Functional variants in a TTTG microsatellite on 15q26.1 cause familial nonautoimmune thyroid abnormalities.

Insufficient thyroid hormone production in newborns is referred to as congenital hypothyroidism. Multinodular goiter (MNG), characterized by an enlarged thyroid gland with multiple nodules, is usually seen in adults and is recognized as a separate disorder from congenital hypothyroidism. Here we performed a linkage analysis of a family with both nongoitrous congenital hypothyroidism and MNG and identified a signal at 15q26.1. Follow-up analyses with whole-genome sequencing and genetic screening in congenital hypothyroidism and MNG cohorts showed that changes in a noncoding TTTG microsatellite on 15q26.1 were frequently observed in congenital hypothyroidism (137 in 989) and MNG (3 in 33) compared with controls (3 in 38,722). Characterization of the noncoding variants with epigenomic data and in vitro experiments suggested that the microsatellite is located in a thyroid-specific transcriptional repressor, and its activity is disrupted by the variants. Collectively, we presented genetic evidence linking nongoitrous congenital hypothyroidism and MNG, providing unique insights into thyroid abnormalities.

Genotype-Phenotype Correlations in Thirty Japanese Patients with Congenital Hypothyroidism Attributable to TG Defects.

CONTEXT: Thyroglobulin (Tg), encoded by TG, is essential for thyroid hormone synthesis. TG defects result in congenital hypothyroidism (CH). Most reported patients were born before the introduction of newborn screening (NBS). OBJECTIVE: We aimed to clarify the phenotypic features of patients with TG defects diagnosed and treated since the neonatal period. SUBJECTS AND METHODS: We screened 1061 patients with CH for thirteen CH-related genes and identified thirty patients with TG defects. One patient was diagnosed due to hypothyroidism-related symptoms and the rest were diagnosed via NBS. Patients were divided into two groups according to their genotypes, and clinical characteristics were compared. We evaluated the functionality of the seven missense variants using HEK293 cells. RESULTS: Twenty-seven rare TG variants were detected, including fifteen nonsense, three frameshift, two splice-site, and seven missense variants. Patients were divided into two groups: thirteen patients with biallelic truncating variants and seventeen patients with monoallelic/biallelic missense variants. Patients with missense variants were more likely to develop thyroid enlargement with TSH stimulation than patients with biallelic truncating variants. Patients with biallelic truncating variants invariably required full hormone replacement, whereas patients with missense variants required variable doses of levothyroxine. Loss of function of the seven missense variants was confirmed in vitro. CONCLUSION: To our knowledge, this is the largest investigation on the clinical presentation of TG defects diagnosed in the neonatal period. Patients with missense variants showed relatively mild hypothyroidism with compensative goiter. Patients with only truncating variants showed minimal or no compensative goiter and required full hormone replacement.

Body Roundness Index Is Better Correlated with Insulin Sensitivity than Body Shape Index in Young and Middle-Aged Japanese Persons.

Aims: The present study aimed to clarify the relationships between novel and traditional anthropometric indices and insulin sensitivity (SI) in young and middle-aged Japanese persons with normal glucose tolerance (NGT), and middle-aged Japanese persons with NGT and glucose intolerance. Methods: Plasma glucose and insulin levels were measured in 1270 young (age <40 years) and 2153 middle-aged persons with NGT (n = 1531) and glucose intolerance (n = 622) during a 75-g oral glucose tolerance test. Height (Ht), weight, and waist circumference (WC) were measured. The body mass index (BMI), WC, and the WC/Ht ratio were used as traditional anthropometric indices. A body shape index (ABSI) and the body roundness index (BRI) were calculated as novel indices. Indices of SI (Matsuda index and 1/homeostasis model assessment of insulin resistance) were calculated and compared with anthropometric indices. Results: The ABSI showed a weak correlation with SI indices in all groups. The BRI showed almost the same correlation with SI indices as the BMI, WC, and WC/Ht in all groups. The inverse correlation between each of the anthropometric indices other than ABSI and SI indices was weak in young persons, at 0.16-0.27 (Spearman's ρ values), but strong in middle-aged persons, at 0.38-1.00. On receiver-operating characteristic (ROC) curve analysis for detection of insulin resistance, the ABSI had a lower area under the ROC curve (AUC) than the other anthropometric indices, and the BRI and the WC/Ht ratio showed similar AUCs. The AUCs for the BRI and WC/Ht ratio were the highest in middle-aged men with NGT and glucose intolerance. Conclusions: The BRI, not the ABSI, was better correlated with SI in young and middle-aged Japanese persons. The BRI and WC/Ht ratio were comparable in their correlations with SI and the detection of insulin resistance in the participants of the present study.

