chiari I malformation. Whole exome sequencing analysis of the proband revealed a de novo heterozygous germline mutation in SETD2 (c.236T>A, p.L79H). Skin fibroblasts derived from the patient grew faster than those from his father and the control subject. In addition, these cells showed enhanced tyrosine phosphorylation and transcriptional activity of signal transducer and activator of transcription 5b (STAT5b) and increased IGF-1 expression induced by GH. Conclusion: This is a mild case of LLS with a novel mutation in SETD2 without neurological symptoms. LLS should be differentiated in a patient with gigantism without pituitary tumors. Although further investigation is necessary, this is the first study to suggest the involvement of aberrant GH signaling in the development of LLS.