Primary Amenorrhea Due to Anatomical Abnormalities of the Reproductive Tract: Molecular Insight

Congenital anomalies of the female reproductive tract that present with primary amenorrhea involve Müllerian aplasia, also known as Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS), and cervical and vaginal anomalies that completely obstruct the reproductive tract. Karyotype abnormalities do not exclude the diagnosis of MRKHS. Familial cases of Müllerian anomalies and associated malformations of the urinary and skeletal systems strongly suggest a complex genetic etiology, but so far, the molecular mechanism in the vast majority of cases remains unknown. Primary amenorrhea may also be the first presentation of complete androgen insensitivity syndrome, steroid 5α-reductase type 2 deficiency, 17β-hydroxysteroid dehydrogenase type 3 deficiency, and Leydig cells hypoplasia type 1; therefore, these disorders should be considered in the differential diagnosis of the congenital absence of the uterus and vagina. The molecular diagnosis in the majority of these cases can be established.

Role of Hepatic Glucocorticoid Receptor in Metabolism in Models of 5αR1 Deficiency in Male Mice

Inhibition of 5α-reductases impairs androgen and glucocorticoid metabolism and induces insulin resistance in humans and rodents. The contribution of hepatic glucocorticoids to these adverse metabolic changes was assessed using a liver-selective glucocorticoid receptor (GR) antagonist, A-348441. Mice lacking 5α-reductase 1 (5αR1-KO) and their littermate controls were studied during consumption of a high-fat diet, with or without A-348441(120 mg/kg/d). Male C57BL/6 mice (age, 12 weeks) receiving dutasteride (1.8 mg/kg/d)) or vehicle with consumption of a high-fat diet, with or without A-348441, were also studied. In the 5αR1-KO mice, hepatic GR antagonism improved diet-induced insulin resistance but not more than that of the controls. Liver steatosis was not affected by hepatic GR antagonism in either 5αR1KO mice or littermate controls. In a second model of 5α-reductase inhibition using dutasteride and hepatic GR antagonism with A-348441 attenuated the excess weight gain resulting from dutasteride (mean ± SEM, 7.03 ± 0.5 vs 2.13 ± 0.4 g; dutasteride vs dutasteride plus A-348441; P < 0.05) and normalized the associated hyperinsulinemia after glucose challenge (area under the curve, 235.9 ± 17 vs 329.3 ± 16 vs 198.4 ± 25 ng/mL/min; high fat vs high fat plus dutasteride vs high fat plus dutasteride plus A-348441, respectively; P < 0.05). However, A-348441 again did not reverse dutasteride-induced liver steatosis. Thus, overall hepatic GR antagonism improved the insulin resistance but not the steatosis induced by a high-fat diet. Moreover, it attenuated the excessive insulin resistance caused by pharmacological inhibition of 5α-reductases but not genetic disruption of 5αR1. The use of dutasteride might increase the risk of type 2 diabetes mellitus and reduced exposure to glucocorticoids might be beneficial.

Initial assessment of a child with suspected disorder of sex development

Disorders of sex development (DSD) are defined as discrepancy between chromosomal, gonadal and anatomic sex. The basic principles for the management of DSD include a multidisciplinary approach for gender assignment. Clinical assessment includes a detailed history and examination of external genitalia. Most of the disorders with symmetrical gonades indicate hormonal cause while asymmetrical gonades are found in chromosomal DSDs. Karyotyping will indicate a 46XX DSD, 46 XY DSD or mosicism. Internal anatomy is defined by ultrasonography, genitoscopy and laparoscopy. Human chorionic gonadotrophins (hCG) stimulation test is carried out in under-virilised males to see the function of Leydig cells in testes. The Most common cause of 46XX DSD is congenital adrenal hyperplasia (CAH). The decision of gender assignment surgery is to be taken in a multidisciplinary environment and with informed consent of the parents. Most of 46 XX CAH patients, even if markedly virilised, and 46 XY complete androgen insensitivity syndrome are raised as females. Similarly, most of 5-α reductase deficiency and 17-β hydroxysteroid dehydrogenase deficiency patients are assigned to the male gender. The decision in cases of mixed gondal dysgenesis and ovotesticular DSD is based on the development of external and internal genitalia. Patients with androgen biosynthetic defects, partial androgen insensitivity syndrome are usually assigned to the male gender.

Adverse effects of 5α-reductase inhibitors: What do we know, don't know, and need to know?