Adult Thyroid Outcomes of Congenital Hypothyroidism.

Background: More than 40 years have passed since the introduction of newborn screening (NBS) for congenital hypothyroidism (CH), and many early diagnosed patients have reached adulthood. Their thyroid morphology and function have been little studied. This cross-sectional, observational study was conducted to characterize the thyroid morphology and function of adult CH patients diagnosed in the framework of NBS for CH. Methods: A total of 103 adult CH patients born after 1979 were enrolled at Ito Hospital, Tokyo, Japan, and were classified into Goiter, Normal gland, and Dysgenesis groups based on ultrasonographic findings. For 60 patients, genetic analysis was performed. Thyroid function test results and the proportion of patients with thyroid nodules were compared among the three groups and between 56 female CH patients and 168 non-CH women matched for thyrotropin levels. Results: A significantly low serum free triiodothyronine/free thyroxine ratio (0.22) was observed in the Dysgenesis group. Thyroid nodules were detected in 14.3% (8/56) of female CH patients, more frequently than in non-CH women. Thyroid nodules were detected most frequently in the Goiter group (71%, 10/14). Genetic defects were identified in 89% (8/9) of patients belonging to the Goiter group, including thyroglobulin defect (33%, 3/9), thyroid peroxidase defect (33%, 3/9), and dual oxidase 2 defect (22%, 2/9). Conclusions: Our results suggest that adults with thyroid dysgenesis on levothyroxine replacement therapy have relative triiodothyronine deficiency. Most adults with goitrous CH have genetic dyshormonogenesis. They are at high risk of developing thyroid nodules. Our findings support the current guideline recommendation that CH patients with dyshormonogenesis should undergo periodic thyroid ultrasonography.

Clinical characteristics and efficacy of pioglitazone in a Japanese patient with familial partial lipodystrophy due to peroxisome proliferator-activated receptor γ gene mutation.

Familial partial lipodystrophy (FPLD) 3 is a rare genetic disorder caused by peroxisome proliferator-activated receptor γ gene (PPARG) mutations. Most cases have been reported in Western patients. Here, we describe a first pedigree of FPLD 3 in Japanese. The proband was a 51-year-old woman. She was diagnosed with fatty liver at age 32 years, dyslipidemia at age 37 years, and diabetes mellitus at age 41 years. Her body mass index was 18.5 kg/m2, and body fat percentage was 19.2%. On physical examination, she had less subcutaneous fat in the upper limbs than in other sites. On magnetic resonance imaging, atrophy of subcutaneous adipose tissue was seen in the upper limbs and lower legs. Fasting serum C-peptide immunoreactivity was high (3.4 ng/mL), and the plasma glucose disappearance rate was low (2.07%/min) on an insulin tolerance test, both suggesting apparent insulin resistance. The serum total adiponectin level was low (2.3 µg/mL). Mild fatty liver was seen on abdominal computed tomography. On genetic analysis, a P495L mutation in PPARG was identified. The same mutation was also seen in her father, who had non-obese diabetes mellitus, and FPLD 3 was diagnosed. Modest increases in body fat and serum total adiponectin were seen with pioglitazone treatment. Attention should be paid to avoid overlooking lipodystrophy syndromes even in non-obese diabetic patients if they show features of insulin resistance.

Phenotypic Variability in a Family with Carney Complex Accompanied by a Novel Mutation Involving PRKAR1A.

