Paolo Beck-Peccoz

Hypergonadotropic Ovarian Failure Associated with an Inherited Mutation of Human Bone Morphogenetic Protein-15 (BMP15) Gene

Hypergonadotropic ovarian failure is a common cause of female infertility. It is a heterogeneous disorder that, in the most severe forms, is a result of ovarian dysgenesis (OD). Most OD cases are associated with major X-chromosome abnormalities, but the pathogenesis of this disorder is still largely undefined in patients with a normal karyotype. Animal models showed the important role in female reproduction played by the product of a gene located at Xp11.2 in humans (BMP15). BMP15 is an oocyte-specific growth/differentiation factor that stimulates folliculogenesis and granulosa cell (GC) growth. We report two sisters with a normal karyotype who are affected with hypergonadotropic ovarian failure due to OD. The familial presentation suggested a genetic origin, and candidate genes were screened for mutations. A heterozygous nonconservative substitution in the pro region of BMP15 (Y235C) was identified in both sisters but not in 210 control alleles. This mutation was inherited from the father. Mutant BMP15 appears to be processed abnormally, is associated with reduced GC growth, and antagonizes the stimulatory activity of wild-type protein on GC proliferation. In conclusion, the first natural mutation in human BMP15 is associated with familial OD, indicating that the action of BMP15 is required for the progression of human folliculogenesis. This condition represents an exceptional example of X-linked human disease exclusively affecting heterozygous females who inherited the genetic alteration from the unaffected father. BMP15 defects are involved in the pathogenesis of hypergonadotropic ovarian failure in humans.

Premature ovarian failure

Premature ovarian failure (POF) is a primary ovarian defect characterized by absent menarche (primary amenorrhea) or premature depletion of ovarian follicles before the age of 40 years (secondary amenorrhea). It is a heterogeneous disorder affecting approximately 1% of women <40 years, 1:10,000 women by age 20 and 1:1,000 women by age 30. The most severe forms present with absent pubertal development and primary amenorrhea (50% of these cases due to ovarian dysgenesis), whereas forms with post-pubertal onset are characterized by disappearance of menstrual cycles (secondary amenorrhea) associated with premature follicular depletion. As in the case of physiological menopause, POF presents by typical manifestations of climacterium: infertility associated with palpitations, heat intolerance, flushes, anxiety, depression, fatigue. POF is biochemically characterized by low levels of gonadal hormones (estrogens and inhibins) and high levels of gonadotropins (LH and FSH) (hypergonadotropic amenorrhea). Beyond infertility, hormone defects may cause severe neurological, metabolic or cardiovascular consequences and lead to the early onset of osteoporosis. Heterogeneity of POF is also reflected by the variety of possible causes, including autoimmunity, toxics, drugs, as well as genetic defects. POF has a strong genetic component. X chromosome abnormalities (e.g. Turner syndrome) represent the major cause of primary amenorrhea associated with ovarian dysgenesis. Despite the description of several candidate genes, the cause of POF remains undetermined in the vast majority of the cases. Management includes substitution of the hormone defect by estrogen/progestin preparations. The only solution presently available for the fertility defect in women with absent follicular reserve is ovum donation.

BRAF mutations in an Italian cohort of thyroid cancers

objective  Recently, a somatic point mutation of the BRAF gene (V599E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (about 25–70%) in different series from USA, Japan, Portugal and Ukraine.

Maternal and foetal resistin and adiponectin concentrations in normal and complicated pregnancies

Objective   The aim of this study was to evaluate how resistin and adiponectin (ApN) are involved in maternal energy metabolism and foetal growth.

A 7-year experience with low blood TSH cutoff levels for neonatal screening reveals an unsuspected frequency of congenital hypothyroidism (CH)

Context  The guidelines of the National Academy of Clinical Biochemistry advocated the use of low bloodspot TSH (b‐TSH) threshold for newborn screening of congenital hypothyroidism (CH). The impact generated by the application of this indication is largely unknown.

