Liver adenomatosis in patients with hepatocyte nuclear factor-1 alpha maturity onset diabetes of the young (HNF1A-MODY): Clinical, radiological and pathological characteristics in a French series.

BACKGROUND: Liver adenomatosis (LA) is a rare disease resulting from biallelic inactivation of the hepatocyte nuclear factor-1 alpha (HNF1A) gene, which induces the proliferation of adenoma cells in liver parenchyma. Liver adenomatosis has only been documented in case reports from patients carrying a HNF1A germline mutation. We have evaluated the frequency of LA among a large cohort of patients with HNF1A-maturity onset diabetes of the young (MODY), previously termed "MODY3," and herein describe its clinical, radiological, and pathological characteristics. METHODS: In all, 137 HNF1A-MODY subjects from 74 families were screened by liver ultrasonography in 13 centers, and 15 additional cases of LA were later included in the series. Liver adenomatosis was confirmed by liver computed tomography, magnetic resonance imaging (MRI), and/or histopathology. RESULTS: Among 137 carriers of an HNF1A mutation, 9 patients (6.5%) from seven families were diagnosed with LA. Diabetes mellitus was present in 87.5% of patients with LA. In 25% of patients, LA was diagnosed due to intra-abdominal or intratumoral bleeding. Liver biochemistry was near normal in all patients. Liver imaging showed adenomas of various sizes and numbers. On MRI, most nodules had the radiological characteristics of steatotic adenomas. Histopathological confirmation of LA was available in 13 cases, and these adenomas were mostly steatotic. Surgery was initially performed in 37.5% of patients, and liver disease progression was observed in 30%. No disease progression was observed in 14 pregnancies. CONCLUSIONS: The frequency of LA in a cohort of screened HNF1A-MODY patients and the high incidence of LA progression and/or hemorrhage warrants systematic screening for liver adenomatosis in HNF1A-MODY families.

Long-term results of the surgical management of insulinoma patients with MEN1: a Groupe d'étude des Tumeurs Endocrines (GTE) retrospective study.

OBJECTIVE: Management of insulinomas in the context of MEN1 remains poorly studied. The aim of this study was to evaluate long-term results of various surgical approaches in a large cohort of insulinoma-MEN1 patients. DESIGN AND METHODS: Consecutive insulinoma-MEN1 patients operated on for a nonmetastatic insulinoma between 1957 and 2010 were retrospectively selected from the MEN1 database of the French Endocrine Tumor Group. The type of surgery was categorized as distal pancreatectomy (DP), total pancreatectomy/cephalic duodenopancreatectomy (TP/CDP), or enucleation (E). Primary endpoint was time until recurrence of hypoglycemia after initial surgery. Secondary endpoints were post-operative complications. RESULTS: The study included 73 patients (median age=28 years). Surgical procedures were DP (n=46), TP/CDP (n=9), or E (n=18). After a median post-operative follow-up of 9.0 years (inter-quartile range (IQR): 2.5-16.5 years), 60/73 patients (82.2%) remained hypoglycemia free. E and TP/CDP were associated with a higher risk of recurrent hypoglycemia episodes (unadjusted hazard ratio: 6.18 ((95% CI: 1.54-24.8); P=0.010) for E vs DP and 9.51 ((95% CI: 1.85-48.8); P=0.007) for TP/CDP vs DP. After adjustment for International Union against Cancer pTNM classification, enucleation remained significantly associated with a higher probability of recurrence. Long-term complications had occurred in 20 (43.5%) patients with DP, five (55.6%) with TP/CDP, but in none of the patients who have undergone E (P=0.002). CONCLUSION: In the French Endocrine database, DP is associated with a lower risk for recurrent hypoglycemia episodes. Due to lower morbidity, E alone might be considered as an alternative.

Expression and regulation of INTELECTIN1 in human granulosa-lutein cells: role in IGF-1-induced steroidogenesis through NAMPT.

