Deletion of CPEB1 Gene: A Rare but Recurrent Cause of Premature Ovarian Insufficiency

CONTEXT

Premature ovarian insufficiency (POI) may be secondary to chemotherapy, radiotherapy, or environmental factors. Genetic causes are identified in 20-25% of cases, but most POI cases remain idiopathic.

OBJECTIVE

This study aimed to identify new genes involved in POI and to characterize the implication of CPEB1 gene in POI.

DESIGN AND SETTING

This was a case report and cohort study replicate conducted in academic medical centers.

PATIENTS AND METHODS

A deletion including CPEB1 gene was first identified in a patient with primary amenorrhea. Secondly, 191 sporadic POI cases and 68 familial POI cases were included. For each patient, karyotype was normal and FMR1 premutation was excluded. Search for CPEB1 deletions was performed by quantitative multiplex PCR of short fluorescent fragments or DNA microarray analysis. Gene sequencing of CPEB1 was performed for 95 patients.

RESULTS

We identified three patients carrying a microdeletion in band 15q25.2. The proximal breakpoint, for the three patients, falls within a low-copy repeat region disrupting the CPEB1 gene, which represents a strong candidate gene for POI as it is known to be implicated in oocyte meiosis. No mutation was identified by sequencing CPEB1 gene. Therefore, heterozygous deletion of CPEB1 gene leading to haploinsufficiency could be responsible for POI in humans.

CONCLUSION

Microdeletions of CPEB1 were identified in 1.3% of patients with POI, whereas no mutation was identified. This microdeletion is rare but recurrent as it is mediated by nonallelic homologous recombination due to the existence of low-copy repeats in the region. This result demonstrates the importance of DNA microarray analysis in etiological evaluation and counseling of patients with POI.

Unraveling the intrafamilial correlations and heritability of tumor types in MEN1: a Groupe d'étude des Tumeurs Endocrines study

BACKGROUND

MEN1, which is secondary to the mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Most studies demonstrated the absence of direct genotype-phenotype correlations. The existence of a higher risk of death in the Groupe d'étude des Tumeurs Endocrines-cohort associated with a mutation in the JunD interacting domain suggests heterogeneity across families in disease expressivity. This study aims to assess the existence of modifying genetic factors by estimating the intrafamilial correlations and heritability of the six main tumor types in MEN1.

METHODS

The study included 797 patients from 265 kindred and studied seven phenotypic criteria: parathyroid and pancreatic neuroendocrine tumors (NETs) and pituitary, adrenal, bronchial, and thymic (thNET) tumors and the presence of metastasis. Intrafamilial correlations and heritability estimates were calculated from family tree data using specific validated statistical analysis software.

RESULTS

Intrafamilial correlations were significant and decreased along parental degrees distance for pituitary, adrenal and thNETs. The heritability of these three tumor types was consistently strong and significant with 64% (s.e.m.=0.13; P<0.001) for pituitary tumor, 65% (s.e.m.=0.21; P<0.001) for adrenal tumors, and 97% (s.e.m.=0.41; P=0.006) for thNETs.

CONCLUSION

The present study shows the existence of modifying genetic factors for thymus, adrenal, and pituitary MEN1 tumor types. The identification of at-risk subgroups of individuals within cohorts is the first step toward personalization of care. Next generation sequencing on this subset of tumors will help identify the molecular basis of MEN1 variable genetic expressivity.

[Cushing syndrome and pregnancy: a propos of a malignant adrenocortical carcinoma]

Cushing's syndrome is a rare condition in the general population (1/1000000) and is even less common during pregnancy. We report the case of a patient cared at 27 weeks of gestation (wg) for hypertension and electolyte disturbances. Cushing's syndrome was confirmed by salivary cortisol and ACTH assessment. RMN revealed a 9 cm left adrenal tumor. Severe hypertension and electolyte disturbances on the one hand, and diagnostic uncertainty on the other hand, imposed adrenalectomy at 29 wg. Twelve days later, fetal distress led to a caesarian section and birth of a well being male baby.

