A case of osteogenesis imperfecta caused by a COL1A1 variant, coexisting with pituitary stalk interruption syndrome.

Osteogenesis imperfecta (OI) is a rare hereditary bone fragility disorder that affects 6-7 per 100,000 populations, and pituitary stalk interruption syndrome (PSIS) is a rare congenital defect with varying degrees of pituitary hormone deficiency, affecting approximately 0.5 in every 100,000 births. Currently, only two cases of these complications have been reported. A 46-year-old male who had experienced more than 20 fractures (peripheral and vertebral) during adolescence visited our hospital for close examination. He presented with blue sclerae and long bone deformations. We suspected OI because his mother and sister, who were being treated for osteoporosis, also had blue sclerae. Genetic testing identified a heterozygous variant (c.757C > T, p.Arg253Ter) in the COL1A1 gene, leading to the diagnosis of OI. His mother and sister also had the same variant. Considering that he underwent GH replacement therapy for his short stature during his childhood, his pituitary hormone levels were also evaluated to know if GH deficiency impacted low bone density; hypopituitarism was then suspected. The pituitary function test results led to the diagnoses of hypothalamic GH deficiency, hypogonadism, hypothyroidism, and hypoadrenocorticism. Furthermore, magnetic resonance imaging showed anterior pituitary atrophy, pituitary stalk loss, and ectopic posterior pituitary, leading to the diagnosis of PSIS. The combination of OI and hypopituitarism may have caused further bone fragility. Therefore, although rare, clinicians should keep in mind that patients with OI can possibly have concomitant pituitary insufficiency, which can lead to developmental and growth retardation.

Prediction of long-term biochemical cure in patients with unilateral primary hyperaldosteronism treated surgically based on the early post-operative plasma aldosterone value.

In 2017, the Primary Aldosteronism Surgical Outcome (PASO) investigators proposed consensus criteria for clinical and biochemical outcomes. However, 6 to 12 months need to pass in order to assess for the outcome in patients who have undergone surgery for the management of primary hyperaldosteronism. This study aims to evaluate the post-operative biochemical and clinical outcomes of primary aldosteronism (PA) on the basis of the laboratory findings obtained within 10 days after surgery. We retrospectively studied 59 consecutive patients with unilateral PA who underwent adrenalectomy and were assessed for plasma aldosterone concentration (PAC) and plasma renin activity both at the initial assessment (1-10 days after surgery) and the final assessment (6-12 months after surgery). When comparing the complete biochemical success group (n = 51) and the partial or absent biochemical success group (n = 8), the median post-operative PAC at the initial assessment was significantly greater in the partial or absent biochemical success group (12.7 ng/dL; interquartile range [IQR], 10.6-14.5) than that in the complete biochemical success group (6.3 ng/dL; IQR, 5.0-7.9) (p < 0.001), while no significant differences were observed in other factors. The receiver operating characteristic curves of post-operative PAC at the initial assessment, which was used to predict biochemical outcomes, indicated that 8.1 ng/dL is the optimal PAC cut-off for biochemical success (sensitivity, 76.5%; specificity, 100%). Low post-operative PAC at the initial assessment may predict the biochemical cure of PA.

Development of Human Adrenocortical Adenoma (HAA1) Cell Line from Zona Reticularis.

