Mobile DNA in Endocrinology: LINE-1 Retrotransposon Causing Partial Androgen Insensitivity Syndrome.

CONTEXT: Androgen insensitivity syndrome (AIS) is the most common cause of disorders of sex development in 46,XY individuals. It is an X-linked condition usually caused by pathogenic allelic variants in the androgen receptor (AR) gene. The phenotype depends on the AR variant, ranging from severe undervirilization (complete AIS) to several degrees of external genitalia undervirilization. Although 90% of those with complete AIS will have AR mutations, this will only be true for 40% of those with partial AIS (PAIS). OBJECTIVE: To identify the genetic etiology of AIS in a large multigenerational family with the PAIS phenotype. PARTICIPANTS: Nine affected individuals with clinical and laboratory findings consistent with PAIS and a normal exonic AR sequencing. SETTINGS: Endocrine clinic and genetic institute from two academic referral centers. DESIGN: Analysis of whole exons of the AR gene, including splicing regions, was performed, followed by sequencing of the 5'untranslated region (UTR) of the AR gene. Detailed phenotyping was performed at the initial diagnosis and long-term follow-up, and circulating levels of steroid gonadal hormones were measured in all affected individuals. AR expression was measured using RT-PCR and cultured fibroblasts. RESULTS: All 46,XY family members with PAIS had inherited, in hemizygosity, a complex defect (∼1100 bp) in the 5'UTR region of the AR surrounded by a duplicated 18-bp sequence (target site duplication). This sequence is 99.7% similar to an active, long, interspersed element present on the X chromosome (AC002980; Xq22.2), which was inserted in the 5'UTR of the AR gene, severely reducing AR expression and leading to PAIS. CONCLUSION: The molecular diagnosis of PAIS remains challenging. The genomic effect of retrotransposon mobilization should be considered a possible molecular cause of AIS and other AR diseases.

Non-canonical dimerization of the androgen receptor and other nuclear receptors: implications for human disease.

Nuclear receptors are transcription factors that play critical roles in development, homeostasis and metabolism in all multicellular organisms. An important family of nuclear receptors comprises those members that respond to steroid hormones, and which is subdivided in turn into estrogen receptor (ER) isoforms α and ß (NR3A1 and A2, respectively), and a second subfamily of so-called oxosteroid receptors. The latter includes the androgen receptor (AR/NR3C4), the glucocorticoid receptor (GR/NR3C1), the mineralocorticoid receptor (MR/NR3C2) and the progesterone receptor (PR/NR3C3). Here we review recent advances in our understanding of the structure-and-function relationship of steroid nuclear receptors and discuss their implications for the etiology of human diseases. We focus in particular on the role played by AR dysregulation in both prostate cancer (PCa) and androgen insensitivity syndromes (AIS), but also discuss conditions linked to mutations of the GR gene as well as those in a non-steroidal receptor, the thyroid hormone receptor (TR). Finally, we explore how these recent results might be exploited for the development of novel and selective therapeutic strategies.

Oestrogen versus androgen in hormone-replacement therapy for complete androgen insensitivity syndrome: a multicentre, randomised, double-dummy, double-blind crossover trial.