45,X/46,XX mosaicism below 30% of aneuploidy: clinical implications in adult women from a reproductive medicine unit

OBJECTIVE

Turner's syndrome (TS) is well known, but prognosis for 45,X/46,XX mosaicism below 30% of aneuploidy has not been established. We evaluated differences in clinical features and biological parameters between patients with numerical sex chromosome mosaicism diagnosed incidentally and control women.

DESIGN

Retrospective observational study of clinical features and biological parameters.

METHODS

Standard endocrinological and gynecological examination was done and early-follicular-phase blood values were collected from the medical records of women aged 21-43, who were referred to our ward from 1996 to 2006 because of infertility and were karyotyped. Seventy-one women with sex chromosome mosaicism (45,X/46,XX) ranging from 4 to 28% were assigned a chromosomally normal woman (46,XX) matched according to age (n=71).

RESULTS

In group 45,X/46,XX, 8% or more of aneuploidy accounted for a smaller height compared to controls (P=0.01). Body mass index was increased from 6% of aneuploidy (P=0.02) and was positively correlated to the percentage of 45,X cells (P=0.0001); menarche occurred earlier from 10% of aneuploidy (P=0.01) and was inversely correlated to the percentage of 45,X cells (P=0.045). No difference was found between the groups for FSH, LH, estradiol, inhibin B, and TSH values. Spontaneous abortions were more frequent in case of mosaicism (P=0.01), and recurrence was positively correlated to the percentage of aneuploidy (P=0.008).

CONCLUSION

Sex chromosome mosaicism is responsible for clinical changes from 6% of aneuploidy, corresponding to the main phenotypical features of TS.

Hypophysitis associated with a ruptured Rathke's cleft cyst in a woman, during pregnancy

We report the case of a 29-yr-old woman who first presented an aseptic meningitis at the beginning of a pregnancy. She was admitted one month later with headaches and vomiting. Panhypopituitarism with diabetes insipidus was diagnosed. Magnetic resonance imaging (MRI) data suggested the existence of lymphocytic infundibulohypophysitis, with inflammation of the suprasellar area. No new symptoms were noticed until 6 months later when this patient pointed out troubles of the visual field, due to a compression of the optic chiasma. Three boluses of 1 g methylprednisolone were prescribed, with no effects. After delivery, the defects of the visual field increased. A neurosurgical intervention was decided. Diagnosis of Rathke's cleft cyst (RCC) was made. We concluded that this patient presented a rupture of a RCC, which occurred at the beginning of pregnancy, associated later with panhypopituitarism with diabetes insipidus, due to a probable hypophysitis. The end of the pregnancy was marked by consequences of an increased volume of the RCC. To our knowledge, this case is the first described during pregnancy.

[Oral manifestations of endocrine dysfunction]

Oral manifestations of endocrine dysfunction often may be observed initially by the dentist. Objective manifestations, such as ophtalmos in hyperthyroidism, signs of hypersecretion of GH in acromegaly, are easily recognized. Dentists should have some knowledge of many other diseases in this category that occasionally come in our attention. The present article will discuss the effects of over and under-secretion of each endocrine gland separately, showing its influence on the development and maintenance of the health of the teeth and supporting structures. Diabetes mellitus is the most common endocrinological disease, with an incidence of 3%. Periodontitis risk is three time greater in diabetic patients than in general population and it may worsen the diabetes evolution. Periodontitis in diabetic patients needs an rapid diagnosis and treatment. We also presents the oral aspects of thyroid, parathyroid, suprarenalian, growth hormone and female hormones pathology. The incidence of these troubles is less important, but oral manifestations may reveal an endocrine disfunction.