The human adrenal cortex is composed of distinct zones that are the main source of steroid hormone production. The mechanism of adrenocortical cell differentiation into several functionally organized populations with distinctive identities remains poorly understood. Human adrenal disease has been difficult to study, in part due to the absence of cultured cell lines that faithfully represent adrenal cell precursors in the early stages of transformation. Here, Human Adrenocortical Adenoma (HAA1) cell line derived from a patient's macronodular adrenocortical hyperplasia and was treated with histone deacetylase inhibitors (HDACis) and gene expression was examined. We describe a patient-derived HAA1 cell line derived from the zona reticularis, the innermost zone of the adrenal cortex. The HAA1 cell line is unique in its ability to exit a latent state and respond with steroidogenic gene expression upon treatment with histone deacetylase inhibitors. The gene expression pattern of differentiated HAA1 cells partially recreates the roster of genes in the adrenal layer that they have been derived from. Gene ontology analysis of whole genome RNA-seq corroborated increased expression of steroidogenic genes upon HDAC inhibition. Surprisingly, HDACi treatment induced broad activation of the Tumor Necrosis Factor (TNF) alpha pathway. This novel cell line we developed will hopefully be instrumental in understanding the molecular and biochemical mechanisms controlling adrenocortical differentiation and steroidogenesis.

Primary Cultures and Cell Lines for In Vitro Modeling of the Human Adrenal Cortex.

The human adrenal cortex is a complex endocrine organ that produces mineralocorticoids, glucocorticoids and androgens. These steroids are produced in distinct cell types located within the glomerulosa, fasciculata and reticularis of the adrenal cortex. Abnormal adrenal steroidogenesis leads to a variety of diseases that can cause hypertension, metabolic syndrome, infertility and premature adrenarche. The adrenal cortex can also develop steroid-producing adenomas and rarely adrenocortical carcinomas. In vitro cell culture models provide important tools to study molecular and cellular mechanisms controlling both the physiologic and pathologic conditions of the adrenal cortex. In addition, the presence of multiple steroid-metabolizing enzymes within adrenal cells makes it a model for defining possible endocrine disruptors that might block these enzymes. The regulation and dysregulation of human adrenal steroid production and cell division/tumor growth can be studied using freshly isolated cells but this requires access to human adrenal glands, which are not available to most investigators. Immortalized human adrenocortical cell lines have proven to be of considerable value in studying the molecular and biochemical mechanisms controlling adrenal steroidogenesis and tumorigenesis. Current human adrenal cell lines include the original NCI-H295 and its substrains: H295A, H295R, HAC13, HAC15, HAC50 and H295RA as well as the recently established MUC-1, CU-ACC1 and CU-ACC2. The current review will discuss the use of primary cultures of fetal and adult adrenal cells as well as adrenocortical cell lines as in vitro models for the study of human adrenal physiology and pathophysiology.

Seated saline infusion test in predicting subtype diagnosis of primary aldosteronism.

CONTEXT: Although saline infusion test is widely used as a confirmatory test for primary aldosteronism (PA), it is reportedly less sensitive in patients in whom aldosterone is responsive to the upright position by performing it in recumbent position. Based on a single-centre experience, seated saline infusion test (SSIT) has been reported to be highly sensitive and superior to recumbent testing in identifying both unilateral and bilateral forms of PA. However, due to limited participants number, the utility of SSIT needs to be validated in other series. OBJECTIVE: This study aimed to evaluate the accuracy of SSIT in determining the PA subtypes compared with adrenocorticotropic hormone stimulation test under dexamethasone suppression (Dex-AT). PATIENTS AND SETTING: Sixty-four patients with PA who underwent both SSIT and Dex-AT were included. Subtype diagnosis of PA was determined by adrenal venous sampling (AVS) (16 unilateral and 48 bilateral forms). MAIN OUTCOME MEASURE: Plasma aldosterone concentrations (PACs) were measured after SSIT and Dex-AT. RESULTS: The area under the receiver operating characteristic (ROC) curve for diagnosing unilateral PA was greater in SSIT than that in Dex-AT (0.907 vs. 0.755; P = .023). ROC curve analysis predicted optimal cut-off PACs of 13.1 ng/dL (sensitivity, 93.8%; specificity, 79.2%) for SSIT and 34.2 ng/dL (sensitivity, 75.0%; specificity, 68.8%) for Dex-AT. CONCLUSIONS: Seated saline infusion test has superior accuracy in subtype diagnosis of PA compared with Dex-AT. SSIT can be a sensitive test for determining patients who require AVS prior to surgery.

