Corrigendum to "Elevated amyloid beta peptides and total tau in cerebrospinal fluid in individuals with Creatine transporter deficiency".

[This corrects the article DOI: 10.1016/j.ymgmr.2023.101001.].

Elevated amyloid beta peptides and total tau in cerebrospinal fluid in individuals with Creatine transporter deficiency.

Background: Creatine transporter deficiency (CTD) is a rare X-linked disorder of creatine transport caused by pathogenic variants in SLC6A8 (Xq28). The disorder is marked by developmental delay, especially speech delay. The biomarkers Aß40, Aß42 and total tau are abnormal in Alzheimer disease (AD), a common neurodegenerative disorder pathologically characterized by Aß peptide containing amyloid plaques and tau neurofibrillary tangles. Although CTD results in neuronal energy deficiency, the pathological processes underlying the CTD phenotype are not fully characterized. Methods: Cerebral spinal fluid (CSF) was collected as an optional part of a natural history study of CTD. Aß40, Aß42 and total tau levels were quantified in CSF from individuals with CTD and from age-appropriate comparison samples. Neuro3-Plex enzyme-linked immunoassay was performed on a Quanterix SR-X instrument. The Vineland Adaptive Behavior Scale, 3rd Edition was used to determine an overall Adaptive Behavior Composite (ABC) standard score. Results: CSF from 12 individuals with CTD and 23 age appropriate non-CTD comparison samples were analyzed. We found that levels of total tau [t(32) = 4.05, p = 0.0003], Aß40 [t(31) = 6.11, p < 0.0001], and Aß42 [t(32) = 3.20, p = 0.003] were elevated in the participants with CTD relative to the comparison group. Additionally, except for one individual that we considered an outlier, all three biomarkers correlated inversely with the adaptive behavior score (total tau: ρ = -0.60 [-0.88, 0.005]; Aß40: ρ = -0.67 [-0.91, -0.12]; Aß42: ρ = -0.62 [-0.89, -0.02]). Conclusion: We describe here the novel finding of elevated protein biomarkers in the CSF of individuals with CTD. Aß40, Aß42 and total tau are markedly elevated in individuals with CTD compared to comparison samples, and increased levels of these biomarkers inversely correlated with ABC scores. We hypothesize that elevated CSF levels of Aß40 and Aß42 are due to cellular energy deficiency. Elevated CSF total tau levels may indicate ongoing neuronal damage. The observed inverse correlation of Vineland ABC scores with increased biomarker levels needs to be confirmed in a larger CTD cohort; however, our observation of increased Aß40, Aß42 and total tau levels in CSF from individuals with CTD may provide insight into pathological mechanisms contributing to the CTD phenotype and may prove useful as supportive data in future therapeutic trials.

Rare disease variant curation from literature: assessing gaps with creatine transport deficiency in focus.

BACKGROUND: Approximately 4-8% of the world suffers from a rare disease. Rare diseases are often difficult to diagnose, and many do not have approved therapies. Genetic sequencing has the potential to shorten the current diagnostic process, increase mechanistic understanding, and facilitate research on therapeutic approaches but is limited by the difficulty of novel variant pathogenicity interpretation and the communication of known causative variants. It is unknown how many published rare disease variants are currently accessible in the public domain. RESULTS: This study investigated the translation of knowledge of variants reported in published manuscripts to publicly accessible variant databases. Variants, symptoms, biochemical assay results, and protein function from literature on the SLC6A8 gene associated with X-linked Creatine Transporter Deficiency (CTD) were curated and reported as a highly annotated dataset of variants with clinical context and functional details. Variants were harmonized, their availability in existing variant databases was analyzed and pathogenicity assignments were compared with impact algorithm predictions. 24% of the pathogenic variants found in PubMed articles were not captured in any database used in this analysis while only 65% of the published variants received an accurate pathogenicity prediction from at least one impact prediction algorithm. CONCLUSIONS: Despite being published in the literature, pathogenicity data on patient variants may remain inaccessible for genetic diagnosis, therapeutic target identification, mechanistic understanding, or hypothesis generation. Clinical and functional details presented in the literature are important to make pathogenicity assessments. Impact predictions remain imperfect but are improving, especially for single nucleotide exonic variants, however such predictions are less accurate or unavailable for intronic and multi-nucleotide variants. Developing text mining workflows that use natural language processing for identifying diseases, genes and variants, along with impact prediction algorithms and integrating with details on clinical phenotypes and functional assessments might be a promising approach to scale literature mining of variants and assigning correct pathogenicity. The curated variants list created by this effort includes context details to improve any such efforts on variant curation for rare diseases.