Self-monitoring of blood glucose significantly improves metabolic control in patients with type 2 diabetes mellitus: the Auto-Surveillance Intervention Active (ASIA) study

OBJECTIVE

Self monitoring of blood glucose (SMBG) in type 2 diabetes is a topic of current interest (imbalance between increased health-care costs and improvement in compliance with treatment and diet). An open label randomized prospective study was designed to compare changes in metabolic control over 6 months in patients managed with usual recommendations alone (conventional assessment group) or combined with SMBG.

RESEARCH DESIGN AND METHODS

Patients not treated with insulin or previously self monitored, 40 to 75 years of age, with a diagnosis of type 2 diabetes > 1 year and standardized HbA(1c) level > =7.5 and< =11% were randomized to either a control group or SMBG group. They were followed up every 6 weeks over 24 weeks. Patients in the SMBG group were given the same device (Ascensia Esprit Discmeter, Bayer) and were required to perform at least 6 capillary assays a week (3 different days of the week, including weekend). Management of patients was standardized, including drugs, diet and physical activity. The primary efficacy criterion was change in HbA(1c) level in Intent To Treat (ITT) patients. Assays were performed at baseline, at 3 and 6 months using the calibrated DCA 2000(R) device (Bayer).

RESULTS

Two hundred sixty five general practitioners randomized 988 patients (ITT Population), but 689 patients were evaluable for the primary criterion. At the endpoint, HbA(1c) was lower in the SMBG group (8.1 +/- 1.6%) than in the conventional treatment group (8.4 +/- 1.4%, P=0.012). The change in HbA(1c) levels between baseline and endpoint was classified into two classes: improvement if a change > 0.5% occurred, stability or worsening in case of a change< =0.5%; 57.1% of patients in the SMBG group vs 46.8% in the control group had an improvement in HbA(1c) level (P=0.007) after 3 months. A steady state was reached during the last 3 months. A multivariate logistic regression analysis was performed and identified factors predictive of improvement in HbA(1c) levels: HbA(1c) at baseline: odd ratio (OR)=1.749 (P<0.001), SMBG group (reference value: SMBG group): OR=0.665 (P=0.015), duration of diabetes: OR=0.953 (P=0.001) and BMI: OR=0.962 (P=0.039).

CONCLUSIONS

This study is the first multicenter, controlled, prospective trial conducted on a large number of patients demonstrating that SMBG was statistically associated with a better quality of metabolic control than usual traditional recommendations alone in type 2 diabetes.

[Inappropriate secretion of antidiuretic hormone and diabetes insipidus after surgery for pituitary adenoma]

The purpose of our study was to evaluate the incidence and risk factors of SIADH (syndrome of inappropriate antidiuretic hormone) and diabetes insipidus after pituitary adenoma surgery in patients and report follow-up data collected in our department of endocrinology. This retrospective study included 78 patients seen in the last 5 years. Possible risk factors of SIADH and diabetes insipidus were studies: patient age and gender, type of secretion, tumor volume, surgical approach, presence of postoperative pituitary failure. The incidence of SIADH and diabetes insipidus were similar: 12.8%. We did not find any risk factor for SIADH associated with postoperative anterior pituitary failure. This study illustrates the importance of postoperative follow-up after pituitary adenoma surgery.

[Primary hyperaldosteronism and adenoma of the adrenal cortex. Suppression of aldosterone with dexamethasone]

The aim of the study was to evaluate dexamethazone test in a patient with primary aldosteronism caused by an adrenocortical adenoma. We observed a 50% decrease of plasma aldosterone as in glucocorticoid suppressible aldosteronism (GSA) but absolute value of aldosterone remained higher than 40 pg/ml. Basal plasma and urinary values of 18 OXO and 18 OH cortisol were not significantly elevated as in GSA. Inversely, the evaluation of 11 beta-hydroxylase activity of mineralocorticoids was in favor of a benign adrenal tumor.