Age-Related Autonomous Aldosteronism.

BACKGROUND: Both aging and inappropriate secretion of aldosterone increase the risk for developing cardiovascular disease; however, the influence of aging on aldosterone secretion and physiology is not well understood. METHODS: The relationship between age and adrenal aldosterone synthase (CYP11B2) expression was evaluated in 127 normal adrenal glands from deceased kidney donors (age, 9 months to 68 years). Following immunohistochemistry, CYP11B2-expressing area and areas of abnormal foci of CYP11B2-expressing cells, called aldosterone-producing cell clusters, were analyzed. In a separate ancillary clinical study of 677 participants without primary aldosteronism, who were studied on both high and restricted sodium diets (age, 18-71 years), we used multivariable linear regression to assess the independent associations between age and renin-angiotensin-aldosterone system physiology. RESULTS: In adrenal tissue, the total CYP11B2-expressing area was negatively correlated with age (r=-0.431, P<0.0001), whereas the total aldosterone-producing cell cluster area was positively correlated with age (r=0.390, P<0.0001). The integrated ratio of aldosterone-producing cell cluster to CYP11B2-expressing area was most strongly and positively correlated with age (r=0.587, P<0.0001). When participants in the clinical study were maintained on a high sodium balance, renin activity progressively declined with older age, whereas serum and urinary aldosterone did not significantly decline. Correspondingly, the aldosterone-to-renin ratio was positively and independently associated with older age (adjusted ß=+5.54 ng/dL per ng/mL per hour per 10 years, P<0.001). In contrast, when participants were assessed under sodium-restricted conditions, physiological stimulation of aldosterone was blunted with older age (ß=-4.6 ng/dL per 10 years, P<0.0001). CONCLUSIONS: Aging is associated with a pattern of decreased normal zona glomerulosa CYP11B2 expression and increased aldosterone-producing cell cluster expression. This histopathologic finding parallels an age-related autonomous aldosteronism and abnormal aldosterone physiology that provides 1 potential explanation for age-related cardiovascular risk.

Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands.

Primary aldosteronism (PA) represents the most common cause of secondary hypertension, but little is known regarding its adrenal cellular origins. Recently, aldosterone-producing cell clusters (APCCs) with high expression of aldosterone synthase (CYP11B2) were found in both normal and PA adrenal tissue. PA-causing aldosterone-producing adenomas (APAs) harbor mutations in genes encoding ion channels/pumps that alter intracellular calcium homeostasis and cause renin-independent aldosterone production through increased CYP11B2 expression. Herein, we hypothesized that APCCs have APA-related aldosterone-stimulating somatic gene mutations. APCCs were studied in 42 normal adrenals from kidney donors. To clarify APCC molecular characteristics, we used microarrays to compare the APCC transcriptome with conventional adrenocortical zones [zona glomerulosa (ZG), zona fasciculata, and zona reticularis]. The APCC transcriptome was most similar to ZG but with an enhanced capacity to produce aldosterone. To determine if APCCs harbored APA-related mutations, we performed targeted next generation sequencing of DNA from 23 APCCs and adjacent normal adrenal tissue isolated from both formalin-fixed, paraffin-embedded, and frozen tissues. Known aldosterone driver mutations were identified in 8 of 23 (35%) APCCs, including mutations in calcium channel, voltage-dependent, L-type, α1D-subunit (CACNA1D; 6 of 23 APCCs) and ATPase, Na(+)/(K+) transporting, α1-polypeptide (ATP1A1; 2 of 23 APCCs), which were not observed in the adjacent normal adrenal tissue. Overall, we show three major findings: (i) APCCs are common in normal adrenals, (ii) APCCs harbor somatic mutations known to cause excess aldosterone production, and (iii) the mutation spectrum of aldosterone-driving mutations is different in APCCs from that seen in APA. These results provide molecular support for APCC as a precursor of PA.