Ascending Aorta 4D Time to Peak Distention Sexual Dimorphism and Association with Coronary Plaque Burden Severity in Women.

Coronary artery disease (CAD) risk and plaque scores are often subjective and biased, particularly in mid-age asymptomatic women, whose CAD risk assessment has been historically underestimated. In this study, a new automatic ascending aorta time-to-peak-distention (TPD) analysis was developed for fast screening and as an independent surrogate for subclinical atherosclerosis in asymptomatic women. CCTA was obtained in 50 asymptomatic adults. Plaque burden segment involvement score (SIS) and automatic TPD were obtained from all subjects. Logistic regression analyses were performed to investigate the association between CAD risk scores and TPD with severe coronary plaque burden (SIS>5). TPD, individually, was found to be a significant predictor of SIS>5. Additionally, sex was a significant effect modifier of TPD, with a stronger statistically significant association with women. Four-dimensional aortic time-to-peak distention could supplement conventional CCTA analysis and offer a quick objective screening tool for plaque burden severity and CAD risk stratification, especially in women.

Characterizing Hypertension Specialist Care in Canada: A National Survey.

Background: The hypertension specialist often receives referrals of patients with young-onset, severe, difficult-to-control hypertension, patients with hypertensive emergencies, and patients with secondary causes of hypertension. Specialist hypertension care compliments primary care for these complex patients and contributes to an overall hypertension control strategy. The objective of this study was to characterize hypertension centres and the practice patterns of Canadian hypertension specialists. Methods: Adult hypertension specialists across Canada were surveyed to describe hypertension centres and specialist practice in Canada, including the following: the patient population managed by hypertension specialists; details on how care is provided; practice pattern variations; and differences in access to specialized hypertension resources across the country. Results: The survey response rate was 73.5% from 25 hypertension centres. Most respondents were nephrologists and general internal medicine specialists. Hypertension centres saw between 50 and 2500 patients yearly. A mean of 17% (± 15%) of patients were referred from the emergency department and a mean of 52% (± 24%) were referred from primary care. Most centres had access to specialized testing (adrenal vein sampling, level 1 sleep studies, autonomic testing) and advanced therapies for resistant hypertension (renal denervation). Considerable heterogeneity was present in the target blood pressure in young people with low cardiovascular risk and in the diagnostic algorithms for investigating secondary causes of hypertension. Conclusions: These results summarize the current state of hypertension specialist care and highlight opportunities for further collaboration among hypertension specialists, including standardization of the approach to specialist care for patients with hypertension.

