A unique haplotype of RCCX copy number variation: from the clinics of congenital adrenal hyperplasia to evolutionary genetics.

There is a difficulty in the molecular diagnosis of congenital adrenal hyperplasia (CAH) due to the c.955C>T (p.(Q319*), formerly Q318X, rs7755898) variant of the CYP21A2 gene. Therefore, a systematic assessment of the genetic and evolutionary relationships between c.955C>T, CYP21A2 haplotypes and the RCCX copy number variation (CNV) structures, which harbor CYP21A2, was performed. In total, 389 unrelated Hungarian individuals with European ancestry (164 healthy subjects, 125 patients with non-functioning adrenal incidentaloma and 100 patients with classical CAH) as well as 34 adrenocortical tumor specimens were studied using a set of experimental and bioinformatic methods. A unique, moderately frequent (2%) haplotypic RCCX CNV structure with three repeated segments, abbreviated to LBSASB, harboring a CYP21A2 with a c.955C>T variant in the 3'-segment, and a second CYP21A2 with a specific c.*12C>T (rs150697472) variant in the middle segment occurred in all c.955C>T carriers with normal steroid levels. The second CYP21A2 was free of CAH-causing mutations and produced mRNA in the adrenal gland, confirming its functionality and ability to rescue the carriers from CAH. Neither LBSASB nor c.*12C>T occurred in classical CAH patients. However, CAH-causing CYP21A2 haplotypes with c.955C>T could be derived from the 3'-segment of LBSASB after the loss of functional CYP21A2 from the middle segment. The c.*12C>T indicated a functional CYP21A2 and could distinguish between non-pathogenic and pathogenic genomic contexts of the c.955C>T variant in the studied European population. Therefore, c.*12C>T may be suitable as a marker to avoid this genetic confound and improve the diagnosis of CAH.

[Analysis of laboratory data of 155 patients with pheochromocytoma-paraganglioma syndrome diagnosed during the past 20 years]. / A laboratóriumi diagnosztika eredményei az elmúlt 20 évben kórismézett 155 phaeochromocytoma/paraganglioma szindrómás beteg adatainak elemzése alapján.

INTRODUCTION: Laboratory diagnosis of pheochromocytoma-paraganglioma syndrome has been markedly improved during the past two decades. AIM: Retrospective assessment of diagnostic utility of urinary catecholamines and their metabolites as well as serum chromogranin A in 155 patients diagnosed at the 2nd Department of Medicine, Semmelweis University. METHOD: Urinary catecholamines and metabolites were measured using high-performance liquid chromatography with electrochemical detection in 155 patients with pheochromocytoma-paraganglioma (of whom 28.4% had hereditary background) and in 170 non-pheochromocytoma patients used as controls. Serum chromogranin A was measured by immunoradiometry. RESULTS: Sensitivity (93.2%) and specificity (87.0%) of urinary fractionated metanephrines were higher than those of urinary catecholamines (90.9% vs. 85.7%, respectively) and serum chromogranin A (88.7% and 77.5%, respectively). Urinary normetanephrine and serum chromogranin A correlated positively with tumor size (r = 0.552, p<0.0001 and r = 0.618, p<0.0001, respectively). CONCLUSIONS: These data confirm the diagnostic utility of urinary catecholamines and their metabolites. Urinary normetanephrine and serum chromogranin A may help to estimate tumour mass and probably tumour progression.

Common genetic variants of the human steroid 21-hydroxylase gene (CYP21A2) are related to differences in circulating hormone levels.

PURPOSE: Systematic evaluation of the potential relationship between the common genetic variants of CYP21A2 and hormone levels. METHODS: The relationships of CYP21A2 intron 2 polymorphisms and haplotypes with diverse baseline and stimulated blood hormone levels were studied in 106 subjects with non-functioning adrenal incidentaloma (NFAI). The rationale for using NFAI subjects is dual: i) their baseline hormone profiles do not differ from those of healthy subjects and ii) hormone levels after stimulation tests are available. RESULTS: The carriers (N = 27) of a well-defined CYP21A2 haplotype cluster (c5) had significantly elevated levels of cortisol (p = 0.0110), and 17-hydroxyprogesterone (p = 0.0001) after ACTH stimulation, and 11-deoxycortisol after metyrapone administration (p = 0.0017), but the hormone values were in normal ranges. In addition, the carriers (N = 33) of the C allele of the rs6462 polymorphism had a higher baseline aldosterone level (p = 0.0006). The prevalence of these genetic variants of CYP21A2 did not differ between NFAI and healthy subjects. CONCLUSIONS: The common CYP21A2 variants presumably exert the same effect on hormone levels in the healthy and disease-affected populations. Therefore, they may contribute to complex diseases such as some cardiovascular diseases, and may influence the genotype-phenotype correlation in patients with congenital adrenal hyperplasia (CAH) including the individual need for hormone substitution.