Discordance between imaging and immunohistochemistry in unilateral primary aldosteronism.

OBJECTIVE: Correct subtyping of primary aldosteronism (PA) is essential for good surgical outcomes. Adrenal vein sampling (AVS) and/or computed tomography (CT) are used for PA subclassification. Clinical and/or biochemical improvement after surgery, however, is not always achieved in patients with presumed unilateral PA. We aimed to identify the pitfalls in PA subclassification leading to surgical treatment failures. PATIENTS AND DESIGN: We retrospectively studied 208 patients who underwent adrenal vein sampling (AVS) for PA subclassification in a tertiary referral centre, between January 2009 and August 2016. Simultaneous bilateral AVS was performed before and after cosyntropin administration. We implemented immunohistochemistry for aldosterone synthase (CYP11B2) and 17α-hydroxylase/17,20 lyase (CYP17A1) in adrenal glands resected from patients without improvement of PA after surgical treatment and from those with limitations in AVS interpretation. RESULTS: Of 55 patients who underwent adrenalectomy, three (5.5%) had no improvement of PA. All three patients underwent partial adrenalectomy to remove a CT-detected nodule present on the same side with AVS lateralization. Immunohistochemistry revealed a CYP11B2-negative nodule in both cases available. All patients who underwent total adrenalectomy based on AVS lateralization benefitted from surgery, including three patients with unilateral unsuccessful AVS and aldosterone suppression in the catheterized side vs inferior vena cava. CONCLUSIONS: Radiographically identified adrenal nodules are not always a source of PA, even when ipsilateral with AVS lateralization. These data caution against reliance on imaging findings, either alone or in conjunction with AVS, to guide surgery for PA.

A family of RTHß with p.R316C mutation presenting occasional syndrome of inappropriate secretion of TSH.

The syndrome of inappropriate secretion of thyrotropin (SITSH) is a hallmark of resistance to thyroid hormone (RTH) due to mutations in the ß isoform of the thyroid hormone receptor (TRß). Here, we report on a family of RTH due to a TRß mutation (RTHß) and presenting occasional SITSH. The proband was a 16 year-old girl with a goiter, detected at a school physical examination. She was initially diagnosed as having euthyroid Hashimoto thyroiditis because her thyroid function was normal with a positive anti-thyroglobulin antibody. Follow-up examinations resulted in mild SITSH on some occasions and euthyroid on the other occasions. A magnetic resonance imaging (MRI) revealed a normal pituitary gland. Because her mother also had mild SITSH, genetic analysis was performed and revealed a heterozygous point mutation in TRß (p.R316C). Previously, the p.R316C had only been found in severe RTH cases with homozygous mutations or with an ectopic thyroid. Her mother with a heterozygous mutation showed variable RTH phenotype on T3 suppression testing. In conclusion, the prevalence of RTHß might be underestimated and occasional SITSH could also suggest RTHß. TRß gene mutation is not always correlated with the RTH phenotype.

Chronic kidney disease score for predicting postoperative masked renal insufficiency in patients with primary aldosteronism.

CONTEXT: Chronic kidney disease (CKD) is sometimes unmasked after unilateral adrenalectomy in patients with primary aldosteronism (PA) without expectation. OBJECTIVE: Our study aim was to elucidate factors responsible for developing postoperative CKD and to provide a simple scoring system to predict postoperative CKD in PA. DESIGN AND PATIENTS: Forty-five patients with PA treated with unilateral adrenalectomy and followed for at least 1 month postsurgery were studied. Thirty-one patients with non-PA adrenal disease who underwent unilateral adrenalectomy were also studied as control. Patients with pre-operative estimated glomerular filtration rate (eGFR) < 60 ml/min/1·73 m(2) were excluded from both groups. RESULTS: A statistically significant (P < 0·001) decrease in eGFR was observed in PA group within 1 month of surgery, then stabilized. Of the 45 patients with PA, 17 (37·8%) developed CKD after surgery. None of the non-PA group developed CKD after surgery. Of the pre-operative variables, logistic regression analysis showed that lower eGFR and higher aldosterone-to-renin ratios (ARR) were the independent predictors for postoperative CKD in PA. Optimal cut-off values of the two variables analysed with ROC curves were as follows: eGFR ≤ 76·9 ml/min/1·73 m(2) and ARR ≥ 305. Using these data, we created a CKD score as a tool for predicting postoperative CKD, with an AUC for the score of 0·8866. CONCLUSION: The pre-operative eGFR and ARR were the significant contributing factors for postoperative CKD in PA. By combining these independent factors, we created a CKD score which provides useful information before surgery about the risk for development of postoperative CKD.