Contexte: Le spécialiste de l'hypertension reçoit souvent des patients orientés pour une hypertension sévère, d'apparition précoce et difficile à maîtriser, pour une urgence hypertensive ou pour des causes secondaires de l'hypertension. Les soins spécialisés de l'hypertension complètent les soins primaires pour ces cas complexes et font partie d'une stratégie globale de maîtrise de l'hypertension. Cette étude avait pour objectif de caractériser les centres de traitement de l'hypertension et les habitudes de pratique des spécialistes canadiens qui traitent l'hypertension. Méthodologie: Un sondage a été mené auprès de spécialistes de l'hypertension adulte de l'ensemble du Canada afin de décrire les centres de traitement de l'hypertension et la pratique des spécialistes au Canada, notamment les éléments suivants : la population de patients prise en charge par des spécialistes de l'hypertension, les renseignements sur la façon dont les soins sont prodigués, les variations dans les habitudes de pratique ainsi que les différences relatives à l'accès aux ressources spécialisées en hypertension à l'échelle du pays. Résultats: Le taux de réponse au sondage a été de 73,5 % dans 25 centres de l'hypertension. La plupart des répondants étaient des néphrologues et des spécialistes en médecine interne générale. Les centres de l'hypertension recevaient entre 50 et 2500 patients par année. En moyenne, 17 % (± 15 %) des patients provenaient du service des urgences et 52 % (± 24 %) provenaient d'une unité de soins primaires. La plupart des centres avaient accès à des tests spécialisés (prélèvements veineux surrénaliens, études du sommeil de niveau 1, tests autonomes) et à des traitements avancés pour l'hypertension résistante (dénervation rénale). Une hétérogénéité considérable a été constatée en ce qui concerne la pression artérielle cible chez les jeunes présentant un faible risque cardiovasculaire et les algorithmes diagnostiques pour étudier les causes secondaires de l'hypertension. Conclusions: Ces résultats résument la situation actuelle des soins spécialisés de l'hypertension et font ressortir des occasions d'accroître la collaboration entre les spécialistes de l'hypertension, notamment en ce qui concerne une normalisation de l'approche des soins spécialisés pour les patients hypertendus.

Update on the Genetics of Primary Aldosteronism and Aldosterone-Producing Adenomas.

PURPOSE OF THE REVIEW: Primary aldosteronism (PA) is the leading cause of secondary hypertension, accounting for over 10% of patients with high blood pressure. It is characterized by autonomous production of aldosterone from the adrenal glands leading to low-renin levels. The two most common forms arise from bilateral adrenocortical hyperplasia (BAH) and aldosterone-producing adenoma (APA). We discuss recent discoveries in the genetics of PA. RECENT FINDINGS: Most APAs harbor variants in the KCNJ5, CACNA1D, ATP1A1, ATP2B3, and CTNNB1 genes. With the exception of ß-catenin (CTNNB1), all other causative genes encode ion channels; pathogenic variants found in PA lead to altered ion transportation, cell membrane depolarization, and consequently aldosterone overproduction. Some of these genes are found mutated in the germline state (CYP11B2, CLCN2, KCNJ5, CACNA1H, and CACNA1D), leading then to familial hyperaldosteronism, and often BAH rather than single APAs. Several genetic defects in the germline or somatic state have been identified in PA. Understanding how these molecular abnormalities lead to excess aldosterone contributes significantly to the elucidation of the pathophysiology of low-renin hypertension. It may also lead to new and more effective therapies for this disease acting at the molecular level.

USP13 genetics and expression in a family with thyroid cancer.

PURPOSE: Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma and its incidence has greatly increased in the last 30 years. Ubiquitin-specific protease 13 (USP13) is a class of deubiquitinating enzymes (DUBs) and plays an important role in cellular functions such as cell cycle regulation, DNA damage repair, and different cell signaling pathways. Studies regarding the role of USP13 in cancer development and progression are divergent and there are no previous data regarding the role of USP13 gene in PTCs. In this study, we investigated the genetic cause of PTC diagnosed in multiple members of a Brazilian family. METHODS: Whole exome sequencing (WES) was performed to identify the genetic cause of PTC. Cycloheximide chase assay and clonogenic assay were performed to study USP13 stability and function in vitro. RESULTS: WES analysis identified a heterozygous missense variant c.1483G > A (p.V495M) in the USP13 gene that fully segregates with the disease. In silico modeling suggests that this variant may cause protein structural perturbations. USP13 overexpression increased the potential of a single cell to form colonies. The USP13 c.1483G > A variant enhanced the effects seen in USP13 overexpression and preserved protein stability for longer hours compared to the non-mutated USP13 protein. CONCLUSION: Our study suggests that USP13 overexpression may play a role in tumorigenesis of PTCs; and that the USP13 p.V495M (c.1483G > A) variant enhances USP13 estability.

Neurofibromatosis Type 1 Has a Wide Spectrum of Growth Hormone Excess.