Diagnostic performance of salivary cortisol and serum osteocalcin measurements in patients with overt and subclinical Cushing's syndrome.

OBJECTIVE: The cut-off value for salivary cortisol measurement for the diagnosis of Cushing's syndrome (CS) may depend both on the severity of the disease and the composition of control group. Therefore, we examined the utility of midnight salivary cortisol measurements in patients who were evaluated for signs and symptoms of CS or because they had adrenal incidentalomas. Because serum osteocalcin (OC) is considered as a sensitive marker of hypercortisolism, we also investigated whether OC could have a role in the diagnosis of CS. PATIENTS AND METHODS: Each of the 151 patients was included into one of the following groups: (A) overt CS (n=23), (B) subclinical CS (n=18), (C) inactive adrenal adenomas (n=40), (D) patients without HPA disturbances (n=70). Patients (C+D) were used as controls. Serum, salivary and urinary cortisol, and OC were measured by electrochemiluminescence immunoassay. RESULTS: Group A had suppressed OC as compared to both group B and group (C+D). Serum and salivary cortisol concentrations showed strong negative correlations with OC in patients with overt CS. The areas under the curves of salivary and serum cortisol at 24:00 h (0.9790 and 0.9940, respectively) serum cortisol after low dose dexamethasone test (0.9930) and OC (0.9220) obtained from ROC analysis for the diagnosis of overt CS were not statistically different. CONCLUSION: This study confirms the usefulness of midnight salivary cortisol measurements in the diagnosis of overt CS in the everyday endocrinological praxis. Our results suggest that OC may have a role in the diagnosis of overt CS.

Cutoff values of midnight salivary cortisol for the diagnosis of overt hypercortisolism are highly influenced by methods.

BACKGROUND: Midnight salivary cortisol (MSC) concentration has been considered as a sensitive marker of overt hypercortisolism. Because no studies on commercially available automated, non-isotopic MSC assays have been reported, we determined and compared the diagnostic performance of an automated electrochemiluminescent immunoassay (ECLIA, Elecsys E170) and an in-house radioimmunoassay (RIA) for MSC measurement. METHODS: The study involved 126 consecutive patients referred for evaluation because of symptoms of Cushing's syndrome, obesity, or the presence of incidentally discovered adrenal adenoma. Using detailed clinical, hormonal and radiological evaluation overt endogenous hypercortisolism was confirmed in 9 patients and was excluded in 117 patients. RESULTS: ROC analysis indicated that the best performance of MSC was obtained at cutoff value of 0.35 microg/dl using ECLIA (sensitivity, 100%; specificity, 88%) and 0.29 microg/dl (sensitivity, 100%; specificity, 71%) using RIA. When the findings were compared to those obtained from low dose dexamethasone test, both ECLIA and RIA of MSC showed a better diagnostic performance. CONCLUSION: MSC measurement is useful for the diagnosis of overt hypercortisolism but the cutoff value is highly dependent on the method used. We recommend the use of automated ECLIA for MSC assay, and we propose further studies on other automated immunoassay analyzers potentially suitable for MSC measurements.

[Outcome of somatostatin analogue treatment in acromegaly]. / A szomatosztatinanalóg kezelés eredményei acromegaliában.