INTELECTIN (ITLN) is an adipokine involved in the regulation of insulin sensitivity and inflammatory and immunity responses. Serum ITLN levels are lower in obese, diabetic, and polycystic ovary syndrome (PCOS) women than in control subjects. ITLN has never been studied in ovarian cells. Here, we identified ITLN1 in human ovarian follicles and investigated the molecular mechanisms involved in the regulation of its expression in response to the insulin sensitizers metformin and rosiglitazone, in human granulosa-lutein cells (hGLCs) and in a human ovarian granulosa-like tumor cell line (KGN). We also studied the effects of human recombinant ITLN1 (hRom1) on steroid production and on the activation of various signaling pathways. Using RT-PCR, immunoblotting, and immunohistochemistry, we found that INTL1 is present in human follicular cells. Using ELISA, we showed that INTL levels are similar in plasma and follicular fluid (FF) in control patients, whereas they are higher in FF than in plasma in PCOS patients. In KGN cells and hGLCs, insulin (10(-8) M), insulin-like growth factor-1 (IGF-1; 10(-8) M), and metformin (10(-2) M or 10(-3) M) increased INTL1 expression (mRNA and protein) after 12 and 24 h of stimulation. For metformin, this effect was mediated by adenosine monophosphate-activated kinase (PRKA). Furthermore, hRom1 increased nicotinamide phosphoribosyltransferase (NAMPT) expression in KGN and hGLCs. We also showed that hRom1 increased IGF-1-induced progesterone and estradiol secretion and this was associated with an increase in the STAR and CYP19A1 protein levels and an increase in IGF-1R signaling. Furthermore, all these data were abolished when NAMPT was knocked down in KGN cells, suggesting that INTL1 improves IGF-1-induced steroidogenesis through induction of NAMPT in hGLCs.

Higher risk of death among MEN1 patients with mutations in the JunD interacting domain: a Groupe d'etude des Tumeurs Endocrines (GTE) cohort study.

Multiple endocrine neoplasia syndrome type 1 (MEN1), which is secondary to mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Although genotype-phenotype studies have so far failed to identify any statistical correlations, some families harbor recurrent tumor patterns. The function of MENIN is unclear, but has been described through the discovery of its interacting partners. Mutations in the interacting domains of MENIN functional partners have been shown to directly alter its regulation abilities. We report on a cohort of MEN1 patients from the Groupe d'étude des Tumeurs Endocrines. Patients with a molecular diagnosis and a clinical follow-up, totaling 262 families and 806 patients, were included. Associations between mutation type, location or interacting factors of the MENIN protein and death as well as the occurrence of MEN1-related tumors were tested using a frailty Cox model to adjust for potential heterogeneity across families. Accounting for the heterogeneity across families, the overall risk of death was significantly higher when mutations affected the JunD interacting domain (adjusted HR = 1.88: 95%-CI = 1.15-3.07). Patients had a higher risk of death from cancers of the MEN1 spectrum (HR = 2.34; 95%-CI = 1.23-4.43). This genotype-phenotype correlation study confirmed the lack of direct genotype-phenotype correlations. However, patients with mutations affecting the JunD interacting domain had a higher risk of death secondary to a MEN1 tumor and should thus be considered for surgical indications, genetic counseling and follow-up.

Adrenal rest tissue in gonads of patients with classical congenital adrenal hyperplasia: multicenter study of 45 French male patients.

OBJECTIVES: Several cases of testicular adrenal rest tumours have been reported in men with congenital adrenal hyperplasia (CAH) due to the classical form of 21-hydroxylase deficiency but the prevalence has not been established. The aims of this report were to evaluate the frequency of testicular adrenal rest tissue in this population in a retrospective multicentre study involving eight endocrinology centres, and to determine whether treatment or genetic background had an impact on the occurrence of adrenal rest tissue. MATERIAL AND METHODS: Testicular adrenal rest tissue (TART) was sought clinically and with ultrasound examination in forty-five males with CAH due to the classical form of 21-hydroxylase deficiency. When the diagnosis of testicular adrenal rest tumours was sought, good observance of treatment was judged on biological concentrations of 17-hydroxyprogesterone (17OHP), delta4-androstenedione, active renin and testosterone. The results of affected and non-affected subjects were compared. RESULTS: TART was detected in none of the 18 subjects aged 1 to 15years but was detected in 14 of the 27 subjects aged more than 15years. Five patients with an abnormal echography result had no clinical signs. Therapeutic control evaluated at diagnosis of TART seemed less effective when diagnosis was made in patients with adrenal rest tissue compared to TART-free subjects. Various genotypes were observed in patients with or without TART. CONCLUSION: Due to the high prevalence of TART in classical CAH and the delayed clinical diagnosis, testicular ultrasonography must be performed before puberty and thereafter regularly during adulthood even if the clinical examination is normal.

PROKR2 variants in multiple hypopituitarism with pituitary stalk interruption.