Carney complex is a rare, autosomal dominant disease accompanied by multiple endocrine neoplastic syndromes. Mutations in the PRKAR1A gene have recently been reported as a cause of Carney complex, but genotype-phenotype correlations vary widely. A 15-year-old Japanese man (Case 1) with short stature visited our hospital with suspected Cushing's syndrome. Biochemical investigations suggested corticotropin-independent Cushing's syndrome. Computed tomography revealed multiple bilateral adrenal tumors, and a two-staged partial adrenalectomy was performed. Pathological findings revealed primary pigmented nodular adrenocortical disease (PPNAD). The patient also exhibited distinctive spotty skin pigmentation. Based on these features, the patient was diagnosed as Carney complex. Cascade screening of family members was performed, and the mother (Case 2) and elder brother (Case 3) were diagnosed as Carney complex. Case 2 showed cardiac myxoma, acromegaly, spotty skin pigmentation, and mammary myxoid fibroadenoma. Case 3 exhibited gigantism, spotty skin pigmentation, and thyroid nodules. Target gene testing in Case 1 and 2 revealed the same novel mutation in PRKAR1A gene (c.503G>T, p.Gly168Val). This mutation was predicted as a pathogenic variant by multiple in silico analyses. Here, we present a family of Carney complex cases with a novel PRKAR1A pathogenic variant exhibiting varied clinical phenotypes within each case. In these cases, some specific phenotypes of Carney complex, such as pigmentary disorders, myxomas, and PPNAD are important as clues for diagnosis and prognostic factors. Clinicians should consider further examination in patients with Carney complex-specific phenotypes.

Diabetic family history in young Japanese persons with normal glucose tolerance associates with k-means clustering of glucose response to oral glucose load, insulinogenic index and Matsuda index.

Aims: The present study aimed to clarify the relationships between diabetic family history (FH), and dysglycemic response to the oral glucose tolerance test (OGTT), insulin secretion, and insulin sensitivity in young Japanese persons with normal glucose tolerance (NGT). Methods: We measured plasma glucose (PG) and immunoreactive insulin levels in 1,309 young Japanese persons (age <40 years) with NGT before and at 30, 60, and 120 min during a 75-g OGTT. Dysglycemia during OGTT was analyzed by k-means clustering analysis. Body mass index (BMI), blood pressure (BP), and lipids were measured. Insulin secretion and sensitivity indices were calculated. Results: PG levels during OGTT were classified by k-means clustering analysis into three groups with stepwise decreases in glucose tolerance even among individuals with NGT. In these clusters, proportion of males, BMI, BP and frequency of FH were higher, and lipid levels were worse, together with decreasing glucose tolerance. Subjects with a diabetic FH showed increases in PG after glucose loading and decreases in insulinogenic index and Matsuda index. Conclusions: Dysglycemic response to OGTT by k-means clustering analysis was associated with FH in young Japanese persons with NGT. FH was also associated with post-loading glucose, insulinogenic index, and Matsuda index.

GWAS of thyroid dysgenesis identifies a risk locus at 2q33.3 linked to regulation of Wnt signaling.

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.

Association between sarcopenia and the severity of diabetic polyneuropathy assessed by nerve conduction studies in Japanese patients with type 2 diabetes mellitus.

AIMS/INTRODUCTION: This study examined the association between the severity of diabetic polyneuropathy (DPN) based on the Baba classification, and sarcopenia and its related factors. MATERIALS AND METHODS: The participants were 261 patients with type 2 diabetes mellitus. DPN was classified as stages 0-4 according to the Baba classification. Sarcopenia was diagnosed based on measurements of the skeletal mass index, grip strength and walking speed, using the Asia Working Group for Sarcopenia 2019 diagnostic criteria. RESULTS: The median age of the participants was 67 years, the proportion of men was 58.6%, the median estimated duration of diabetes was 10 years and the median values for glycated hemoglobin were 10.3%. With regard to DPN, the prevalence of Baba classification stages 0-2 was 90.8% (n = 237), and that of stage 3 or 4 was 9.2% (n = 24). The prevalence of sarcopenia was 19.9%. A trend toward an increase in the frequency of slow walking speed was seen as the stage of DPN progressed. The frequencies of sarcopenia and slow walking speed were higher in the group with the Baba classification stages 3 and 4 than in the group with stages 0-2. On multiple logistic regression analyses, however, DPN was not significantly related to sarcopenia and walking speed. CONCLUSIONS: Although severe DPN might be related to sarcopenia, the frequency of severe DPN is low in the clinical setting, indicating that its contribution to sarcopenia is modest.