Overgrowth due to growth hormone (GH) excess affects approximately 10% of patients with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG). Our aim is to describe the clinical, biochemical, pathological, and genetic features of GH excess in a retrospective case series of 10 children and adults with NF1 referred to a tertiary care clinical research center. Six children (median age = 4 years, range of 3−5 years), one 14-year-old adolescent, and three adults (median age = 42 years, range of 29−52 years) were diagnosed with NF1 and GH excess. GH excess was confirmed by the failure to suppress GH (<1 ng/mL) on oral glucose tolerance test (OGTT, n = 9) and frequent overnight sampling of GH levels (n = 6). Genetic testing was ascertained through targeted or whole-exome sequencing (n = 9). Five patients (all children) had an OPG without any pituitary abnormality, three patients (one adolescent and two adults) had a pituitary lesion (two tumors, one suggestive hyperplasia) without an OPG, and two patients (one child and one adult) had a pituitary lesion (a pituitary tumor and suggestive hyperplasia, respectively) with a concomitant OPG. The serial overnight sampling of GH levels in six patients revealed abnormal overnight GH profiling. Two adult patients had a voluminous pituitary gland on pituitary imaging. One pituitary tumor from an adolescent patient who harbored a germline heterozygous p.Gln514Pro NF1 variant stained positive for GH and prolactin. One child who harbored a heterozygous truncating variant in exon 46 of NF1 had an OPG that, when compared to normal optic nerves, stained strongly for GPR101, an orphan G protein-coupled receptor causing GH excess in X-linked acrogigantism. We describe a series of patients with GH excess and NF1. Our findings show the variability in patterns of serial overnight GH secretion, somatotroph tumor or hyperplasia in some cases of NF1 and GH excess. Further studies are required to ascertain the link between NF1, GH excess and GPR101, which may aid in the characterization of the molecular underpinning of GH excess in NF1.

Scoping review of COVID-19-related systematic reviews and meta-analyses: can we really have confidence in their results?

AIM: The aim of this study was to systematically appraise the quality of a sample of COVID-19-related systematic reviews (SRs) and discuss internal validity threats affecting the COVID-19 body of evidence. DESIGN: We conducted a scoping review of the literature. SRs with or without meta-analysis (MA) that evaluated clinical data, outcomes or treatments for patients with COVID-19 were included. MAIN OUTCOME MEASURES: We extracted quality characteristics guided by A Measurement Tool to Assess Systematic Reviews-2 to calculate a qualitative score. Complementary evaluation of the most prominent published limitations affecting the COVID-19 body of evidence was performed. RESULTS: A total of 63 SRs were included. The majority were judged as a critically low methodological quality. Most of the studies were not guided by a pre-established protocol (39, 62%). More than half (39, 62%) failed to address risk of bias when interpreting their results. A comprehensive literature search strategy was reported in most SRs (54, 86%). Appropriate use of statistical methods was evident in nearly all SRs with MAs (39, 95%). Only 16 (33%) studies recognised heterogeneity in the definition of severe COVID-19 as a limitation of the study, and 15 (24%) recognised repeated patient populations as a limitation. CONCLUSION: The methodological and reporting quality of current COVID-19 SR is far from optimal. In addition, most of the current SRs fail to address relevant threats to their internal validity, including repeated patients and heterogeneity in the definition of severe COVID-19. Adherence to proper study design and peer-review practices must remain to mitigate current limitations.

Hypertension and COVID-19: Updates from the era of vaccines and variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen responsible for coronavirus disease 2019 (COVID-19) has been a major cause of morbidity and mortality globally. Older age, and the presence of certain components of metabolic syndrome, including hypertension have been associated with increased risk for severe disease and death in COVID-19 patients. The role of antihypertensive agents in the pathogenesis of COVID-19 has been extensively studied since the onset of the pandemic. This review discusses the potential pathophysiologic interactions between hypertension and COVID-19 and provides an up-to-date information on the implications of newly emerging SARS-CoV-2 variants, and vaccines on patients with hypertension.

Survivorship Issues in Adult Patients With Histiocytic Neoplasms.