BACKGROUND: Women with complete androgen insensitivity syndrome (CAIS) after gonadectomy have complained about reduced psychological wellbeing and sexual satisfaction. The aim of this study was to compare the effectiveness of hormone-replacement therapy with either androgen or oestrogen in women with 46,XY karyotype and CAIS after gonadectomy. METHODS: This national, multicentre, double-blind, randomised crossover trial was performed at three university medical centres and three specialised treatment institutions in Germany. Eligible participants were women aged 18-54 years with 46,XY karyotype, genetically diagnosed CAIS, and removed gonads. Participants were randomly assigned (14:12) by a central computer-based minimisation method to either oestradiol 1·5 mg/day for 6 months followed by crossover to testosterone 50 mg/day for 6 months (sequence A) or to testosterone 50 mg/day for 6 months followed by crossover to oestradiol 1·5 mg/day for 6 months (sequence B). Participants also received oestradiol or testosterone dummy to avoid identification of the active substance. All participants received oestradiol 1·5 mg/day during a 2 months' run-in phase. The primary outcome was mental health-related quality of life, as measured with the standardised German version of the SF-36 questionnaire. Secondary outcomes were psychological wellbeing, as measured with the Brief Symptom Inventory (BSI), sexual function, as measured with the Female Sexual Function Index (FSFI), and somatic effects, such as signs of virilisation and effects on metabolic blood values. The primary analysis included all patients who were available at least until visit 5, even if protocol violations occurred. The safety analysis included all patients who received at least oestradiol during the run-in phase. This trial is registered with the German Clinical Trials Register, number DRKS00003136, and with the European Clinical Trials Database, number 2010-021790-37. FINDINGS: We enrolled 26 patients into the study, with the first patient enrolled on Nov 7, 2011, and the last patient leaving the study on Jan 23, 2016. 14 patients were assigned to sequence A and 12 were assigned to sequence B. Ten participants were withdrawn from the study, two of whom attended at least five visits and so could be included in the primary analysis. Mental health-related quality of life did not differ between treatment groups (linear mixed model, p=0·794), nor did BSI scores for psychological wellbeing (global severity index, p=0·638; positive symptom distress index, p=0·378; positive symptom total, p=0·570). For the FSFI, testosterone was superior to oestradiol only in improving sexual desire (linear mixed model, p=0·018). No virilisation was observed, and gonadotrophin concentrations remained stable in both treatment groups. Oestradiol and testosterone concentrations changed substantially during the study in both treatment groups. 28 adverse events were reported for patients receiving oestradiol (23 grade 1 and five grade 2), and 38 adverse events were reported for patients receiving testosterone (34 grade 1, three grade 2, and one grade 3). One serious adverse event (fibrous mastopathy) and 20 adverse events (16 grade 1 and four grade 2) were reported during the run-in phase, and 12 adverse events during follow-up (nine grade 1 and three grade 2). INTERPRETATION: Testosterone was well tolerated and as safe as oestrogen for hormone-replacement therapy. Testosterone can be an alternative hormone substitution in CAIS, especially for woment with reduced sexual functioning. FUNDING: German Federal Ministry of Education and Research.

Bone mineral density in complete androgen insensitivity syndrome and the timing of gonadectomy.

OBJECTIVE: Low bone mineral density (BMD) has been reported in complete androgen insensitivity syndrome (CAIS), but the impact of timing of gonadectomy is not known. We aimed to assess the relationship between age of gonadectomy and BMD in women with CAIS. DESIGN: Retrospective analysis of pre- and post-gonadectomy parameters in women with CAIS attending an adult Disorders of Sex Development (DSD) clinic in a tertiary centre. PATIENTS: One hundred and thirteen women with CAIS. MEASUREMENTS: Dual-energy X-ray absorptiometry (DXA) before and after gonadectomy; and pre-gonadectomy hormone profile. RESULTS: Mean BMD was reduced (95% confidence interval); T-score -1.34 (-1.55 to -1.13; P<.001) at the lumbar spine and -0.3 (-0.49 to -0.12; P=.001) at the hip. There was no relationship between age of gonadectomy and BMD. Thirty-two subjects had BMD measured before or within 2 years of gonadectomy, and mean BMD was reduced (95% CI) at the lumbar spine; T-score: -1.05 (-1.54 to -0.57; P<.001), but was normal at the hip; T-score -0.04 (-0.35 to 0.28; P=.8). There was no relationship between BMD and history of hernia, testosterone, oestradiol or follicle stimulating hormone levels. Twelve subjects had DXA both before and after gonadectomy, and after 4.3 (1.7-12.8) years, there was no change in BMD. CONCLUSIONS: We found reduced BMD at the spine and hip in subjects with CAIS. We found no relationship between age of gonadectomy and BMD, and we also found no drop in BMD in subjects followed up after gonadectomy.

Aetiological bases of 46,XY disorders of sex development in the Hong Kong Chinese population.

OBJECTIVE: Disorders of sex development are due to congenital defects in chromosomal, gonadal, or anatomical sex development. The objective of this study was to determine the aetiology of this group of disorders in the Hong Kong Chinese population. SETTING: Five public hospitals in Hong Kong. PATIENTS: Patients with 46,XY disorders of sex development under the care of paediatric endocrinologists between July 2009 and June 2011. MAIN OUTCOME MEASURES: Measurement of serum gonadotropins, adrenal and testicular hormones, and urinary steroid profiling. Mutational analysis of genes involved in sexual differentiation by direct DNA sequencing and multiplex ligation-dependent probe amplification. RESULTS: Overall, 64 patients were recruited for the study. Their age at presentation ranged from birth to 17 years. The majority presented with ambiguous external genitalia including micropenis and severe hypospadias. A few presented with delayed puberty and primary amenorrhea. Baseline and post-human chorionic gonadotropin-stimulated testosterone and dihydrotestosterone levels were not discriminatory in patients with or without AR gene mutations. Of the patients, 22 had a confirmed genetic disease, with 11 having 5α-reductase 2 deficiency, seven with androgen insensitivity syndrome, one each with cholesterol side-chain cleavage enzyme deficiency, Frasier syndrome, NR5A1-related sex reversal, and persistent Müllerian duct syndrome. CONCLUSIONS: Our findings suggest that 5α-reductase 2 deficiency and androgen insensitivity syndrome are possibly the two most common causes of 46,XY disorders of sex development in the Hong Kong Chinese population. Since hormonal findings can be unreliable, mutational analysis of the SRD5A2 and AR genes should be considered the first-line tests for these patients.