CONTEXT: Pituitary stalk interruption represents a frequent feature of congenital hypopituitarism, but only rare cases have been assigned to a known genetic cause. OBJECTIVE: Using a candidate gene approach, we tested several genes as potential causes of hypopituitarism with pituitary stalk interruption. We hypothesized that ectopic posterior pituitary may be a consequence of defective neuronal axon projections along the pituitary stalk or defective angiogenesis of hypophyseal portal circulation. Considering the role of the prokineticin 2 pathway in angiogenesis and neuronal migration, we screened PROK2 and PROKR2 genes. DESIGN: PROK2 and PROKR2 and all genes previously known to be involved in hypopituitarism with pituitary stalk interruption (LHX4, HESX1, OTX2, and SOX3) were screened in 72 index cases with pituitary stalk interruption syndrome from the GENHYPOPIT database. In vitro studies were performed to assess the functional consequences of allelic variants. RESULTS: We identified two heterozygous PROKR2 mutations (p.Leu173Arg and p.Arg85His) previously reported in isolated hypogonadotroph hypogonadism and a novel PROKR2 variant (p.Ala51Thr) that, in contrast with both other mutations, did not impair receptor signaling activity. Three allelic variants of HESX1 were identified: the heterozygous p.Phe156Ser and the homozygous p.Arg109X mutations were functionally deleterious, whereas p.Ser67Thr was found as a rare allelic variant in association with p.Arg85His PROKR2 mutation in the same patient. CONCLUSIONS: We report PROKR2 variants in congenital hypopituitarism with pituitary stalk interruption, suggesting a potential role of the prokineticin pathway in pituitary development.

Cyclin-dependent kinase inhibitor 1B (CDKN1B) gene variants in AIP mutation-negative familial isolated pituitary adenoma kindreds.

Familial isolated pituitary adenoma (FIPA) occurs in families and is unrelated to multiple endocrine neoplasia type 1 and Carney complex. Mutations in AIP account only for 15-25% of FIPA families. CDKN1B mutations cause MEN4 in which affected patients can suffer from pituitary adenomas. With this study, we wanted to assess whether mutations in CDKN1B occur among a large cohort of AIP mutation-negative FIPA kindreds. Eighty-eight AIP mutation-negative FIPA families were studied and 124 affected subjects underwent sequencing of CDKN1B. Functional analysis of putative CDKN1B mutations was performed using in silico and in vitro approaches. Germline CDKN1B analysis revealed two nucleotide changes: c.286A>C (p.K96Q) and c.356T>C (p.I119T). In vitro, the K96Q change decreased p27 affinity for Grb2 but did not segregate with pituitary adenoma in the FIPA kindred. The I119T substitution occurred in a female patient with acromegaly. p27(I119T) shows an abnormal migration pattern by SDS-PAGE. Three variants (p.S56T, p.T142T, and c.605+36C>T) are likely nonpathogenic because In vitro effects were not seen. In conclusion, two patients had germline sequence changes in CDKN1B, which led to functional alterations in the encoded p27 proteins in vitro. Such rare CDKN1B variants may contribute to the development of pituitary adenomas, but their low incidence and lack of clear segregation with affected patients make CDKN1B sequencing unlikely to be of use in routine genetic investigation of FIPA kindreds. However, further characterization of the role of CDKN1B in pituitary tumorigenesis in these and other cases could help clarify the clinicopathological profile of MEN4.

Von Hippel-Lindau disease and aggressive GH-PRL pituitary adenoma in a young boy.

Von Hippel-Lindau disease is an autosomal dominant disorder involving the development of specific tumours in multiple organs, both benign and malignant. In the CNS, the syndrome is characterized by haemangioblastomas of the retina, spinal cord and brain. We report the case of a 15-year-old boy with the diagnosis of aggressive GH-PRL pituitary macroadenoma and a family history of VHL disease. Pituitary resection was performed, although complete excision of the lesion could not be confirmed by the neurosurgeon. A control MRI was done 6 months after surgery and the pituitary lesion was similar to the presurgical image. A second operation allowed partial resection of the tumour followed by targeted radiotherapy. Pituitary adenomas are rare benign tumours in children with macroadenomas observed mainly in boys. These tumours in adolescents often occur in a familial setting or in the context of known genetic defects. Angiogenesis is an important feature of pituitary adenomas and a possible inhibitory role of pVHL in pituitary angiogenesis has been suggested. This GH-PRL pituitary macroadenoma with a VHL mutation might be of particular aggressiveness. Pituitary adenomas are not classically described in VHL syndrome and the medical community should be alerted to its rare occurrence in this location.