Biallelic PROKR2 variants and congenital hypogonadotropic hypogonadism: a case report and a literature review.

Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that causes gonadotropin-releasing hormone (GnRH) deficiency and sexual immaturity. CHH may accompany an abnormal sense of smell (Kallmann syndrome, KS) or no such manifestation (normosmic-CHH). This unusual combination of manifestations is explained by the fact that GnRH neurons originate in the olfactory placode and migrate to the forebrain during embryogenesis. We describe the case of a 31-year-old man with normosmic-CHH, who also had obesity, type 2 diabetes and intellectual disability. He was noticed to have sexual immaturity (small testes with no pubic hair) at age 20 years, when diabetic ketoacidosis developed. Basal and GnRH-stimulated levels of LH (1.0→12.0 IU/L) and FSH (1.9→6.1 IU/L) were detectable but low. The results of the T&T olfactometer and the Alinamin test were definitely normal, with an anatomically normal olfactory system on MRI. Sequencing of 22 CHH-related genes was performed, and compound heterozygous PROKR2 variants were identified: one was a previously known loss-of-function variant (p.Trp178Ser) and the other was a nonsense variant (p.Trp212*). Through a literature review, we found 22 patients (including our patient) with CHH due to biallelic PROKR2 variants, which led us to recognize that most of the patients (86%) were diagnosed with KS. Clinical observations in this study indicate that, even though they have CHH, biallelic PROKR2 variant carriers may have a normal olfactory system as well as presumably normal migration of GnRH neurons. This suggests that the PROK2-PROKR2 pathway affects the function of GnRH neurons after their migration.

Secondary Hypogonadism due to Excessive Ingestion of Isoflavone in a Man.

A 54-year-old man had been drinking approximately 1.2 L of soy milk (equivalent to approximately 310 mg of isoflavones) per day for the previous 3 years. He then developed erectile dysfunction and gynecomastia. On an examination in our department in May, blood tests showed low gonadotropin and testosterone levels, indicative of secondary hypogonadism. He stopped drinking soy milk on his own in June of that year. When he was admitted in August, blood tests showed an improved gonadal function. Secondary hypogonadism caused by the excessive intake of isoflavones in soy milk was diagnosed. In men, an excessive intake of isoflavones may cause feminization and secondary hypogonadism.

Carney Complex Complicated with Primary Pigmented Nodular Adrenocortical Disease without Cushing's Syndrome Recurrence for Five Years after Unilateral Adrenalectomy.

We herein report a case of Carney complex (CNC) complicated with primary pigmented nodular adrenocortical disease (PPNAD) after unilateral adrenalectomy. A 44-year-old woman was admitted to our hospital for PPNAD surgery. She had previously undergone surgery for cardiac myxoma and had a PRKAR1A mutation with no family history of CNC. She had Cushing's signs, but her metabolic abnormalities were mild. Adrenal insufficiency due to poor medication adherence was a concern, so she underwent unilateral adrenalectomy. Cushing's signs improved postoperatively and without recurrence for five years. Treatment plans for PPNAD should be determined based on the patient's condition, medication adherence, and wishes.

Immunohistochemical Expression of Choline Acetyltransferase and Catecholamine-Synthesizing Enzymes in Head-and-Neck and Thoracoabdominal Paragangliomas and Pheochromocytomas.