Comparison of the utility of SARC-F, SARC-CalF, and calf circumference as screening tools for sarcopenia in patients with osteoporosis.

AIM: Patients with osteoporosis who also have sarcopenia are at a high risk for falls and fractures. Early detection of sarcopenia is crucial for these patients. This study aimed to compare the effectiveness of SARC-F, SARC-CalF, and calf circumference (CC) as screening tools for sarcopenia in patients with osteoporosis. METHODS: This cross-sectional study was retrospectively conducted on patients who attended the outpatient clinic for Osteoporosis and Sarcopenia at Kyoto Medical Center. Sarcopenia was determined based on low skeletal muscle mass and weak handgrip strength. Sensitivity and specificity analyses were conducted on SARC-F, SARC-CalF, and CC. The diagnostic utility of these three tools was compared using the receiver-operating characteristic (ROC) curves and the area under the ROC curves (AUC). RESULTS: A total of 225 patients (men/women: 33/192) with a median age of 69.0 years (interquartile range: 61.0‒75.0) were enrolled. The prevalence of sarcopenia was found to be 11.6%. CC had the highest sensitivity (80.8%), while SARC-F had the highest specificity (93.0%) for detecting sarcopenia. ROC analysis revealed that all three tools had significant potential for sarcopenia diagnosis, with SARC-CalF having the highest AUC compared to SARC-F and CC (0.753 vs. 0.619 and 0.700). A multivariate logistic regression, incorporating other confounders as explanatory variables, revealed that SARC-CalF was independently related to sarcopenia (odds ratio: 14.80, 95% confidence interval: 3.83-57.30, p < 0.001). CONCLUSION: In patients with osteoporosis, SARC-CalF is more effective in the early detection of sarcopenia than SARC-F and CC.

FSH-producing pituitary neuroendocrine tumor as a cause of ovarian hyperstimulation syndrome.

Summary: Functioning gonadotroph tumors are rare neoplasms that can cause ovarian hyperstimulation syndrome (OHSS) in women of reproductive age. Here, we present a case of a follicle-stimulating hormone (FSH)-producing pituitary neuroendocrine tumor (PitNET) with irregular menstrual cycles and OHSS in a Japanese woman. A 34-year-old woman with bilateral multi-cystic ovarian mass was referred to our hospital for ovarian surgery. The imaging feature of magnetic resonance imaging (MRI) of the ovary and elevated estradiol levels with normal FSH and low luteinizing hormone (LH) levels led us to suspect the presence of a functioning gonadotroph PitNET. MRI revealed a 19-mm pituitary tumor, and increased tracer uptake was observed in the pituitary lesion on 111In-pentetreotide scintigraphy. Transsphenoidal tumor resection resulted in the resolution of the ovarian enlargement, normalization of her menstrual cycles, and spontaneous pregnancy. Immunohistochemistry (IHC) of the resected tumor for pituitary transcription factors, including steroidogenesis factor 1 (SF1) and estrogen receptor alpha, demonstrated positive immunoreactivity, whereas IHC for pituitary-specific positive transcription factor 1 was negative, suggesting that the tumor belonged to the SF1 lineage of PitNETs (gonadotroph tumor). The tumor cells showed positive expression of FSHß, while LHß was mostly negative. Consistent with the high pituitary tumor uptake observed on 111In-pentetreotide scintigraphy, the pituitary tumor showed positive expression of somatostatin receptor 2A. Detailed clinical and histological evaluations will provide useful information to understand these rare functioning gonadotroph tumors better. Learning points: Functioning gonadotroph tumors are very rare neuroendocrine tumors of pituitary origin. Women of reproductive age presenting with bilateral multi-cystic ovarian enlargement, irregular menstrual cycles, and hyperestrogenemia under unsuppressed follicle-stimulating hormone (FSH) levels should be evaluated for FSH-producing tumor. Raising awareness of OHSS due to functioning gonadotroph tumors is crucial to prevent unnecessary ovarian surgery. Comprehensive histological analysis may provide useful information to better understand the characteristics of functioning gonadotroph tumors.