A novel mutation in the calcium-sensing receptor in a French family with familial hypocalciuric hypercalcaemia.

OBJECTIVE: The calcium-sensing receptor (CASR) has an important role in calcium homoeostasis by controlling PTH secretion and renal calcium handling. Inactivating mutations in the CASR gene (HGNC ID: 1514) cause familial hypocalciuric hypercalcaemia (FHH). We present a case of FHH patient to describe a novel mutation in the CASR. SUBJECTS AND METHODS: A 34-year-old patient was referred because of recurrent hypercalcaemia after resection of two hyperplastic parathyroids. Extensive evaluation found elevated PTH and low calcium/creatinine clearance ratio. One of her three children had high serum calcium concentrations. Genetic studies were performed by PCR amplification of CASR coding exons and direct sequencing of PCR products. Transient transfection of the wild-type (WT) CASR and the mutant CASR into COS-7 was performed to assess functional impact of the mutation and the capacity of either protein to mediate increases in cellular levels of inositol phosphates (IPs). RESULTS: CASR sequencing found a previously undescribed heterozygous base substitution, determining a change of threonine to isoleucine at codon 550 (p.T550I) in the sixth exon. In contrast to those transfected with WT CASR, which showed a five- to eightfold increase in total IPs at high levels of calcium, COS-7 cells transfected with the (p.T550I) mutant showed no increase confirming to the inactivating nature of the mutation. COS-7 cells co-transfected with the WT and the (p.T550I) mutant showed an intermediate response suggesting a possible dominant negative effect. CONCLUSION: This case report presents a not-yet-described mutation in the cysteine-rich region of the CASR extracellular domain, a mutation with a possible dominant negative effect.

Low high density lipoprotein cholesterol: prevalence and associated risk-factors in a large French population.

PURPOSE: High density lipoprotein-cholesterol (HDL-C) is a strong predictor of cardiovascular risk. We investigated the distribution of HDL-C in a French general population according to age, sex, and the risk factors associated with low HDL-C values. METHODS: A group of 18,483 men and 22,047 women 16-79 years of age were investigated during a medical check-up. Relevant parameters were studied in three groups according to age and gender-specific percentile classes (≤5th [HDL5] median and >95th). Gender-specific logistic regression models selected variables associated with HDL5. RESULTS: Using the National Cholesterol Education Program Adult Treatment Panel III criteria (threshold: 40 mg/dL in men, 50 mg/dL in women) the prevalence of low HDL-C was 11.1% and 26.4% in men and women and it decreased with age. Mean HDL-C levels increased with age. HDL5 was positively associated with a sedentary lifestyle and deprivation (p < 0.00001) even after adjustment on alcohol consumption and smoking. Abdominal obesity, smoking, hypertriglyceridemia, hyperleucocytosis, and low alcohol consumption were associated with HDL5 for both genders. CONCLUSIONS: The prevalence of low HDL-C was similar to that observed in other Europeans but lower than in the United States. HDL5 was associated with cardiovascular risk factors, metabolic syndrome, and social deprivation. A prevention policy to increase HDL-C levels should focus on reducing smoking and abdominal obesity, particularly in deprived subjects.

[BRAF V600E mutation in papillary thyroid carcinoma: prevalence and detection in fine needle aspiration specimens]. / Mutation BRAF V600E et carcinomes papillaires de la thyroïde : prévalence et faisabilité de la détection sur produits de cytoponction.

UNLABELLED: BRAF V600E mutation in papillary thyroid carcinoma (PTC): prevalence and detection in fine needle aspiration (FNA) specimens. BACKGROUND AND OBJECTIVE: The activating mutation of the BRAF gene, T1799A, is the most common and specific genetic alteration in PTC. In the present study, our aims were to confirm these data and investigate the feasibility of BRAF mutation detection in FNA specimens. METHODS: In a retrospective study, we examined paraffin-embedded surgical samples of 57 PTC and 51 non-PTC thyroid tumors for the presence of BRAF mutation by dideoxy sequencing. We analyzed thyroid aspirates (drop and washed-out solution) and smears from 31 patients who underwent thyroidectomy, before intraoperative frozen sections, and 25 archival thyroid FNA smears. RESULTS: The BRAF mutation was present in 58 % of PTC. Among non-PTC thyroid tumors, only one medullary thyroid carcinoma contained the BRAF mutation. BRAF mutation was correctly detected from the FNA-derived materials. Considering the search of BRAF mutation in preoperative FNA smears, the diagnosis of PTC would have been affirmed in 31 % (4/13) of indeterminate and suspicious FNA. CONCLUSION: BRAF mutation detection in FNA specimens is feasible and could be used as an adjunct tool for preoperative diagnosis of PTC classified as indeterminate and suspicious with conventional cytology (categories 3, 4 and 5 according to NCI/Bethesda 2008 terminology).