Paragangliomas (PGLs) are neural-crest-derived, non-epithelial neuroendocrine tumors distributed along the parasympathetic and sympathetic nerves. Head-and-neck PGLs (HNPGLs) have been recognized as nonchromaffin, nonfunctional, parasympathetic tumors. By contrast, thoracoabdominal paragangliomas and pheochromocytomas (PPGLs) are chromaffin, functional, sympathetic tumors. Although HNPGLs and PPGLs have the same histological structure, the zellballen pattern, composed of chief and sustentacular cells surrounded by abundant capillaries, the pathobiological differences between these types of PGLs remain unclarified. To determine the phenotypic features of these PGLs, we performed an immunohistochemical study using specific antibodies against choline acetyltransferase (ChAT), an enzyme involved in acetylcholine synthesis, and enzymes for the catecholamine-synthesis, tyrosine hydroxylase (TH), and dopamine beta-hydroxylase (DBH), in 34 HNPGLs from 31 patients, 12 thoracoabdominal PGLs from 12 patients, and 26 pheochromocytomas from 22 patients. The expression of ChAT, TH, and DBH was 100%, 23%, and 10% in the HNPGLs; 12%, 100%, and 100% in the pheochromocytomas; and 25%, 67%, and 100% in the thoracoabdominal PGLs, respectively. These results designate HNPGLs as acetylcholine-producing parasympathetic tumors, in contrast to PPGLs being catecholamine-producing tumors. The other most frequently used neuroendocrine markers are synaptophysin and chromogranin A expressed 100% and 80%, respectively, and synaptophysin was superior to chromogranin A in HNPGLs. This is the first report of HNPGLs being acetylcholine-producing tumors. Immunohistochemistry of ChAT could be greatly useful for pathologic diagnosis of HNPGL. Whether measurement of acetylcholine levels in the blood or urine could be a tumor marker of HNPGLs should be investigated soon.

Postloading insulinemia is independently associated with arterial stiffness in young Japanese persons.

Associations of arterial stiffness with glucose, insulin, and proinsulin dynamics during the oral glucose tolerance test (OGTT) remain under debate. The aim of this study was to investigate whether plasma glucose (PG), insulin, and proinsulin (Pro) contribute to arterial stiffness, measured by pulse wave velocity (PWV), in young Japanese persons. PG, immunoreactive insulin (IRI), and Pro levels were determined in 1193 young Japanese subjects (<40 years of age) with normal glucose tolerance or nondiabetic hyperglycemia before and at 30, 60, and 120 min during a 75-g OGTT. Participants were divided into two groups according to the median PWV. Background factors, PG, IRI, and Pro levels during the OGTT, and insulin sensitivity (SI) indices in each group were compared. Several multiple regression analysis models were used to evaluate factors contributing to PWV. All IRI and Pro levels before and after glucose loading and the area under the curve (AUC) values for IRI and Pro increased with higher PWV. 1/HOMA-IR and ISI-Matsuda as measures of SI decreased with higher PWV. The IRI AUC and Pro level before glucose loading (Pro0) were independently associated with PWV, in addition to male sex, heart rate, and mean blood pressure. The IRI AUC had a stronger relationship with PWV than Pro0. The IRI AUC had an independent relationship with PWV, whereas both SI indices did not. Postloading insulinemia, but not reduced SI, was independently associated with arterial stiffness in young Japanese persons.

Glucose Effectiveness Decreases in Relationship to a Subtle Worsening of Metabolic Parameters in Young Japanese with Normal Glucose Tolerance.

Background: The aim of the study was to investigate the relationship between glucose effectiveness (Sg) and some metabolic parameters in male and female young Japanese. Methods: We measured plasma glucose and immunoreactive insulin levels in 1309 young Japanese persons (age <40 years) with normal glucose tolerance (NGT) before and at 30, 60, and 120 min during a 75 gram oral glucose tolerance test. We also measured serum adiponectin and high-sensitivity C-reactive protein (hsCRP) levels and oral glucose effectiveness (SgIO), and investigated factors related to SgIO. Results: The results of Spearman correlation analysis revealed that high-density lipoprotein cholesterol (HDL) and adiponectin were positively correlated with SgIO, whereas the proportion of males, body mass index, waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure, triglycerides (TG), and hsCRP were inversely correlated with SgIO. The results of multiple regression analysis indicated negative correlations between SgIO and the proportion of males, WC, and SBP and a positive correlation with HDL. The results of multiple regression analysis excluding WC indicated negative correlations between SgIO and the proportion of males, SBP, and TG and positive correlations with HDL and adiponectin. Conclusions: Sg decreased with a subtle worsening of metabolic parameters, even in young persons with NGT. Decreased Sg may be involved in the development of glucose intolerance in individuals with worse metabolic parameters.

Hereditary pheochromocytoma/paraganglioma syndrome with a novel mutation in the succinate dehydrogenase subunit B gene in a Japanese family: two case reports.