Ocular naevus and melanoma in acromegaly

Acromegaly favours the development of extrapituitary neoplasms presumably promoted through increased GH and IGF-I levels. We describe here two patients which acromegaly and benign and malignant melanocytic tumours of the eye choroid. The first patient had a 15 year history of progressive acromegaly despite trans-sphenoidal surgery, radiation and bromocriptine therapy when she presented with melanoma of the eye and a contralateral benign melanocytic tumour. The second patient was referred with typical acromegaly. The initial fundal examination revealed a right sided benign melanocytic tumour of the choroid. Subsequent follow up of the naevi has not shown any change in the tumours after one and three years respectively. The occurrence of melanoma has not been reported in acromegaly. Increased growth of benign naevi might be expected as GH and IGF-I receptors have been described on melanocytes. As naevi may degenerate into melanomas in normal subjects and radiation therapy could trigger their transformation, we suggest that prior to irradiation, acromegalic subjects should undergo a careful ocular examination in order to assess the presence of ocular naevi.

[Evolution of levels of free thyroxine and thyrotropin in treated Cushing disease]

OBJECTIVE

Determine the frequency and changes in thyroid hormones in Cushing's disease.

METHODS

Free thyroxin and thyrotropin levels were measured in 11 patients (age range 17 to 60 years) with Cushing's disease both before and after resection of the pituitary adenoma.

RESULTS

Free thyroxin levels were low (8.3 to 11.7 pmol/l) in 7 patients. These patients had no clinical manifestations of hypothyroidism. In 4 patients, cure of the pituitary adenoma led to normalization of the thyroid hormones 10 days after operation (13 to 55 pmol/l); in the other cases surgical cure was unsuccessful and thyroxin levels remained low. Cortisol levels were finally normalized in these patients after irradiation of the pituitary, a second pituitary operation, or bilateral resection of the adrenal glands in 2 patients. Normal thyroxin levels were thus achieved. There was no correlation between serum cortisol and free thyroxin.

CONCLUSION

Thyroid hormones should be assayed regularly in patients with Cushing's disease as a supplementary control of treatment effectiveness.

Longitudinal study of maternal plasma bioavailable testosterone and androstanediol glucuronide levels during pregnancy

OBJECTIVE

The aim of this study to evaluate during normal pregnancy plasma bioavailable testosterone and androstanediol glucuronide levels.

MEASUREMENTS

Bioavailable testosterone, androstanediol glucuronide and SHBG levels were evaluated every 4 weeks from week 6 to week 38 in 10 normal pregnant women. We also measured plasma oestradiol, oestriol, delta 4-androstenedione, 17-hydroxyprogesterone, progesterone and testosterone.

RESULTS

The mean bioavailable testosterone levels were within the range of non-pregnant women but with an increasing trend until delivery. Androstanediol glucuronide had increased at weeks 6 and 8, decreased at week 14, remained low at week 30, and increased again at week 34. SHBG was significantly correlated with testosterone, oestradiol and oestriol. No correlation could be established between androstanediol glucuronide and any other parameter.

DISCUSSION

Bioavailable testosterone (non-SHBG bound testosterone) represents the sum of free testosterone plus albumin bound testosterone. The increase in testosterone concentrations with decreased albumin levels during pregnancy, could suggest reduced metabolic clearance of testosterone throughout pregnancy. No correlation was established between the decrease in androstanediol glucuronide and increase in progesterone, suggesting that the decrease in androstanediol glucuronide is not a consequence of the inhibitory effect of progesterone on 5 alpha-reductase activity.