A role for helix 3 of the TRβ ligand-binding domain in coactivator recruitment identified by characterization of a third cluster of mutations in resistance to thyroid hormone

Resistance to thyroid hormone (RTH) has hitherto been associated with thyroid hormone β receptor (TRβ) mutations which cluster in two regions (αα 310–353 and αα 429–461) of the hormone‐binding domain and closely approximate the ligand‐binding cavity. Here, we describe a third cluster of RTH mutations extending from αα 234–282 which constitute a third boundary of the ligand pocket. One mutant, T277A, exhibits impaired transactivation which is disproportionate to its mildly reduced ligand affinity (Ka). T3‐dependent recruitment of coactivators (SRC‐1, ACTR) by mutant receptor–RXR heterodimers was reduced in comparison with wild‐type. Cotransfection of SRC‐1 restored transactivation by T277A. In the TRβ crystal structure this helix 3 residue is surface‐exposed and is in close proximity to residues L454 and E457 in helix 12 which are known to be critical for coactivator interaction, suggesting that they all constitute part of a receptor–coactivator interface. The transcriptional function of other mutants (A234T, R243W/Q, A268D, Δ276I, A279V, R282S) in this cluster correlated with their reduced Ka and they inhibited wild‐type TRβ action in a dominant negative manner. DNA binding, heterodimerization and corepressor recruitment were preserved in all mutants, signifying the importance of these attributes for dominant negative activity and correlating with the absence of natural mutations in regions bordering the third cluster which mediate these functions.

Beneficial Metabolic Effects of Prompt Surgical Treatment in Patients with an Adrenal Incidentaloma Causing Biochemical Hypercortisolism

CONTEXT In patients with adrenal incidentalomas, subclinical hypercortisolism (SH) is associated with an increased prevalence of the metabolic syndrome. The effect of surgical/conservative approach is debated. OBJECTIVE The objective of the study was to determine the effect of the surgical and conservative approaches on the metabolic syndrome in patients with adrenal incidentalomas. DESIGN This was a retrospective longitudinal study (18-48 months follow-up). SETTING The study was conducted on an in- and outpatient basis. PATIENTS One hundred eight patients with adrenal incidentalomas were studied for the presence of SH, which was diagnosed in the presence of more than two of the following: urinary free cortisol greater than 70 microg per 24 h (193 nmol per 24 h), cortisol after 1 mg dexamethasone suppression test greater than 3.0 microg/dl (83 nmol/liter), ACTH less than 10 pg/ml (2.2 pmol/liter). INTERVENTIONS Surgery was performed in 25 patients with SH (group TrSH+) and 30 without SH (group TrSH-), whereas the conservative approach was chosen by 16 patients with SH (group UntrSH+) and 37 without SH (group UntrSH-). MAIN OUTCOME MEASURES During the follow-up, the improvement/worsening of body weight, blood pressure, or glucose and cholesterol levels was defined in the presence of a greater than 5% weight decrease/increase and following the European Society of Cardiology or the Adult Treatment Panel III criteria, respectively. RESULTS In group TrSH+, weight, blood pressure, and glucose levels improved (32, 56, and 48%, respectively) more frequently than in group UntrSH+ (12.5%, P = 0.05; 0.0%, P < 0.0001; 0.0%, P = 0.001; and 0.0%, P = 0.0014, respectively). In group UntrSH+, blood pressure, glucose, and low-density lipoprotein levels worsened more frequently (50.0, 37.5, and 50.0%, respectively) than in group TrSH+ (0.0%, P < 0.0001; 0.0%, P = 0.001; and 20.0%, P = 0.05, respectively). CONCLUSIONS Regarding the various components of the metabolic syndrome, in patients with adrenal incidentalomas and SH, surgery is beneficial.

Pregnancy outcome after cabergoline treatment in early weeks of gestation

We collected information on 61 pregnancies in 50 women treated with cabergoline. These pregnancies resulted in 12 (19.7%) early terminations (five induced abortions, six spontaneous abortions, one hydatidiform mole) and 49 (80.3%) live births. In one case, malformations were suspected by a gynecologist based on ultrasound at 12 gestational weeks and the pregnancy was terminated; additional information was not available. There was one case of trisomy 18. The frequency of spontaneous and induced abortions and major congenital malformations was comparable with rates in the general population. The data did not indicate any potential adverse effect of the drug on pregnancy. The data from this study in combination with previous reports can exclude a congenital malformation risk greater than 10% associated with pregnancy exposure to cabergoline.