Invasive Ductal Carcinoma in a 46,XY Partial Androgen Insensitivity Syndrome Patient on Hormone Therapy.

BACKGROUND: The hormonal management of patients with androgen insensitivity can be challenging. CASE: An illustrative case is presented of a newborn with ambiguous genitalia who was raised female. She was diagnosed as 46,XY Disorder of Sexual Development with partial androgen insensitivity. To induce puberty, conjugated equine estrogens were administered beginning at age 12. At age 13, she instead began taking combined oral contraceptives for maternal concerns about height and continued taking them for social reasons. Invasive ductal carcinoma was diagnosed at age 27, and the patient was treated with chemotherapy, radiation therapy, bilateral mastectomies, and endocrine therapy. SUMMARY AND CONCLUSION: The current literature is reviewed, and hormonal management and other risks for breast cancer are discussed.

Normal male sexual differentiation and aetiology of disorders of sex development.

Fetal sex development consists of three sequential stages: a) the undifferentiated stage, when identical primitive structures develop in the XY and XX embryos, b) gonadal differentiation into testes or ovaries, and c) the differentiation of internal and external genitalia, which depends on the action of testicular hormones. Disorders of sex development (DSD) may result from defects in any of these stages. Abnormal formation of the anlagen of internal and/or external genitalia in early embryonic development results in Malformative DSD. In patients with a Y chromosome, defects in testis differentiation drive to early-onset fetal hypogonadism affecting whole testicular function, a condition named Dysgenetic DSD. In Non-dysgenetic DSD, the underlying pathogenesis may involve early-onset fetal hypogonadism affecting specifically either Leydig or Sertoli cell function, or male hormone end-organ defects in patients devoid of fetal hypogonadism. Understanding the pathogenesis is useful for an efficient early diagnosis approach, which is necessary for adequate decision making in the management of DSD.

Complete Androgen Insensitivity Syndrome.

The incidence of Complete Androgen Insensitivity Syndrome (CAIS) is about 1 in 20,000. People with CAIS are normal appearing females, despite the presence of testes and a 46, XY chromosome constitution. We came across a case in which a 17 years old girl presented with the complaint of inguinal hernia and amenorrhea. Subsequent investigations were done revealing absence of female internal genitalia and the presence of abdominal mass, possibly testes. Syndrome has been linked to mutations in AR, the gene for the human Androgen Receptor, located at Xq11-12 leading to the insensitivity of the receptor to testosterone. Gonadectomy was performed and life long Hormone replacement therapy was advised.

A chemiluminescence-based assessment of androgen-binding activity in a large pedigree affected with androgen insensitivity syndrome.

We report a novel chemiluminescence (CL)-based method for assaying the ligand-binding activity of the androgen receptor. The central parts of this method are the utilization of the steroid CL marker as the replacement of the radioactive label in the conventional ligand-binding assay and the determination of the binding activity by the light measurement of the bound CL-label under an H(2)O(2)-microperoxidase system. The properties and reliability of this assay were investigated and verified using genital skin fibroblasts (GSF) from seven normal males. The method is precise (CV < 7% for both B(max) and K(d)) with high correlation coefficients (r > 0.93) in each Scatchard linear regression analysis. This assay can determine the androgen binding properties using only a quarter of the cells (approximately 40 000 cells/data point) of that required by the radiolabelling approach. The utility of the method was illustrated by binding experiment on the GSFs of several patients from a large Chinese family affected with androgen insensitivity syndrome. The familial distinct feature is that all patients shared an identical Arg840Cys substitution in the androgen receptor but displayed high phenotypic variation in disorders of male sexual development. The patients selected for the present study represent a wide spectrum of this phenotypic variation. This study thus provides insights on the pleiotropic effects of the mutation. In conclusion, the CL-based method can serve as an effective, precise and reliable replacement for the radiolabelling approach and has the advantages of simplicity, cost-effectiveness and health and environmental safety over the counterpart.