Adult-onset histiocytoses (AOH), primarily Rosai-Dorfman disease (RDD), Erdheim-Chester Disease (ECD), and adult Langerhans cell histiocytosis (ALCH), are a group of related histiocytic neoplastic disorders featuring multisystemic manifestations. The disorders are largely incurable, and are essentially chronic neoplastic diseases with a variable prognosis. Prompt diagnosis and treatment is important to prevent debilitating and even life-threatening complications. Survivorship issues abound in AOH, due to their multisystemic manifestations and the sometimes recalcitrant chronic inflammation, which can lead to other debilitating complications such as fatigue, weakness, and pain. Because these disorders are rare, few healthcare professionals are proficient in their management; therefore the aim of these guidelines is to offer guidance on how to manage patients, and how to create survivorship care plans through the efforts of an interdisciplinary team.

Homozygous SHBG Variant (rs6258) Linked to Gonadotropin-Independent Precocious Puberty in a Young Girl.

Sex hormone-binding globulin (SHBG) in the blood is a major determinant of bioactivity for key sex steroids such as testosterone and estradiol. Low serum levels of SHBG have been associated with obesity, polycystic ovaries, and metabolic syndrome, and other states associated with hyperandrogenemia. A 9-year, 6-month-old girl presented with a history of peripheral precocious puberty and aggressive behavior. The patient's SHBG level was remarkably low for her age, at less than 5 nmol/L (reference range for a girl with a bone age of 10 years, 73 nmol/L [SEM = 10]) [1]. On genetic and protein analysis, the patient was found to have a homozygous missense potentially pathogenic variant in the SHBG gene (c.554C>T, p.P185L); her parents were asymptomatic heterozygote carriers. Laboratory investigations supported the possible involvement of this genetic alteration in the patient's phenotype. Various analyses of this variant support its pathogenicity, although the exact mechanism remains unclear. In conclusion, we present a genetic SHBG variant in the homozygote state that may have been associated with gonadotropin-independent precocious puberty in a young girl.

Pituitary Imaging Abnormalities and Related Endocrine Disorders in Erdheim-Chester Disease.

PURPOSE: We examined abnormal pituitary imaging (API) and associated endocrine dysfunction in subjects with ECD. METHODS: A cross-sectional descriptive examination of a natural history cohort study diagnosed with ECD was conducted at a clinical research center. Subjects underwent baseline endocrine tests of anterior and posterior pituitary function and dedicated pituitary gland MRI scans. We determined the frequency of various pituitary imaging abnormalities in ECD and assessed its relationships with age, sex, body mass index (BMI), BRAF V600E status, high sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), pituitary hormone deficits and number, diabetes insipidus (DI), and panhypopituitarism. RESULTS: Our cohort included 61 subjects with ECD [age (SD): 54.3 (10.9) y, 46 males/15 females]. API was present in 47.5% (29/61) of ECD subjects. Loss of the posterior pituitary bright spot (36.1%) followed by thickened pituitary stalk (24.6%), abnormal enhancement (18.0%), and pituitary atrophy (14.8%) were the most common abnormalities. DI and panhypopituitarism were more frequent in subjects with API without differences in age, sex distribution, hsCRP, ESR, and BRAF V600E status compared to normal pituitary imaging. CONCLUSIONS: We noted a high burden of API and endocrinopathies in ECD. API was highly associated with the presence of panhypopituitarism and DI. Therefore, a thorough assessment of hypothalamic-pituitary integrity should be considered in subjects with ECD.

X-linked creatine transporter deficiency results in prolonged QTc and increased sudden death risk in humans and disease model.