Pseudohypoparathyroidism and GNAS Epigenetic Defects: Clinical Evaluation of Albright Hereditary Osteodystrophy and Molecular Analysis in 40 Patients

CONTEXT The two main subtypes of pseudohypoparathyroidism (PHP), PHP-Ia and -Ib, are caused by mutations in GNAS exons 1-13 and methylation defects in the imprinted GNAS cluster, respectively. PHP-Ia patients show Albright hereditary osteodystrophy (AHO) and resistance toward PTH and additional hormones, whereas PHP-Ib patients do not have AHO, and hormone resistance appears to be limited to PTH and TSH. Recently, methylation defects have been detected in few patients with PHP and mild AHO, indicating a molecular overlap between the two forms. OBJECTIVES The aim of the study was to screen patients with clinically diagnosed PHP-Ia for methylation defects and to investigate the presence of correlations between the molecular findings and AHO severity. PATIENTS AND METHODS We investigated differential methylation of GNAS regions and STX16 microdeletions in genomic DNA from 40 patients with sporadic AHO and multihormone resistance, with no mutations in Gsalpha-coding GNAS exons. RESULTS Molecular analysis showed GNAS cluster imprinting defects in 24 of the 40 patients analyzed. No STX16 deletion was detected. The presence of imprinting defects was not associated with the severity of AHO or with specific AHO signs. CONCLUSIONS We report the largest series of the literature of patients with clinical AHO and multihormone resistance and no mutation in the Gsalpha gene. Our findings of frequent GNAS imprinting defects further confirm the existence of an overlap between molecular and clinical features of PHP-Ia and PHP-Ib and highlight the necessity of a new clinical classification of the disease that takes into account the recent knowledge on the molecular basis underlying these defects.

Bone Mineral Density, Prevalence of Vertebral Fractures, and Bone Quality in Patients with Adrenal Incidentalomas with and without Subclinical Hypercortisolism: An Italian Multicenter Study

CONTEXT In patients with adrenal incidentalomas and subclinical hypercortisolism (SH), the factors influencing bone and the prevalence of vertebral fractures are debated. Spinal deformity index (SDI), which reflects bone quality, has never been evaluated. OBJECTIVE The objective of the study was to investigate in these patients SDI and factors influencing the prevalence of fractures. DESIGN This was a retrospective, multicenter study. SETTING The study was conducted on an in- and outpatient basis. PATIENTS Patients included 287 adrenal incidentaloma patients (111 eugonadal males, 31 premenopausal, 145 postmenopausal females) and 194 controls (90 eugonadal males, 29 premenopausal, 75 postmenopausal females). MAIN OUTCOME MEASURE Bone mineral density (BMD) was measured by dual X-ray absorptiometry at lumbar spine and femoral neck. By radiograph each vertebra was assessed as intact (grade 0) or grade 1 (20-25%), 2 (25-40%), or 3 (>40%) deformity; SDI was calculated by summing the grade of deformity for each vertebra. SH was diagnosed in the presence of at least two of the following: urinary free cortisol greater than 70 microg per 24 h (193.1 nmol/liter), cortisol after 1-mg dexamethasone test greater than 3.0 microg/dl (>82.8 nmol/liter), ACTH less than 10 pg/ml (<2.2 pmol/liter). RESULTS BMD was significantly lower in SH+ than SH- patients and controls (lumbar spine -0.73 +/- 1.43, 0.17 +/- 1.33, 0.12 +/- 1.21, respectively; femoral neck -0.37 +/- 1.06, 0.07 +/- 1.09, 0.17 +/- 1.02). Patients with SH had higher fracture prevalence and SDI than those without SH and controls (70.6, 22.2, 21.8%, respectively, P < 0.0001; 0.31 +/- 0.68, 0.39 +/- 0.93, 1.35 +/- 1.27, respectively, P < 0.0001). Fractures and SDI were associated with SH (odds ratio 7.27, 95% confidence interval 3.94-13.41, P = 0.0001; beta = 0.352, t = 6.241, P = 0.0001, respectively) regardless of age, BMD, menopause, and gender. CONCLUSION SH is associated with low BMD, high fracture prevalence, and reduced bone quality as measured by SDI.