UNLABELLED: During the past decade the importance of medical therapy, especially treatment with somatostatin analogues has increased significantly in patients with active acromegaly. AIMS: Authors analyzed the outcome of somatostatin analogue treatment in acromegalic patients evaluated and followed up at the 2nd Department of Medicine, Faculty of Medicine, Semmelweis University, during the past 10 years. PATIENTS AND METHODS: Changes in serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentration, as well as morphologic changes of pituitary adenomas followed by MRI scans were evaluated and compared in 32 acromegalic patients (26 women, 6 men) during long-term somatostatin analogue treatment (mean+/-SE, 3.1+/-0.3 years, range, 1-7 years). Primary somatostatin analogue treatment was applied in 10 patients (7 women and 3 men), whereas 15 patients (14 women and 1 man) had pituitary surgery and 7 patients (5 women and 2 men) underwent both pituitary surgery and irradiation therapy prior to somatostatin analogue treatment. RESULTS: After a 3-month treatment with somatostatin analogues, both serum GH and IGF-1 levels decreased significantly and they remained around the same decreased levels throughout the treatment period. Serum GH decreased from 15.7+/-4.9 to 5.5+/-1.4 ng/ml, and serum IGF-1, expressed as a percentage of the upper limit of age- and sex-adjusted reference value, decreased from 204+/-14% to 135+/-12% at the end of treatment. The efficacy of somatostatin analogue treatment was not influenced by surgical or surgical and irradiation therapies which were applied prior to medical treatment. At the end of treatment 36.7% of patients had safe serum GH (<2.5 ng/ml), while serum IGF-1 returned below the upper limit of age- and sex-adjusted reference range in 41.4% of patients. Pituitary MRI showed regression of the adenoma in 46% of patients, and none of the patients had progression of the pituitary adenoma. CONCLUSIONS: Somatostatin analogues are effective therapeutic options for acromegalic patients when primary surgical treatment cannot be performed due to complications and associated disorders, or in patients whose acromegaly remains active after pituitary surgery or after pituitary surgery and irradiation.

Germline VHL gene mutations in Hungarian families with von Hippel-Lindau disease and patients with apparently sporadic unilateral pheochromocytomas.

OBJECTIVE: Von Hippel-Lindau (VHL) disease is a hereditary tumor syndrome caused by mutations or deletions of the VHL tumor-suppressor gene. Germline VHL gene alterations may be also present in patients with apparently sporadic pheochromocytoma (ASP), although a wide variation in mutation frequencies has been reported in different patient cohorts. DESIGN: Herein, we report the analysis of the VHL gene in Hungarian families with VHL disease and in those with ASP. METHODS: Seven families (35 members) with VHL disease and 37 unrelated patients with unilateral ASP were analyzed. Patients were clinically evaluated and the VHL gene was analyzed using direct sequencing, multiplex ligation-dependent probe amplification, and real-time PCR with SYBR Green chemistry. RESULTS: Disease-causing genetic abnormalities were identified in each of the seven VHL families and in 3 out of the 37 patients with ASP (one nonsense and six missense mutations, two large gene deletions and one novel 2 bp deletion). Large gene deletions and other genetic alterations resulting in truncated VHL protein were found only in families with VHL type 1, whereas missense mutations were associated mainly, although not exclusively, with VHL type 2B and type 2C. CONCLUSIONS: The spectrum of VHL gene abnormalities in the Hungarian population is similar to that observed in Western, Japanese, or Chinese VHL kindreds. The presence of VHL gene mutations in 3 out of the 37 patients with ASP suggests that genetic testing is useful not only in patients with VHL disease but also in those with ASP.

11beta-hydroxysteroid dehydrogenase activity in acromegalic patients with normal or impaired carbohydrate metabolism.

The 11beta-hydroxysteroid dehydrogenase isoenzymes (11beta-HSD) catalyse the interconversion of cortisol (F) and cortisone (E). Earlier studies demonstrated that growth hormone (GH) and insulin resistance may exert opposite effects on the conversion of E to F by 11beta-HSD type 1. Therefore, in the present study we determined F and E concentrations in 562 plasma samples obtained from acromegalic patients during an active phase (76 patients) and after cure of the disease (68 patients). In addition, we examined whether type 2 diabetes mellitus or impaired glucose tolerance, which are frequently associated with active acromegaly could influence plasma F and E levels in these patients. We found that plasma F concentrations were similar in patients with active acromegaly and in those who were cured with pituitary surgery, irradiation and/or medical therapy (mean+/-S.E., 12.4+/-0.3 and 12.7+/-0.4 microg/dl, respectively). However, plasma E levels were significantly higher in patients with active compared to those with cured acromegaly (2.8+/-0.1 and 2.2+/-0.1 microg/dl, respectively; p<0.001), resulting in a lower F/E ratio in patients with active disease (4.6+/-0.1 vs. 5.9+/-0.2 in the cured group of patients; p<0.001). When the effect of altered carbohydrate homeostasis on plasma F and E was analysed, the results indicated significantly lower plasma E levels and higher F/E ratios in active acromegalic patients with type 2 diabetes mellitus or impaired glucose tolerance compared to those with normal carbohydrate metabolism (E, 2.5+/-0.1 and 3.0+/-0.1 microg/dl, respectively; F/E, 5.1+/-0.2 and 4.4+/-0.1; p<0.001), whereas plasma F concentrations were similar in these two groups (12.1+/-0.4 and 12.6+/-0.3 microg/dl, respectively). These findings indicate that disease activity exerts a significant impact on 11beta-HSD in acromegalic patients, which is further modified with altered carbohydrate homeostasis, frequently present in patients with active disease.