Double somatic mutations in CTNNB1 and GNA11 in an aldosterone-producing adenoma.

Double somatic mutations in CTNNB1 and GNA11/Q have recently been identified in a small subset of aldosterone-producing adenomas (APAs). As a possible pathogenesis of APA due to these mutations, an association with pregnancy, menopause, or puberty has been proposed. However, because of its rarity, characteristics of APA with these mutations have not been well characterized. A 46-year-old Japanese woman presented with hypertension and hypokalemia. She had two pregnancies in the past but had no history of pregnancy-induced hypertension. She had regular menstrual cycle at presentation and was diagnosed as having primary aldosteronism after endocrinologic examinations. Computed tomography revealed a 2 cm right adrenal mass. Adrenal venous sampling demonstrated excess aldosterone production from the right adrenal gland. She underwent right laparoscopic adrenalectomy. The resected right adrenal tumor was histologically diagnosed as adrenocortical adenoma and subsequent immunohistochemistry (IHC) revealed diffuse immunoreactivity of aldosterone synthase (CYP11B2) and visinin like 1, a marker of the zona glomerulosa (ZG), whereas 11ß-hydroxylase, a steroidogenic enzyme for cortisol biosynthesis, was mostly negative. CYP11B2 IHC-guided targeted next-generation sequencing identified somatic CTNNB1 (p.D32Y) and GNA11 (p.Q209H) mutations. Immunofluorescence staining of the tumor also revealed the presence of activated ß-catenin, consistent with features of the normal ZG. The expression patterns of steroidogenic enzymes and related proteins indicated ZG features of the tumor cells. PA was clinically and biochemically cured after surgery. In conclusion, our study indicated that CTNNB1 and GNA11-mutated APA has characteristics of the ZG. The disease could occur in adults with no clear association with pregnancy or menopause.

Bilateral Cortical-sparing Adrenalectomy for the Treatment of Bilateral Aldosterone-producing Adenomas.

Aldosterone-producing adenoma (APA) is 1 of the major subtypes of primary aldosteronism (PA). Although most APA occurs unilaterally, bilateral APAs have rarely been documented. Because of its rarity, optimal management of patients with bilateral APAs has not been established. Here, we report a case of bilateral APAs that was successfully treated with simultaneous bilateral cortical-sparing surgery. A 44-year-old Japanese woman was referred to us for the evaluation of PA. She had typical clinical characteristics of PA, including hypertension, hypokalemia, and high plasma aldosterone concentration with suppressed renin. She was diagnosed as having PA based on the results of confirmatory testing. Computed tomography revealed bilateral adrenal nodules with diameters of 17 and 10 mm on the right and left adrenal gland, respectively. Adrenal venous sampling indicated excess aldosterone production from bilateral adrenal lesions. She underwent simultaneous bilateral laparoscopic partial adrenalectomy that normalized her blood pressure and serum potassium levels. Aldosterone synthase immunohistochemistry on the resected adrenal tumor tissue confirmed the diagnosis of bilateral APAs. Long-term postsurgical follow-up data suggest cure of the disease without the need for glucocorticoid replacement therapy. Bilateral cortical-sparing adrenalectomy appears to be a viable treatment option at least for selected patients with bilateral APAs.