PURPOSE: Creatine transporter deficiency (CTD) is a rare X-linked disorder of creatine transport caused by pathogenic variants in SLC6A8 (Xq28). CTD features include developmental delay, seizures, and autism spectrum disorder. This study was designed to investigate CTD cardiac phenotype and sudden death risk. METHODS: We performed a cross-sectional analysis of CTD males between 2017 and 2020. Subjects underwent evaluation with electrocardiogram (ECG), echocardiography, and ambulatory ECG with comparable analysis in creatine transporter deficient mice (Slc6a8-/y) using ECG, echocardiography, exercise testing, and indirect calorimetry. RESULTS: Eighteen subjects with CTD (18 males, age 7.4 [3.8] years) were evaluated: seven subjects (39%) had QTc ≥ 470 milliseconds: 510.3 ± 29.0 vs. 448.3 ± 15.9, P < 0.0001. The QTc ≥ 470 milliseconds cohort had increased left ventricular internal dimension (diastole) ([LVIDd] Z-score: 0.22 ± 0.74, n = 7 vs. -0.93 ± 1.0, n = 11, P = 0.0059), and diminished left ventricular posterior wall dimension (diastole) ([LVPWDd, in mm]: 5.0 ± 0.6, n = 7 vs. 5.7 ± 0.8, n = 11, P = 0.0183), when compared to subjects with normal or borderline QTc prolongation. Similar ECG and echocardiographic abnormalities were seen in Slc6a8-/y mice. Additionally, Slc6a8-/y mice had diminished survival (65%). CONCLUSION: Prolonged QTc and abnormal echocardiographic parameters consistent with developing cardiomyopathy are seen in some male subjects with CTD. Slc6a8-/y mice recapitulated these cardiac abnormalities. Male CTD subjects may be at increased risk for cardiac dysfunction and sudden death.

Contralateral Suppression Index Does Not Predict Clinical Cure in Patients Undergoing Surgery for Primary Aldosteronism.

BACKGROUND: Adrenal venous sampling (AVS) is recommended before adrenalectomy for patients with primary aldosteronism (PA) over 35 years old. The literature examining contralateral suppression (CoS) on AVS in predicting surgical outcomes is conflicting. We examined the presence of CoS in patients who underwent adrenalectomy while adjusting for clinical and biochemical factors associated with a clinical cure of hypertension (ccHTN). METHODS: We performed a retrospective review of patients with successful AVS who underwent unilateral adrenalectomy for PA at a quaternary referral center. Patients were excluded if they had overt cortisol co-secretion, or inadequate follow-up. We first evaluated the aldosterone resolution score (ARS) in predicting ccHTN in our cohort. Next, the receiver-operator characteristic analysis (ROC) was used to determine the optimal contralateral suppression index (CSI) cutoff to define CoS. We performed univariable and multivariable analyses of factors associated with ccHTN. The primary outcome was ccHTN defined as blood pressure less than 140/90 mmHg, and off blood pressure medications. RESULTS: Of the 102 patients on bivariable analysis, age, sex, duration of HTN, number of medications, preoperative systolic blood pressure, and creatinine level were associated with ccHTN. ROC analysis of ARS had an AUC of 0.850 (p < 0.001). On multivariable analysis, only ARS remained associated with ccHTN (OR 3.40, 95% CI 1.20-9.61, p = 0.021). CSI was not significantly associated with ccHTN on ROC, bivariable, or multivariable analyses. CONCLUSION: The presence of CoS was not useful in predicting ccHTN following unilateral adrenalectomy for PA in our cohort. After adjusting for clinical and biochemical factors, ARS remains a useful predictor for ccHTN.

A case of Carney triad complicated by renal cell carcinoma and a germline SDHA pathogenic variant.

SUMMARY: Succinate dehydrogenase deficiency has been associated with several neoplasias, including renal cell carcinoma (RCC) and those associated with hereditary paraganglioma (PGL)/ pheochromocytoma (PHEO) syndromes, Carney dyad, and Carney triad. Carney triad is a rare multitumoral syndrome characterized by co-existing PGL, gastrointestinal stromal tumor (GIST), and pulmonary chondroma (CHO). We report a case of a 57-year-old male who presented with para-aortic and gastroesophogeal masses, and a right renal superior pole lesion, which were classified as multiple PGLs, a GIST, and a clear cell renal carcinoma, respectively, on pathology following surgical resection. Additionally, a CHO was diagnosed radiologically, although no biopsy was performed. A diagnosis of Carney triad was made. SDHB immunohistochemical staining was negative for the PGL and the GIST, indicating SDH-deficiency. Interestingly, the renal cell carcinoma (RCC) stained positive for both SDHB and SDHA. Subsequent genetic screening of SDH subunit genes revealed a germline inactivating heterozygous SDHA pathogenic variant (c.91 C>T, p.R31X). Loss of heterozygosity was not detected at the tumor level for the RCC, which likely indicated the SDHA variant would not be causative of the RCC, but could still predispose to the development of neoplasias. To the knowledge of the authors this is the first reported case of an SDHA pathogenic variant in a patient with Carney triad complicated by RCC. LEARNING POINTS: The succinate dehydrogenase enzyme is encoded by four subunit genes (SDHA, SDHB, SDHC, and SDHD; collectively referred to as SDHx), which have been implicated in several neoplasias and are classified as tumor suppressor genes. Carney triad is a rare multiple-neoplasia syndrome presenting as an association of PGLs, GISTs, and CHOs. Carney triad is most commonly associated with hypermethylation of SDHC as demonstrated in tumor tissue, but approximately 10% of cases are due to pathogenic SDHx variants. Although SDHB pathogenic variants are most commonly reported in SDH-deficient renal cell carcinoma, SDHA disease-causing variants have been reported in rare cases.