Atherosclerotic risk factors and complications in patients with non-functioning adrenal adenomas treated with or without adrenalectomy: a long-term follow-up study.

OBJECTIVE: Despite the increased prevalences of hypertension, type 2 diabetes mellitus (T2DM), hyperlipidemy, and obesity in patients with non-functioning adrenal adenomas (NFAAs), there is a paucity of data on long-term atherosclerotic morbidity as well as the long-term cardiovascular effects of adrenalectomy in these patients. DESIGN, PATIENTS, AND METHODS: This retrospective study includes the results of baseline and follow-up investigations of 125 patients (29 males and 96 females; mean age 60.1 years) with NFAAs referred for endocrine evaluation between 1990 and 2001. Of the 125 patients, 47 underwent unilateral adrenalectomy, while 78 patients were followed conservatively. These patients were reinvestigated after a mean follow-up time of 9.1 (5-16) years in 2006, with special emphasis on laboratory and other atherosclerotic risk factors (ARF), vascular events, and interventions. RESULTS: The prevalences of hypertension, impaired glucose tolerance or T2DM, hyperlipidemy, and obesity were 82, 43, 58, and 50%, and 89, 58, 82, and 50% at baseline and follow-up, respectively. None of the investigated ARF prevalences were different between patients treated and not treated with adrenalectomy, and between patients with and without subclinical Cushing's syndrome. The prevalences of angina pectoris, acute myocardial infarction, coronary, and peripheral arterial interventions or cerebrovascular stroke did not differ significantly between patients treated and not treated with adrenalectomy. CONCLUSION: Our study confirms previous investigations reporting markedly increased prevalences of various ARF in patients with NFAAs. Adrenalectomy performed in these patients failed to decrease the prevalence of ARF and atherosclerotic morbidity.

[Evaluation of the accuracy of inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome]. / Sinus petrosus inferior katéterezés értékelése az adrenokortikotrop hormon dependens Cushing-szindróma elkülöníto diagnosztikájában.

The differentiation of adrenocorticotropic hormone producing pituitary adenoma (Cushing's disease) from the ectopic ACTH syndrome is always a complex and difficult task, and in rare cases it is not possible to differentiate between the two disorders, even with the use of dynamic endocrine tests and the most advanced imaging techniques. Inferior petrosal sinus sampling (IPSS) with subsequent ACTH measurements became the gold-standard method of the differential diagnostic process. 34 patients with ACTH dependent Cushing's syndrome in whom the source of ACTH secretion couldn't be identified unambiguously with imaging techniques and/or dynamic endocrine tests underwent altogether 41 IPSS between 1999 and 2005. The sensitivity of the method was calculated on the basis of 31 samplings of 25 patients who had definite endocrinological diagnosis confirmed by the recovery from Cushing's syndrome after surgical intervention and/or by histological examinations (22 patients with ACTH-producing pituitary adenoma and 3 patients with ectopic ACTH syndrome). As a result of IPSS, pituitary-dependent Cushing's disease was diagnosed with a baseline central to peripheral ACTH ratio of >2.0 or with a ratio of >3.0 after corticotropin releasing hormone (CRH) administration. IPSS correctly identified ACTH-producing pituitary adenoma in 20 of 28 sampling procedures, with a sensitivity of 71.4%. Three patients had true negative and 8 had false negative results. There was no false positive result. Four of the 8 patients with false negative first sampling had a repeat sampling procedure leading to true positive result in each patient. In patients with Cushing's disease having true positive interventions, the basal and 5 minutes post-CRH ACTH concentrations were diagnostic in 14 and 19 cases, respectively. The sensitivity of IPSS within this series, reported for the first time from Hungary, was lower than it was found in much larger series published in international literature. In addition to technical difficulties, the lower sensitivity can be accounted also for the highly selected nature of the patient group.