The succinate dehydrogenase genetic testing in a large prospective series of patients with paragangliomas.

CONTEXT: Germline mutations in SDHx genes cause hereditary paraganglioma. OBJECTIVE: The aim of the study was to assess the indications for succinate dehydrogenase (SDH) genetic testing in a prospective study. DESIGN: A total of 445 patients with head and neck and/or thoracic-abdominal or pelvic paragangliomas were recruited over 5 yr in 20 referral centers. In addition to classical direct sequencing of the SDHB, SDHC, and SDHD genes, two methods for detecting large genomic deletions or duplications were used, quantitative multiplex PCR of short fluorescent fragments (QMPSF) and multiplex ligation-dependent probe amplification (MLPA). RESULTS: A large variety of SDH germline mutations were found by direct sequencing in 220 patients and by QMPSF and MLPA in 22 patients (9.1%): 130 in SDHD, 96 in SDHB, and 16 in SDHC. Mutation carriers were younger and more frequently had multiple or malignant paraganglioma than patients without mutations. A head and neck paraganglioma was present in 97.7% of the SDHD and 87.5% of the SDHC mutation carriers, but in only 42.7% of the SDHB carriers. A thoracic-abdominal or pelvic location was present in 63.5% of the SDHB, 16.1% of the SDHD, and in 12.5% of the SDHC mutation carriers. Multiple paragangliomas were diagnosed in 66.9% of the SDHD mutation carriers. A malignant paraganglioma was documented in 37.5% of the SDHB, 3.1% of the SDHD, and none of the SDHC mutation carriers. CONCLUSIONS: SDH genetic testing, including tests for large genomic deletions, is indicated in all patients with head and neck and/or thoracic-abdominal or pelvic paraganglioma and can be targeted according to clinical criteria.

Usefulness of adrenal scintigraphy in the follow-up of adrenocortical incidentalomas: a prospective multicenter study.

OBJECTIVES: Prognostic factors for progression of benign adrenocortical adenomas (AI) remain poorly known. We assessed the usefulness of (131)I-6-beta-iodomethylnorcholesterol scintigraphy (IMS) to predict the occurrence of adrenal hyperfunction or mass enlargement. DESIGN: Fifty-one consecutive inpatients with unilateral AI and normal 24-h urinary free cortisol (UFC) were enrolled in a multicenter observational prospective study to investigate the relationship between the scintigraphic pattern and the progression of biological abnormalities of the hypothalamo-pituitary-adrenal axis or tumor size. RESULTS: Biochemically defined 'subclinical' Cushing's syndrome (SCS) was found at baseline in 47% of patients. Unilateral uptake (UU) was significantly associated with SCS (P<0.05). During the follow-up (4.3+/-1.6-year): 53% of patients showed unchanged hormonal evaluation, 29% displayed intermittent SCS and 18% showed definitive hormonal progression of SCS but without overt biochemical hypercortisolism. UU was associated with persistence of SCS and hormonal progression (P<0.01). In multivariate analysis, UU and impaired 1 mg dexamethasone suppression were independently associated with hormonal progression. Three patients with UU developed clinical CS despite persistently normal UFC. Tumor size increased in 10% patients and was not associated with any scintigraphic pattern. CONCLUSION: Evolution of SCS toward overt biochemical CS in patients with AI is a rare event during a 4-year follow-up. UU is predictive for the occurrence of SCS, its persistence and progression within the spectrum of SCS. Further studies aiming to establish the clinical consequences of SCS are needed to recommend IMS as a complementary evaluation in patients with AI and biochemical SCS.

Adiponectin increases insulin-like growth factor I-induced progesterone and estradiol secretion in human granulosa cells.