Comparison of the acceptability and safety of molnupiravir in COVID-19 patients aged over and under 80 years.

Background: Molnupiravir is being widely used as a treatment for coronavirus disease 2019 (COVID-19); however, its acceptability and safety in older patients aged ≥ 80 years in real-world clinical practice is not well understood. Methods: We conducted a single-centre retrospective study and assessed the outcome of patients with COVID-19 treated with molnupiravir according to the following criteria: (A) discontinuation rate of molnupiravir; (B) type, frequency, and severity of adverse events; (C) all-cause mortality within 30 days of the diagnosis of COVID-19. Results: Forty-seven patients (46.1%) were aged ≥ 80 years (older patients) and 55 (53.9%) were aged < 80 years (younger patients). There were no significant differences in coexisting diseases and history of vaccination for COVID-19 between older and younger patients. Older patients were significantly more likely to have moderate disease (moderate 1 and 2) according to the Japanese Ministry of Health, Labour and Welfare classification than younger patients. During treatment, 8.5% of older patients and 1.8% of younger patients stopped taking molnupiravir, but the difference was not significant. Adverse events were observed in 39/102 (38.2%) patients. The most common adverse events were diarrhoea (9.8%), exacerbation of coexisting diseases (6.9%), bone marrow suppression (6.9%), liver dysfunction (5.9%), and loss of appetite (4.9%). Most adverse events were minor, ranging from grades 1 to 3. The all-cause mortality rate was 10.8%, and no molnupiravir-related deaths were observed. Conclusions: Molnupiravir treatment is acceptable and safe in older patients with COVID-19 aged ≥ 80 years.

Somatic SLC30A1 mutations altering zinc transporter ZnT1 cause aldosterone-producing adenomas and primary aldosteronism.

Primary aldosteronism (PA) is the most common form of endocrine hypertension and is characterized by inappropriately elevated aldosterone production via a renin-independent mechanism. Driver somatic mutations for aldosterone excess have been found in approximately 90% of aldosterone-producing adenomas (APAs). Other causes of lateralized adrenal PA include aldosterone-producing nodules (APNs). Using next-generation sequencing, we identified recurrent in-frame deletions in SLC30A1 in four APAs and one APN (p.L51_A57del, n = 3; p.L49_L55del, n = 2). SLC30A1 encodes the ubiquitous zinc efflux transporter ZnT1 (zinc transporter 1). The identified SLC30A1 variants are situated close to the zinc-binding site (His43 and Asp47) in transmembrane domain II and probably cause abnormal ion transport. Cases of PA with SLC30A1 mutations showed male dominance and demonstrated increased aldosterone and 18-oxocortisol concentrations. Functional studies of the SLC30A151_57del variant in a doxycycline-inducible adrenal cell system revealed pathological Na+ influx. An aberrant Na+ current led to depolarization of the resting membrane potential and, thus, to the opening of voltage-gated calcium (Ca2+) channels. This resulted in an increase in cytosolic Ca2+ activity, which stimulated CYP11B2 mRNA expression and aldosterone production. Collectively, these data implicate zinc transporter alterations as a dominant driver of aldosterone excess in PA.

Two rare TSH receptor amino acid substitutions in toxic thyroid adenomas.