Molecular Genetic and Genomic Alterations in Cushing's Syndrome and Primary Aldosteronism.

The genetic alterations that cause the development of glucocorticoid and/or mineralocorticoid producing benign adrenocortical tumors and hyperplasias have largely been elucidated over the past two decades through advances in genomics. In benign aldosterone-producing adrenocortical tumors and hyperplasias, alteration of intracellular calcium signaling has been found to be significant in aldosterone hypersecretion, with causative defects including those in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2. In benign cortisol-producing adrenocortical tumors and hyperplasias abnormal cyclic adenosine monophosphate-protein kinase A signaling has been found to play a central role in tumorigenesis, with pathogenic variants in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B being implicated. The role of this signaling pathway in the development of Cushing's syndrome and adrenocortical tumors was initially discovered through the study of the underlying genetic defects causing the rare multiple endocrine neoplasia syndromes McCune-Albright syndrome and Carney complex with subsequent identification of defects in genes affecting the cyclic adenosine monophosphate-protein kinase A pathway in sporadic tumors. Additionally, germline pathogenic variants in ARMC5, a putative tumor suppressor, were found to be a cause of cortisol-producing primary bilateral macronodular adrenal hyperplasia. This review describes the genetic causes of benign cortisol- and aldosterone-producing adrenocortical tumors.

First Somatic PRKAR1A Defect Associated With Mosaicism for Another PRKAR1A Mutation in a Patient With Cushing Syndrome.

CONTEXT: Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent Cushing syndrome (CS) associated mostly with Carney complex (CNC), a rare autosomal dominant multiple neoplasia syndrome. More than two-thirds of familial cases and approximately one-third of sporadic cases of CNC harbor germline inactivating PRKAR1A defects. Increasingly sensitive technologies for the detection of genetic defects such as next-generation sequencing (NGS) have further highlighted the importance of mosaicism in human disease. CASE DESCRIPTION: A 33-year-old woman was diagnosed with ACTH-independent CS with abdominal computed tomography showing bilateral micronodular adrenal hyperplasia with a left adrenal adenoma. She underwent left adrenalectomy with pathology demonstrating PPNAD with a 1.5-cm pigmented adenoma. DNA analysis by Sanger sequencing revealed 2 different PRKAR1A variants in the adenoma that were absent from DNA extracted from blood and saliva: c.682C > T and c.974-2A > G. "Deep" NGS revealed that 0.31% of DNA copies extracted from blood and saliva did in fact carry the c.682C > T variant, suggesting low-level mosaicism for this defect. CONCLUSIONS: We present a case of PPNAD due to low-level mosaicism for a PRKAR1A defect which led to the formation of an adenoma due to a second, adrenal-specific, somatic PRKAR1A mutation. The identification of mosaicism for PRKAR1A, depending on the number and distribution of cells affected has implications for genetic counseling and tumor surveillance. This is the first recorded case of a patient with PRKAR1A mosaicism, PPNAD, and an adenoma forming due to complete inactivation of PRKAR1A in adrenal tissue from a second, somatic-only, PRKAR1A coding sequence mutation.