BACKGROUND: Pheochromocytoma and paraganglioma caused by succinate dehydrogenase gene mutations is called hereditary pheochromocytoma/paraganglioma syndrome. In particular, succinate dehydrogenase subunit B mutations are important because they are strongly associated with the malignant behavior of pheochromocytoma and paraganglioma . This is a case report of a family of hereditary pheochromocytoma/paraganglioma syndrome carrying a novel mutation in succinate dehydrogenase subunit B. CASE PRESENTATION: A 19-year-old Japanese woman, whose father died of metastatic paraganglioma, was diagnosed with abdominal paraganglioma, and underwent total resection. Succinate dehydrogenase subunit B genetic testing detected a splice-site mutation, c.424-2delA, in her germline and paraganglioma tissue. Afterwards, the same succinate dehydrogenase subunit B mutation was detected in her father's paraganglioma tissues. In silico analysis predicted the mutation as "disease causing." She is under close follow-up, and no recurrence or metastasis has been observed for 4 years since surgery. CONCLUSIONS: We detected a novel succinate dehydrogenase subunit B mutation, c.424-2delA, in a Japanese family afflicted with hereditary pheochromocytoma/paraganglioma syndrome and found the mutation to be responsible for hereditary pheochromocytoma/paraganglioma syndrome. This case emphasizes the importance of performing genetic testing for patients with pheochromocytoma and paraganglioma suspected of harboring the succinate dehydrogenase subunit B mutation (that is, metastatic, extra-adrenal, multiple, early onset, and family history of pheochromocytoma and paraganglioma) and offer surveillance screening to mutation carriers.

Inactivation of a Frameshift TSH Receptor Variant Val711Phefs*18 is Due to Acquisition of a Hydrophobic Degron.

CONTEXT: Inactivating variants of thyrotropin (thyroid-stimulating hormone; TSH) receptor (TSHR) cause congenital hypothyroidism. More than 60 such variants have been reported so far, most of which were located in the extracellular or transmembrane domain. OBJECTIVE: We report the identification and characterization of a frameshift TSHR variant in the intracytoplasmic C-tail region. METHODS: Sequencing of TSHR was performed in a patient with congenital hypothyroidism. The functionality of the identified variants was assessed by expressing TSHR in HEK293 cells and measuring TSH-dependent activation of the cAMP-response element-luciferase reporter. A series of systematic mutagenesis experiments were performed to characterize the frameshifted amino acid sequence. RESULTS: The proband was heterozygous for a known TSHR variant (p.Arg519His) and a novel frameshift TSHR variant (p.Val711Phefs*18), which removed 54 C-terminal residues and added a 17-amino acid frameshifted sequence. The loss of function of Val711Phefs*18-TSHR was confirmed in vitro, but the function of Val711*-TSHR was found to be normal. Western blotting showed the low protein expression of Val711Phefs*18-TSHR. Fusion of the frameshift sequence to green fluorescent protein or luciferase induced inactivation of them, indicating that the sequence acted as a degron. A systematic mutagenesis study revealed that the density of hydrophobic residues in the frameshift sequence determined the stability. Eight additional frameshift TSHR variants that covered all possible shifted frames in C-tail were created, and another frameshift variant (Thr748Profs*27) with similar effect was found. CONCLUSIONS: We characterized a naturally occurring frameshift TSHR variant located in C-tail, and provided a unique evidence that hydrophobicity in the C-terminal region of the receptor affects protein stability.

Insulin and Proinsulin Dynamics Progressively Deteriorate From Within the Normal Range Toward Impaired Glucose Tolerance.