Nature of cytochromes P450 involved in the 2-/4-hydroxylations of estradiol in human liver microsomes

Kinetics of the 2- and 4-hydroxylations of estradiol (E2) by human liver microsomal samples were studied to determine the major P450 isoform involved in these endogenous reactions. Thirty human liver microsomal samples were analysed. Metabolism of 25 microM [14C]E2 produced 2-hydroxy and 4-hydroxy derivatives with a ratio of 3.2 +/- 1.5 and a great inter-individual variation. Kinetic analysis of the 2- and 4-hydroxylations of E2 exhibited a curvilinear double reciprocal plot with an apparent Km of 15 microM. Further experiments demonstrated that alpha-naphthoflavone, testosterone and progesterone increased the 2-hydroxylation activity, suggesting the involvement of a substrate activation mechanism. These two hydroxylations of E2 were shown to be catalysed by cytochrome P450 with an apparent dissociation constant Ks of 0.8 microM. These 2- and 4-hydroxylations inter-correlated significantly (r = 0.93; N = 30). The 2-hydroxylation of E2 correlated with four monooxygenase activities known to be supported by P450 3A4/3A5, namely nifedipine oxidation (r = 0.78; N = 29); erythromycin N-demethylation (r = 0.69; N = 27), testosterone 6 beta-hydroxylation (r = 0.66; N = 25) and tamoxifen N-demethylation (r = 0.64; N = 29). On the other hand, E2-hydroxylations did not correlate with activities supported by P450 1A2 and P450 2E1. Furthermore, drugs as cyclosporin, diltiazem, triacetyl-oleandomycin and 17 alpha-ethynylestradiol inhibited more than 90% of the E2-hydroxylations at concentrations < 250 microM, while weak inhibition was shown with 500 microM cimetidine and no significant inhibition with caffeine, phenacetin and omeprazole. Finally, 2- and 4-hydroxylations of E2 correlated significantly with the content of P450 3A4/3A5 immunodetected by a monoclonal antibody anti-human P450-nifedipine (r = 0.84; N = 28). E2-hydroxylation activities were inhibited by more than 80% with polyclonal anti-human anti-P450-nifedipine. Preincubation of human liver microsomes with 100 microM gestodene (a suicide substrate of P450 3A4) inactivated this P450 isoform and accordingly allowed evaluation of the contribution of other P450 isoforms to the E2 metabolism to about 21% (+/- 17%, N = 29). All these results taken together suggest that P450 3A4/3A5 are the major forms involved in the formation of catecholestrogens in the human liver microsomes.

Oestrogen secreting Leydig cell tumour and GnRH agonist in-vivo and in-vitro studies

OBJECTIVE

The purposes of our study concerning two patients with oestrogen secreting Leydig cell tumour were to determine whether endogenous LH levels are involved in testicular tumour steroidogenesis and whether aromatase activity of oestrogen secreting Leydig cell tumours is directly or indirectly dependent on LH levels.

MEASUREMENTS

E2 and T were evaluated after hCG injection (5000 IU) during 96 hours. Bio and immuno LH, T, E2, were determined at the basal state and after administration of D-Trp-6-GnRH agonist (3.75 mg) every 3 weeks. The abnormal testis was removed after the third injection and testicular venous blood was collected during the operation. Testicular tumour was incubated with 4-14C-T.

RESULTS

Oestradiol (E2) response to hCG injection (5000 IU) was prolonged and exaggerated while that of testosterone (T) was similar to that of the controls. The aromatase index (E2/T) remained elevated even 96 hours after hCG. Intramuscular injection of the GnRH agonist, D-Trp-6-GnRH (3.75 mg) resulted in a reduction of immunoreactive and bioactive LH. T was decreased to about 10% of baseline levels and E2 fell from 240 to 36 pmol/l. In the blood of the spermatic veins collected in the course of surgery, E2 levels were found to be lower in comparison with the controls. E2 was found to be twofold higher in the spermatic vein draining the tumoral side than in that of the contralateral testis. Incubation of the testicular tumours with 4-14C-T, displayed a reduced aromatase activity (conversion of T to E2: 0.3 and 0.1% in patients 1 and 2 respectively).

CONCLUSIONS

The kinetics of E2 response to hCG administration would suggest a modification of the regulation of the aromatase activity in this type of oestrogen secreting tumour. A certain endogenous LH level may be necessary to supply a sufficient quantity of T substrate, and to maintain aromatase activity of such Leydig cell tumours secreting oestrogens. These tumours seem to be responsive to endogenous LH levels.