[Treatment of iatrogenic Cushing syndrome: questions of glucocorticoid withdrawal]. / A iatrogén Cushing-szindróma kezelése: a glükokortikoid terápia leépítésének kérdései.

Iatrogenic Cushing's syndrome is the most common form of hypercortisolism. Glucocorticoids are widely used for the treatment of various diseases, often in high doses that may lead to the development of severe hypercortisolism. Iatrogenic hypercortisolism is unique, as the application of exogenous glucocorticoids leads to the simultaneous presence of symptoms specific for hypercortisolism and the suppression of the endogenous hypothalamic-pituitary-adrenal axis. The principal question of its therapy is related to the problem of glucocorticoid withdrawal. There is considerable interindividual variability in the suppression and recovery of the hypothalamic-pituitary-adrenal axis, therefore, glucocorticoid withdrawal and substitution can only be conducted in a stepwise manner with careful clinical follow-up and regular laboratory examinations regarding endogenous hypothalamic-pituitary-adrenal axis activity. Three major complications which can be associated with glucocorticoid withdrawal are: i. reactivation of the underlying disease, ii. secondary adrenal insufficiency, iii. steroid withdrawal syndrome. Here, the authors summarize the most important aspects of this area based on their clinical experience and the available literature data.

[Radiotherapy of pituitary tumours]. / A hypophysisdaganatok radioteráipiáija.

In this article, the role of conventional radiotherapy and radiosurgery in the management of pituitary tumors is discussed. After a brief review about the mechanism of action and different techniques of irradiation therapy, the therapeutic effectiveness and side effects are analysed in the various types of pituitary tumors. Conventional fractionated radiotherapy has long been used to control growth and/or hormonal secretion of residual or recurrent pituitary tumors. Nevertheless, there is still a controversy concerning patient selection for radiotherapy, because several potentially significant side effects including hypopituitarism may develop. Stereotactic radiosurgical methods may have several advantages over conventional radiotherapy; they can be applied, for example, in patients with residual or recurrent pituitary tumors who had previously received conventional radiotherapy. However, long-term follow-up data with these relatively new techniques are still limited.

[Diagnosis and treatment outcome in primary aldosteronism based on a retrospective analysis of 187 cases]. / A primer aldosteronismus diagnosztikája és a kezelés eredményei 187 beteg adatainak retrospektív elemzése alapján.