OBJECTIVE: To identify adiponectin and its receptors (AdipoR1 and AdipoR2) in human granulosa cells (GC) and to study the effects of recombinant human adiponectin on P and E(2) secretion from these cells. DESIGN: The effects of recombinant human adiponectin on the secretion of P and E(2) by cultured human GCs were investigated. SETTING: Academic institutions. PATIENT(S): Seventeen infertile and healthy women undergoing IVF. INTERVENTION(S): Primary human GC cultures stimulated with human recombinant adiponectin (5 microg/mL). MAIN OUTCOME MEASURE(S): Determination of messenger RNA (mRNA) and protein expression of adiponectin and its receptors AdipoR1 and AdipoR2 in fresh human GCs by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblot, respectively. Measurement of P and E(2) levels in the conditioned media by RIA and determination of cell proliferation by tritied thymidine incorporation. RESULT(S): Human GCs express adiponectin receptors AdipoR1 and AdipoR2 but not adiponectin. In primary human GCs, adiponectin increases P and E(2) secretion in response to insulin-like growth factor I (IGF-I). This was associated with an increase in the p450 aromatase protein level but not those of p450scc, 3 beta HSD, or StAR. Adiponectin treatment does not affect IGF-1-induced cell proliferation and basal steroidogenesis (no IGF-1 or FSH stimulation). Adiponectin rapidly stimulates MAPK ERK1/2 and p38 phosphorylation in primary human GCs. CONCLUSION(S): Adiponectin receptors AdipoR1 and AdipoR2, but not adiponectin, are present in human GCs. Adiponectin increases IGF-1-induced P and E(2) secretion in primary human GCs.

Kallmann's syndrome: a comparison of the reproductive phenotypes in men carrying KAL1 and FGFR1/KAL2 mutations.

CONTEXT: Kallmann's syndrome (KS) is a genetically heterogeneous disorder consisting of congenital hypogonadotropic hypogonadism (CHH) with anosmia or hyposmia. OBJECTIVE: Our objective was to compare the reproductive phenotypes of men harboring KAL1 and FGFR1/KAL2 mutations. DESIGN AND PATIENTS: We studied the endocrine features reflecting gonadotropic-testicular axis function in 39 men; 21 had mutations in KAL1 and 18 in FGFR1/KAL2, but none had additional mutations in PROK-2 or PROKR-2 genes. RESULTS: Puberty failed to occur in the patients with KAL1 mutations, all of whom had complete CHH. Three patients with FGFR1/KAL2 mutations had normal puberty, were eugonadal, and had normal testosterone and gonadotropin levels. Cryptorchidism was more frequent (14 of 21 vs. 3 of 15; P<00.1) and testicular volume (2.4+/-1.1 vs. 5.4+/-2.4 ml; P<0.001) was smaller in CHH subjects with KAL1 mutations than in subjects with FGFR1/KAL2 mutations. The mean basal plasma FSH level (0.72+/-0.47 vs. 1.48+/-0.62 IU/liter; P<0.05), serum inhibin B level (19.3+/-10.6 vs. 39.5+/-19.3 pg/ml; P<0.005), basal LH plasma level (0.57+/-0.54 vs. 1.0+/-0.6 IU/liter; P<0.01), and GnRH-stimulated LH plasma level (1.2+/-1.0 vs. 4.1+/-3.5 IU/liter; P<0.01) were significantly lower in the subjects with KAL1 mutations. LH pulsatility was studied in 13 CHH subjects with KAL1 mutations and seven subjects with FGFR1/KAL2 mutations; LH secretion was nonpulsatile in all the subjects, but mean LH levels were lower in those with KAL1 mutations. CONCLUSION: KAL1 mutations result in a more severe reproductive phenotype than FGFR1/KAL2 mutations. The latter are associated with a broader spectrum of pubertal development and with less severe impairment of gonadotropin secretion.

Expression of sex steroid hormone receptors in C cell hyperplasia and medullary thyroid carcinoma.

Previous studies have shown that C cells are twice as numerous in male than in female thyroids and that C cell hyperplasia (CCH) is much more frequent in men. These findings suggest regulation involving sex steroid hormones through the expression of sex steroid hormone receptors on C cells. To investigate this hypothesis, we performed an immunohistochemical study of estrogen receptors alpha (ER alpha) and beta (ER beta), progesterone receptors (PR), and androgen receptors (AR) on specimens from a series of 40 patients operated on for a medullary thyroid carcinoma (MTC; n=28; female 18, male 10) and/or CCH (n=19; female 6, male 13). ER beta was the only receptor to be consistently expressed in CCH (100%) and MTC (96.5%), whereas ER alpha was never expressed. PR and AR were rarely expressed in MTC (7 and 14%, respectively). AR was expressed in half the CCH cases (53%), with a trend to male predominance (61% in men vs 33% in women). Our study is the first to describe ER beta expression in CCH. In addition, our findings suggest that CCH, and possibly MTC, might be influenced by sex steroid hormones, namely, estrogens and androgens, through the expression of ER beta and AR on C cells.