[Serologically detected HY antigen and its regulation]

The serologically detected, male predominant s HY Ag is a surface glycoprotein. The structural gene would be located on the 6th chromosome and regulated by gonosomal genes. The presence of testes (or testicular remenants) is linked to the s HY antigen expression in most abnormalities of sexual differentiation. However, the basal s HY Ag value is sometimes increased in the absence of any testicular tissue, as in virilized females (21-hydroxylase deficiency, idiopathic or ovarian hirsutism). Homogametic sex s HY Ag may increase to heterogametic sex values under the action of androgens in mammals and that of oestrogens in birds.

[Long-term effects of treatment with SMS 201-995 on sleep apnea syndrome associated with acromegaly]

A 60-year-old woman with acromegaly associated with sleep apnea was treated with the somatostatin analogue SMS 201-995 (Sandoz) for several months. Growth hormone levels were normalized and a rapid improvement in sleep apnea was controlled with polygraphic nocturnal monitoring. Hypophysectomy seems to have variable effects on sleep apnea in acromegaly. The origin of obstructive apnea in acromegaly is therefore unclear.

[Adrenoleukodystrophy in the child and adrenomyeloneuropathy. Study of 2 families]

Ten subjects from 2 families with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN), hereditary X-linked diseases, were systematically explored. We performed endocrinological, biochemical assays and neurophysiological tests; the latter consisted of nerve conductions (CNV), Hoffmann's reflex and multimodal evoked potentials: visual (flash and pattern, VEP), brainstem auditory (BAEP) and somesthetic (SEP) using median nerve stimulation at the wrist. We only considered values above 2 SD. The purpose of our study was to determine the correlation between neurophysiological and endocrinological perturbations and the presence of pathological traits. Our results suggest that the correlation is high in diseased male patients, lower for the ALD carriers (BAEP, SEP and CNV were more frequently abnormal) and very low for the AMN carriers. Only the biochemical assays appeared to have any value for the characterization of female carriers of ALD and AMN.

[Pregnancy: a way of recovering from prolactin-secreting adenoma? 18 cases]

Fifteen patients with prolactin-secreting pituitary adenoma completed a total of 18 pregnancies. Changes in blood prolactin levels and computerized tomographic images of the pituitary gland were studied. No increase in size of the adenoma was observed, and in 2 cases the tumour was found to be necrotic in the post-partum period. In all patients the prolactinaemia significantly decreased immediately after delivery. Thus, by inducing partial necrosis of the adenoma pregnancy may result in post-partum reduction of blood prolactin levels.

Leydig cell tumor with gynecomastia: further studies--the recovery after unilateral orchidectomy

The recovery of exocrine and endocrine testicular function was studied in six patients orchidectomized for an estrogen-producing Leydig cell tumor. Gynecomastia disappeared in four patients. The contralateral testis, whose volume was reduced, returned to normal size after 30 days. Sperm density returned to normal in only one of the four patients in whom the preoperative sperm count was reduced. One day after unilateral orchidectomy, plasma estradiol decreased to normal and testosterone (T) fell about 50%. On the 10th postoperative day, plasma T [5.60 +/- 1.20 ng/ml (SD)] was normal. On day 120, T was higher than on day 10 (6.83 +/- 1.20 ng/ml). There was no significant increase of T after a single injection of hCG (5000 IU) on day 10, and the T response was similar to that of normal men on day 120. Plasma FSH and LH were increased on the 10th postoperative day; they then decreased between 60 and 120 days after the operation but were still above the normal values on day 120. The FSH/LH ratio, which was 0.43 +/- 0.17 preoperatively returned to normal (1.60 +/- 0.25) 10 days postoperatively. In conclusion, after hemicastration for an estrogen-secreting tumor, testicular hormonal secretion returns to normal within 120 days but spermatogenesis may still be impaired at this time.