[Androgen insensitivity syndrome and co-activator disease].

Androgen insensitivity syndrome(AIS) is a clinical continuum of virilization disorders in XY males. Almost AIS is due to mutations in androgen receptor(AR) gene. Over 300 mutations in the AR gene have been reported. In addition, we have reported the case of complete AIS who has no mutations in AR gene, caused by co-activator abnormality. The recent advances in live-cell imaging techniques have developed a novel concept in AIS.

Disorders linked to insufficient androgen action in male children.

Virilization of the external genitalia in the male fetus requires testosterone and dihydrotestosterone (DHT), which is formed from testosterone by the action of the enzyme, 5alpha-reductase type 2 (5alphaR-2). Mediation of the effects of both testosterone and DHT requires a functional androgen receptor (AR) located in the cytoplasmic compartment of target cells. DHT (or testosterone) binding induces a conformational change which facilitates AR nuclear transport, phosphorylation and dimerization, ultimately regulating of the rate of transcription of androgen-dependent genes. Any event which impairs DHT formation (mutation within the 5alphaR-2 gene or 5alphaR-2 inhibitors) or normal function of the AR (mutation in the AR gene, antiandrogens) may result in insufficient androgen action in the male fetus and in subsequent undervirilization in the newborn. Hypospadias may be due to a defect in androgen action due to mutation of the 5alphaR-2 or of the AR gene. Mutation of unidentified genes is likely to underlie this displacement of the urethral meatus from the tip to the ventral side of the phallus. An aetiological role for environmental chemical products has been postulated, since ethnic as well as geographical differences in the incidence of hypospadias have been noted. Increasing evidence has been gathered indicating that widely used industrial and agricultural chemicals have deleterious effects on normal male sexual differentiation. Cryptorchidism and micropenis may represent an intersex phenotype, even if they are isolated. Aetiological factors include 5alphaR-2 gene mutation, AR gene mutation or environmental hormonal disruptors. In conclusion, several phenotypes have been attributed to insufficient androgen action during fetal life. Whereas mutations in the 5alphaR-2 gene and AR gene are natural, attention should be focused on environmental endocrine disruptors that are able to mimic steroid 5alpha-reductase deficiency or partial androgen insensitivity syndrome.

[Pathogenesis of androgen insensitivity syndrome].

Androgen plays an important role in male sexual differentiation and the defect of androgen action mainly due to androgen receptor abnormality causes androgen insensitivity syndrome (AIS). The number of the reports of AR gene mutations is AIS reaches more than 250, including structural mutations such as gene deletion and single base mutations. The intriguing characteristics of the single amino acid substitutions by single base mutations are that they tend to occur in restricted areas and on restricted bases, and that the same mutation sometimes shows phenotypic variation even among the family members. In addition, in some AIS cases, neither androgen binding abnormality nor AR gene mutation is detected. In these cases, other factors which take part in transcriptional activation by AR might be affected.

Pituitary apoplexy developed in a patient with androgen insensitivity syndrome.

At the age of 18, our patient was diagnosed as complete androgen insensitivity syndrome(AIS) based on androgen receptor studies in cultured genital skin fibroblasts. Compatible with this diagnosis, both testosterone and LH levels in her plasma were elevated as compared to levels in normal females. Later, the patient had been uneventful until she sought medical attention for headache at the age of 38. Magnetic resonance imaging (MRI) of the brain pointed to pituitary apoplexy. Since her symptoms were not alleviated by conservative therapy, neurosurgical decompression via a transsphenoidal approach was performed. A histopathological examination of a surgical specimen revealed that the pituitary hemorrhage occurred in an LH-producing adenoma. It is likely that the adenoma developed from gonadotroph hyperplasia which could exist in the AIS pituitary. It may be worth noting that this patient has never had a chance of receiving hormonal replacement therapy with estrogen and progesterone. Considering the fact that the majority of AIS patients are treated with gonadal steroids and such a treatment reestablishes an appropriate negative feedback on enhanced LH secretion, it is possible that the lack of hormonal therapy in our patient may have served as a precipitating factor for the apoplectic episode. Although we are not aware of any documented case report of pituitary apoplexy developed in AIS, such a pituitary emergency should be born in mind in the long-term follow-up of patients with AIS. In addition, it is also suggested that the hormonal replacement therapy with gonadal steroids may be recommended for AIS patients not only to endow them with physical characteristics as a woman but also to prevent the development of gonadotroph hyperplasia and possibly also of LH-producing adenoma in the pituitary.