Toxic adenoma and toxic multinodular goiter (TMNG) are common causes of hyperthyroidism in iodine-deficient regions, but they are relatively rare in iodine-sufficient regions, including Japan. Constitutive activating mutations of the thyroid stimulating hormone receptor (TSHR) gene and adenylate cyclase-stimulating G α protein (GNAS) gene are frequent in these thyrotoxic disorders. Here we report two cases of rare TSHR gene mutations in Japanese thyrotoxicosis patients. In Case 1, we observed multiple toxic nodules with thyrotoxicosis, and in Case 2, we detected a solitary toxic nodule in an 8-year-old girl. In both cases, ultrasonography showed thyroid nodules and scintigraphy revealed increased uptake. Total thyroidectomy was performed for Case 1 and a hemi-thyroidectomy was performed for Case 2. Genetic analysis of the resected tissues revealed an I568F mutation in Case 1 and a S281I mutation in the TSHR gene in Case 2. The I568F mutation was located in the second extracellular loop, and the S281I mutation was located in the N-terminal extracellular domain of the TSH receptor. In Case 1, the mutation was restricted to the largest nodule, and was not detected in other functioning nodules or non-nodule thyroid tissue. Bi-allelic expression of the TSHR gene was confirmed by reverse transcription-polymerase chain reaction in both tumors. Both the I568F and S281I mutations were studied previously in vitro, and were revealed to cause basal activation of the protein kinase A pathway. Case 1 represents the second reported case of an I568F mutation and Case 2 represents the third reported case of an S281I mutation.

[Etiology and clinical guidelines for the diagnosis and treatment of pheochromocytoma in Japan].

Although pheochromocytoma is one curable cause of endocrine hypertension, approximately 10% of patients have malignant disease. Since the histopathologic diagnosis of malignancy at the time of first surgery is difficult and malignancy is confirmed only after the detection of metastasis, it is a representative intractable rare disease without effective treatment. A nationwide survey in Japan in 2009 found 2,600 cases of benign pheochromocytoma and 320 of malignant pheochromocytoma. There was no gender bias among patients, and the average age of onset was 40 to 45 years. Sixty-five percent were symptomatic including hypertension, but 35% were asymptomatic and found occasionally as incidentaloma Extraadrenal, bilateral, malignant, and familial cases each represented 10% of the total. A task force of the Ministry of Health, Labour and Welfare of Japan established the diagnostic criteria and clinical guidelines for pheochromocytoma/paraganglioma and malignant pheochromocytoma/paraganglioma. Typical cases of pheochromocytoma are readily diagnosed based on high catecholamine levels and imaging of tumor localization and can be cured by surgical resection of the tumor. In contrast, since no effective treatment for malignant pheochromocytoma has been established, a combination of various treatments including the administration of a-blockers, 131-MIBG irradiation, and cisplatin/vinblastine/dacarbazine chemotherapy, and radiation of bone metastases is recommended. Careful long-term follow-up is essential even in patients with benign pheochromocytoma.

Pathophysiology of bilateral hyperaldosteronism.

PURPOSE OF REVIEW: Renin-independent aldosterone production from one or both affected adrenal(s), a condition known as primary aldosteronism (PA), is a common cause of secondary hypertension. In this review, we aimed to summarize recent findings regarding pathophysiology of bilateral forms of PA, including sporadic bilateral hyperaldosteronism (BHA) and rare familial hyperaldosteronism. RECENT FINDINGS: The presence of subcapsular aldosterone synthase (CYP11B2)-expressing aldosterone-producing micronodules, also called aldosterone-producing cell clusters, appears to be a common histologic feature of adrenals with sporadic BHA. Aldosterone-producing micronodules frequently harbor aldosterone-driver somatic mutations. Other potential factors leading to sporadic BHA include rare disease-predisposing germline variants, circulating angiotensin II type 1 receptor autoantibodies, and paracrine activation of aldosterone production by adrenal mast cells. The application of whole exome sequencing has also identified new genes that cause inherited familial forms of PA. SUMMARY: Research over the past 10 years has significantly improved our understanding of the molecular pathogenesis of bilateral PA. Based on the improved understanding of BHA, future studies should have the ability to develop more personalized treatment options and advanced diagnostic tools for patients with PA.