Aryl hydrocarbon receptor-interacting protein gene mutations in familial isolated pituitary adenomas: analysis in 73 families.

CONTEXT: An association between germline aryl hydrocarbon receptor-interacting protein (AIP) gene mutations and pituitary adenomas was recently shown. OBJECTIVE: The objective of the study was to assess the frequency of AIP gene mutations in a large cohort of patients with familial isolated pituitary adenoma (FIPA). DESIGN: This was a multicenter, international, collaborative study. SETTING: The study was conducted in 34 university endocrinology and genetics departments in nine countries. PATIENTS: Affected members from each FIPA family were studied. Relatives of patients with AIP mutations underwent AIP sequence analysis. MAIN OUTCOME MEASURES: Presence/absence and description of AIP gene mutations were the main outcome measures. INTERVENTION: There was no intervention. RESULTS: Seventy-three FIPA families were identified, with 156 patients with pituitary adenomas; the FIPA cohort was evenly divided between families with homogeneous and heterogeneous tumor expression. Eleven FIPA families had 10 germline AIP mutations. Nine mutations, R16H, G47_R54del, Q142X, E174frameshift, Q217X, Q239X, K241E, R271W, and Q285frameshift, have not been described previously. Tumors were significantly larger (P = 0.0005) and diagnosed at a younger age (P = 0.0006) in AIP mutation-positive vs. mutation-negative subjects. Somatotropinomas predominated among FIPA families with AIP mutations, but mixed GH/prolactin-secreting tumors, prolactinomas, and nonsecreting adenomas were also noted. Approximately 85% of the FIPA cohort and 50% of those with familial somatotropinomas were negative for AIP mutations. CONCLUSIONS: AIP mutations, of which nine new mutations have been described here, occur in approximately 15% of FIPA families. Although pituitary tumors occurring in association with AIP mutations are predominantly somatotropinomas, other tumor types are also seen. Further study of the impact of AIP mutations on protein expression and activity is necessary to elucidate their role in pituitary tumorigenesis in FIPA.

A novel, C-terminal dominant negative mutation of the GR causes familial glucocorticoid resistance through abnormal interactions with p160 steroid receptor coactivators.

Primary cortisol resistance is a rare, inherited or sporadic form of generalized end-organ insensitivity to glucocorticoids. Here, we report a kindred in which affected members had a heterozygous T to G base substitution at nucleotide 2373 of exon 9alpha of the GR gene, causing substitution of Ile by Met at position 747. This mutation was located close to helix 12, at the C terminus of the ligand-binding domain, which has a pivotal role in the formation of activation function (AF)-2, a subdomain that interacts with p160 coactivators. The affinity of the mutant GR for dexamethasone was decreased by about 2-fold, and its transcriptional activity on the glucocorticoid-responsive mouse mammary tumor virus promoter was compromised by 20- to 30-fold. In addition, the mutant GR functioned as a dominant negative inhibitor of wild-type receptor-induced transactivation. The mutant GR through its intact AF-1 domain bound to a p160 coactivator, but failed to do so through its AF-2 domain. Overexpression of a p160 coactivator restored the transcriptional activity and reversed the negative transdominant activity of the mutant GR. Interestingly, green fluorescent protein (GFP)-fused GRalphaI747M had a slight delay in its translocation from the cytoplasm into the nucleus and formed coarser nuclear speckles than GFP-fused wild-type GRalpha. Similarly, a GFP-fused p160 coactivator had a distinctly different distribution in the nucleus in the presence of mutant vs. wild-type receptor, presenting also as coarser speckling. We conclude that the mutation at amino acid 747 of the GR causes familial, autosomal dominant glucocorticoid resistance by decreasing ligand binding affinity and transcriptional activity, and by exerting a negative transdominant effect on the wild-type receptor. The mutant receptor has an ineffective AF-2 domain, which leads to an abnormal interaction with p160 coactivators and a distinct nuclear distribution of both.