[Testicular tumors in dogs: a literature review]. / Testistumoren bij de hond: een literatuuroverzicht.

The incidence of testicular tumours in dogs is higher than in other species. The main three types are: Sertoli cell tumour, seminoma, and Leydig cell tumour. Metastases are rare. Sertoli cell tumours, and to a lesser extent Leydig cell tumours, are often associated with feminization, which occurs in 19% and 5% of cases, respectively. Seminomas are rarely associated with feminization. Feminization seems to be the result of an excessive oestrogen production by the tumour. In severe cases this may lead to bone marrow depression. Atrophy of the contralateral testis is a common finding. It is not clear whether this is a result of feminization or of age because most tumours occur in older dogs. By investigating the morphology of the testis, and the endocrinological and fertility status of the dog this phenomena is hopefully going to be explained. Extra attention is given to the pathogenesis of feminization.

Alcoholic hypogonadism: hormonal response to clomiphene.

To investigate the androgen, weak androgen, estrogen, and gonadotrophin response to clomiphene in alcoholics, we determined in 63 male patients (25 with and 38 without liver cirrhosis) serum testosterone, sexual hormone binding protein (SHBG), dehidroepiandrosterone, androstenedione, LH, FSH, prolactin, and estradiol levels, on the first and the sixth day after admission, and after a course of 8 days of clomiphene 200 mg/day. The same test was performed on 15 healthy volunteers. Cirrhotic patients showed decreased basal testosterone levels and a loss of the circadian rhythm with recovery after clomiphene. Although basal testosterone levels in noncirrhotic alcoholics did not differ from those of the controls, there was a significant improvement after withdrawal. SHBG levels were higher in both groups of alcoholics than in controls, pointing to a worse degree of hypogonadism, because only the free hormone is active. Before the clomiphene test, serum LH and FSH levels were nonsignificantly higher in both groups of alcoholics than in the control group. After clomiphene both LH and FSH increased. Androstenedione and estradiol showed a (parallelism) similar behavior in alcoholic and in cirrhotic groups, showing in both cases higher levels than in the control group, and an increase after clomiphene, perhaps reflecting peripheral conversion of androgens to estrogens. Because clomiphene has no effect on the adrenal cortex, the increase of androstenedione after clomiphene points to its testicular origin (directly or after testosterone conversion) and not to an adrenal one. The highest serum estradiol levels were observed in cirrhotics with ascites or gynecomastia. We have not found any relation between serum hormone levels and alcohol intake nor with nutritional status.

Sex hormone changes induced by the parasite lead to feminization of the male host in murine Taenia crassiceps cysticercosis.

Female mice are more susceptible to Taenia crassiceps (TC) infection than males. However, after a month parasite load increases massively in both genders reaching thousands of parasites per host. The possibility of hormonal changes in the infected mice was envisaged. Sex hormones levels were assayed after different periods of infection, the parasites present in the peritoneal cavity were collected and gonads, uterus and seminal vesicles were weighed. In male mice, serum estradiol increased to levels 200 times their normal values whilst those of testosterone decreased 90% relative to controls. The weight of seminal vesicles was significantly diminished. Infected female mice also showed a slight increase in estrogen blood levels after 8 weeks of infection and the weight of the uterus was significantly increased relative to controls. Serum estradiol and testosterone were almost undetectable after gonadectomy. Cytokines such as IL-6 are capable of stimulating aromatase activity and we found that splenocytes from infected mice produced amounts of IL-6 higher than control as measured by ELISA. In conclusion T. crassiceps infection triggers a feminization process in the infected hosts. The gonads are required for the parasite to induce higher estrogen synthesis. IL-6 could be involved in the immunoendocrine mechanism used by the parasite to maintain a highly permissive environment for its rapid growth.

A substance secreted by rat Sertoli cells induces feminization of embryonic chick testes in vitro.

Male and female gonads from 7- to 9-day-old chick embryos were cultured for 6 days in Sertoli cell-conditioned medium or in serum-free medium to investigate the possible effect of substances secreted by rat Sertoli cells on chick gonad development. Histological analysis showed that whereas all female gonads proceed through normal ovarian development in both culture media, most of male gonads showed clear feminization only when cultured in Sertoli cell-conditioned medium; male gonads cultured in serum-free medium developed as normal testes. Because the only substance detected in our conditioned medium with the potential to cause these effects was sex-specific antigen (Sxs), our results provide further evidence that Sxs antigen may play a role in sexual differentiation in birds, and probably in mammals.