CONTEXT: Slight elevations in plasma glucose (PG) manifest in advance of diabetes onset, but abnormalities in immunoreactive insulin (IRI), proinsulin (Pro), and adiponectin dynamics during this stage remain poorly understood. OBJECTIVE: The objective of this work is to investigate whether IRI and Pro dynamics become abnormal as glucose tolerance deteriorates from within the normal range toward impaired glucose tolerance (IGT), as well as the relationship between PG, and these dynamics and serum adiponectin levels. DESIGN: A cross-sectional study was designed. SETTING: This study took place at Jichi Medical University in Japan. PARTICIPANTS AND MEASUREMENTS: PG, IRI, and Pro levels were determined in 1311 young Japanese individuals (age < 40 years) with normal or IGT before and at 30, 60, and 120 minutes during a 75-g oral glucose tolerance test. Participants were assigned to 4 groups according to glucose tolerance, and then background factors, adiponectin levels, insulin sensitivity (SI), and insulin secretion (ß) indexes were determined. RESULTS: PG levels as well as IRI and Pro levels 60 and 120 minutes after glucose-loading increased incrementally with deteriorating glucose tolerance. All measures of ß and the SI measure index of insulin sensitivity (ISI)-Matsuda decreased incrementally. Serum adiponectin levels were not significantly different among the glucose tolerance groups, but were independently and negatively correlated with fasting glucose. CONCLUSIONS: Early ß decreased and postloading Pro levels became excessive in a progressive manner as glucose tolerance deteriorated from within the normal range toward IGT.

The Diagnostic Dilemma of GATA3 Immunohistochemistry in Pheochromocytoma and Paraganglioma.

Although GATA3 has been recognized as a useful marker for mammary and urothelial carcinomas, there is large variation in GATA3 expression detected in pheochromocytoma (PC) and paraganglioma (PGL), from 90% to less than 5%. For GATA3 to be a useful diagnostic marker for PCCs/PGLs, the reasons for such discrepancy must be elucidated. Thus, we compared different immunohistochemistry protocols. Three protocols for GATA3 immunohistochemistry, including the use of an automated slide stainer or manual staining with an autoclave and EDTA buffer vs citric acid buffer, were compared. Whole sections of paraffin-embedded tumors, including 30 PCCs, 37 PGLs including 15 head and neck PGLs, 5 retroperitoneal PGLs, 17 urinary bladder PGLs, and 14 neuroblastoma group tumors, were examined and compared with mammary and urothelial carcinoma sections as positive controls. Using the automated slide stainer (Benchmark ULTRA; Ventana Medical Systems) with both buffers, mammary and urothelial carcinomas demonstrated strong GATA3 positivity; however, PCCs/PGLs showed negative or weak heterogeneous staining. Manual staining with an autoclave for antigen retrieval resulted in increased GATA3 immunoreactivity in all head and neck PGLs, all retroperitoneal PGLs, 88% of urinary PGLs, 17% of PCCs, and all neuroblastomas, except for ganglion cells. The normal adrenal medulla stained weakly and heterogeneously. In conclusions, immunohistochemistry for GATA3 in PCCs/PGLs requires stronger antigen retrieval than that in mammary and urinary carcinomas. This finding is especially important to consider if GATA3 is applied for the differential diagnosis of PGLs in unusual sites as supplemental data to the expression of catecholamine-synthesizing enzymes.

Therapeutic efficacy and limitations of potassium iodide for patients newly diagnosed with Graves' disease.

The efficacy of potassium iodide (KI) for Graves' disease (GD) has been reported, although few clinical reports have examined the long-term efficacy of treatment. The objective of this study was to investigate the efficacy and limitations of KI treatment for GD. This study enrolled patients newly diagnosed with mild GD, defined as free thyroxine (FT4) <5.0 ng/dL, between July 2014 and June 2016. KI was started at a dose of 50 mg/day, and if FT4 values did not decrease after initiation of treatment, doses were increased to 100 mg/day. Patients for whom thyroid hormone levels could not be controlled with KI at 100 mg/day were regarded as non-responders. Of the 122 patients (13 males, 109 females) included in this study, 71 (58.2%) responded to KI therapy. The remaining 51 patients (41.8%) were non-responders. The median duration required to judge non-responsiveness was 5.9 months. Multiple logistic regression analysis performed on parameters measured at the initial visit indicated FT4 (odds ratio (OR) 2.19, 95% confidence interval (CI) 1.28-3.75; p = 0.0007) and male sex (OR 3.58, 95%CI 1.04-12.3; p = 0.04) were significantly associated with KI responsiveness. Receiver operating characteristic (ROC) curve analysis of the relationship between FT4 and KI responsiveness indicated an FT4 cut-off of 2.76 ng/dL was optimal for differentiating between responders and non-responders. KI therapy was effective and safe for about 60% of patients with mild GD.