INTRODUCTION: Primary aldosteronism is the most common form of mineralocorticoid hypertension. The disease has been described by Jerome W. Conn in 1955; since that time there has been a great progress in the knowledge concerning the prevalence, diagnostics and treatment of the disease. AIMS: The authors retrospectively analyzed the efficacy of diagnostic procedures and the outcome of treatment by the analysis of data of 187 patients with primary aldosteronism examined between 1958 and 2004 at the 2nd Department of Medicine of Semmelweis University. METHODS: The efficacy of different methods used for the diagnosis, the frequency of the different subtypes of primary aldosteronism, as well as the surgical outcomes in patients with surgically treated subtypes of primary aldosteronism were studied. RESULTS: Aldosterone-producing adenoma was detected in more than two thirds of patients (n = 135), whereas idiopathic hyperaldosteronism was found in 46 patients. Other subtypes of primary hyperaldosteronism occurred less frequently (unilateral primary adrenocortical hyperplasia in 5 patients and adrenocortical carcinoma in one patient). For the diagnosis of familial hyperaldosteronism type I, molecular biological studies of the aldosterone-synthase/11beta-hydroxylase gene chimera were carried out in 30 patients but none of them showed the presence of the chimeric gene. When comparing the clinical parameters of patients with aldosterone-producing adenoma and idiopathic hyperaldosteronism, no significant differences were found in the time period between the diagnosis of hypertension and the diagnosis of primary aldosteronism, or in the systolic and diastolic blood pressure values. The mean of the lowest documented serum potassium concentration was slightly lower in patients with aldosterone-producing adenoma (2.8 +/- 0.1 mmol/l) compared to those with idiopathic hyperaldosteronism (3.1 +/- 0.2 mmol/l), but the difference was not significant. Normokalemic primary hyperaldosteronism was found in 7 cases. The ratio of plasma aldosterone concentration (ng/dl) to plasma renin activity (ng/ml/h) was above 20 in all patients with aldosterone-producing adenoma and in all but 5 cases with idiopathic hyperaldosteronism. To confirm the diagnosis and to differentiate the subtypes of primary aldosteronism, the postural test combined with furosemide administration was performed in the majority of patients. When cases showing an elevation of plasma cortisol level during the test were excluded, this test differentiated patients with aldosterone-producing adenoma from those with idiopathic hyperaldosteronism with a sensitivity of 69% and a specificity of 92%. In cases of adrenocortical adenomas not or not clearly detectable by radiological imaging techniques, as well as in cases with bilateral adrenocortical adenomas, selective adrenal vein sampling was performed (n = 55). All but 4 patients with aldosterone-producing adenoma underwent adrenalectomy. Histology and postoperative hormone results confirmed the preoperative diagnosis in all operated patients. After surgery serum potassium concentration returned to normal in all patients showing low serum potassium levels before surgery. Also, the moderate to severe preoperative hypertension disappeared or improved after surgery. CONCLUSIONS: These observations are in contrast with the results of international studies which showed a high frequency of normokalemic primary aldosteronism and a more frequent occurrence of idiopathic hyperaldosteronism well treatable with aldosterone-antagonists. Therefore, it can be presumed that a significant number of primary aldosteronism cases that are not accompanied with severe hypokalemia remain undetected in Hungary.

[Nucleotide sequence variants of the glucocorticoid receptor gene and their significance in determining glucocorticoid sensitivity]. / A glükokortikoidreceptor gén szekvenciavariánsai és jelentoségük a glükokortikoidok iráinti érzékenység meghatározásában.

Nucleotide sequence variants of the glucocorticoid receptor gene and their significance in determining glucocorticoid sensitivity. The physiologic response and sensitivity to glucocorticoids may significantly differ among species, individuals, tissues and cell types. The variability of the effect of endogenous and exogenous glucocorticoids is largely determined by genetic components, of which the authors review the knowledge on the glucocorticoid receptor gene. The authors describe the genomic and non-genomic pathways of receptor function, the significance of isoforms produced during receptor protein formation, the pathomechanism of glucocorticoid resistance syndrome and the results of clinical investigations related to receptor gene polymorphisms. Through subtle alteration of receptor function, the gene polymorphisms may increase or diminish sensitivity to glucocorticoids and may play a role in the pathogenesis of metabolic disorders. In their own studies the authors found, that the N363S polymorphism, which increases glucocorticoid sensitivity, may play a role in the pathogenesis of bilateral adrenal adenomas, it may modify the clinical phenotype of patients with congenital adrenal hyperplasia, and may have an impact on steroid-induced ocular hypertension. It is presumed that further research in other diseases will continue to complete our knowledge on the pathophysiology of glucocorticoid receptor gene polymorphisms.

[Clinical symptoms, diagnosis and treatment of multiple endocrine neoplasia type 1. Results of genetic screening in Hungarian patients]. / Az 1-es típusú multiplex endokrin neoplasia klinikai tünetei, diagnózisa és kezelése. A genetikai vizsgálatok hazai tapasztalatai.

Multiple endocrine neoplasia type 1 syndrome is an autosomal dominant disorder characterized by endocrinopathies involving the parathyroid glands, anterior pituitary gland, and pancreas. Also, it may be associated with foregut carcinoid, adrenocortical tumors and non-endocrine tumors. After reviewing the prevalence, genetic background, clinical symptoms, diagnosis and treatment of the disorder, the authors present their genetic screening method used for the detection of mutations of the MEN1 gene (prescreening of polymerase chain reaction amplified exons using temporal temperature gradient gel electrophoresis followed by direct DNA sequencing). Using this method, the authors identified disease-causing MEN1 gene mutations in 9 probands (small deletions in 2 cases, insertion in 2 cases, nonsense mutations in 2 cases and missense mutations in 3 cases). Of the 9 mutations, 4 proved to be novel mutation not reported in the literature. Family screening indicated de novo mutations in 2 probands. In addition to mutations, several sequence polymorphisms were also detected. The authors conclude that one of the major advantages of genetic screening in families with MEN1 syndrome was the identification of family members carrying the mutation who should be regularly screened for disease manifestations and those not carrying the mutation in whom clinical screening is unnecessary. Also, genetic screening may be useful in cases when MEN1 syndrome is suspected, but the clinical manifestations do not fully establish the diagnosis of MEN1 syndrome.

Treatment of pituitary tumors: radiation.

In this paper, the role of conventional radiotherapy and radiosurgery in the management of pituitary tumors is reviewed. After a short summary of the mechanism of action of irradiation therapy and the types of different irradiation techniques, the therapeutic effects and side effects are analyzed in patients with different types of pituitary tumors, including our own experience with conventional radiotherapy and radiosurgery in patients with acromegaly. Conventional fractionated radiotherapy has long been used to control growth and/or hormonal secretion of residual or recurrent pituitary tumors. However, patient selection for conventional radiotherapy still remains a controversial issue, because a number of potentially significant side effects, including hypopituitarism and other complications, have been described. Stereotactic radiotherapy/radiosurgery methods have several potential advantages over conventional radiotherapy, including their use in patients with residual or recurrent pituitary tumors who had previously been treated by conventional radiotherapy, but long-term follow-up data with these relatively new techniques are still limited.

Novel mutation of the CYP17 gene in two unrelated patients with combined 17alpha-hydroxylase/17,20-lyase deficiency: demonstration of absent enzyme activity by expressing the mutant CYP17 gene and by three-dimensional modeling.

The CYP17 gene, located on chromosome 10q24-q25, encodes the cytochrome P450c17 enzyme. Mutations of this gene cause the 17alpha-hydroxylase/17,20-lyase deficiency, which is a rare, autosomal recessive form of congenital adrenal hyperplasia. Approximately 50 different mutations of the CYP17 gene have been described, of which some mutations have been identified in certain ethnic groups. In this study, we present the clinical history, hormonal findings and mutational analysis of two patients from unrelated families, who were evaluated for hypertension, hypokalemia and sexual infantilism. In the first patient, who was a 37-year-old female, additional studies showed a large myelolipoma in the left adrenal gland, and a smaller tumor in the right adrenal gland. In the second patient, who was a 31-year-old phenotypic female, clinical work-up revealed a 46,XY kariotype, absence of ovaries and presence of testes located in the inner opening of both inguinal canals. Analysis of the CYP17 gene by polymerase chain reaction amplification and direct sequencing demonstrated a novel homozygous mutation of codon 440 from CGC (Arg) to TGC (Cys) in both patients. The effect of this novel mutation on 17alpha-hydroxylase/17,20-lyase activity was assessed by in vitro studies on the mutant and wild-type P450c17 generated by site-directed mutagenesis and transfected in nonsteroidogenic COS-1 cells. These studies showed that the mutant P450c17 protein was produced in transfected COS-1 cells, but it had negligible 17alpha-hydroxylase and 17,20-lyase activities. In addition, three-dimensional computerized modeling of the heme-binding site of the P450c17 enzyme indicated that replacement of Arg by Cys at amino acid position 440 predicts a loss of the catalytic activity of the enzyme, as the mutant enzyme containing Cys440 fails to form a hydrogen bond with the propionate group of heme, which renders the mutant enzyme unable to stabilize the proper position of heme. Based on these findings we conclude that expressing the CYP17 gene with functional analysis, combined with three-dimensional computerized modeling of the heme-binding site of the protein provide feasible tools for molecular characterizing of functional consequences of the novel CYP17 mutation on enzyme function.

[Oncocytic tumor of the adrenal gland]. / Oncocytás mellékvese-adenoma.

Oncocytic tumor of the adrenal gland. The authors describe a case of a rare tumor arising in the adrenal gland. The tumor 6 cm in diameter, connected to the right adrenal gland, was found incidentally in a healthy young man of 34 years of age, who suffered an accident and had a rib fracture. No pathological hormone production was detected on laboratory tests. The right adrenal gland with the tumor was removed by laparoscopic surgery. Histopathological examination revealed an oncocytic adenoma of the adrenal cortex. The authors describe the morphology and the differential diagnosis of this rare tumor of the adrenal gland.