Steroids are important physiological orchestrators of endocrine as well as peripheral and central nervous system functions. One of the key processes for regulation of these molecules lies in their enzymatic processing by a family of 5α-reductase (5α-Rs) isozymes. By catalyzing a key rate-limiting step in steroidogenesis, this family of enzymes exerts a crucial role not only in the physiological control but also in pathological events. Indeed, both 5α-R inhibition and supplementation of 5α-reduced metabolites are currently used or have been proposed as therapeutic strategies for a wide array of pathological conditions. In particular, the potent 5α-R inhibitors finasteride and dutasteride are used in the treatments of benign prostatic hyperplasia (BPH), as well as in male pattern hair loss (MPHL) known as androgenetic alopecia (AGA). Recent preclinical and clinical findings indicate that 5α-R inhibitors evoke not only beneficial, but also adverse effects. Future studies should investigate the biochemical and physiological mechanisms that underlie the persistence of the adverse sexual side effects to determine why a subset of patients is afflicted with such persistence or irreversible adverse effects. Also a better focus of clinical research is urgently needed to better define those subjects who are likely to be adversely affected by such agents. Furthermore, research on the non-sexual adverse effects such as diabetes, psychosis, depression, and cognitive function are needed to better understand the broad spectrum of the effects these drugs may elicit during their use in treatment of AGA or BPH. In this review, we will summarize the state of art on this topic, overview the key unresolved questions that have emerged on the pharmacological targeting of these enzymes and their products, and highlight the need for further studies to ascertain the severity and duration of the adverse effects of 5α-R inhibitors, as well as their biological underpinnings.

Female mice with deletion of Type One 5α-reductase have reduced reproductive responding during proestrus and after hormone-priming

The capacity to form progesterone (P₄)'s 5α-reduced metabolite, 5α-pregnan-3α-ol-20-one (3α,5α-THP; a.k.a. allopregnanolone), in the brain may be related to facilitation of lordosis among estrogen-primed (E₂) mice. We investigated this idea further by comparing effects of endogenous and exogenous progestogens in mice that are deficient in the Type One 5α-reductase enzyme (5α-reductase knockout mice; 5α-RKO), and their wildtype counterparts for sexual behavior. Comparisons were made following administration of progestogens that are expected to increase 3α,5α-THP or not. Sexual receptivity of 5α-RKO mice and their wildtype counterparts was examined when mice were naturally-cycling (Experiment 1); ovariectomized (OVX), E₂-primed (10 μg, subcutaneous; SC) and administered P₄ (0, 125, 250, or 500 μg SC; Experiment 2); and OVX, E₂-primed and administered P₄, medroxyprogesterone acetate (MPA, 4 mg/kg, SC, which does not convert to 3α,5α-THP) or 3α,5α-THP (4 mg/kg, SC; Experiment 3). The percentage of mounts that elicited lordosis (lordosis quotient) or aggression/rejection behavior (aggression quotient), as well as the quality of lordosis (lordosis rating), was scored. Wildtype, but not 5α-RKO, mice in behavioral estrus demonstrated significantly greater lordosis quotients and lordosis ratings, but similar aggression quotients, compared to their diestrous counterparts. Among OVX and E₂-primed mice, P₄ facilitated lordosis of wildtype, but not 5α-RKO, mice. MPA neither facilitated lordosis of wildtype, nor 5α-RKO mice. 3α,5α-THP administered to wildtype or 5α-RKO mice increased lordosis quotients and lordosis ratings and decreased aggression quotients. 3α,5α-THP levels in the midbrain, one brain region important for sexual behavior, were increased during behavioral estrus, with P4 administered to WT, but not 5α-RKO mice, and 3α,5α-THP administered to WT and 5α-RKO mice. MPA did not increase 3α,5α-THP. Thus, deletion of Type One 5α-reductase among female mice may attenuate reproductive responding during the estrous cycle and after hormone-priming.

Bone mineral density in the complete androgen insensitivity and 5alpha-reductase-2 deficiency syndromes

CONTEXT

Subjects with complete androgen insensitivity (CAI) and 5alpha-reductase-2 deficiency (5alphaRD-2) are natural human models to study the direct effect of androgens on bone mineral density (BMD).

OBJECTIVE

The objective of this study was to test the hypothesis that androgens have a direct effect on BMD in men.

DESIGN

This was a prospective, observational study (1989-1999) using dual energy x-ray absorptiometry.

SETTING

The study was set in an outpatient specialty referral center.

PATIENTS OR OTHER PARTICIPANTS

All known subjects with these conditions (12 CAI and 16 5alphaRD-2) from diverse sociodemographic backgrounds were recruited for the study.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE

Mean Z score and weight-matched Z score at lumbar spine and femoral neck for CAI and 5alphaRD-2 subjects were determined.

RESULTS

Twelve CAI subjects had mean Z score at L2-L4 of -2.84 (+/-0.97, P < 0.001) and a mean weight-matched Z score of -2.52 (+/-0.94, P < 0.001). The mean Z score at the femoral neck was -1.33 (+/-0.91, P < 0.001) and the mean weight-matched Z score was -1.10 (+/-0.82, P = 0.001). Sixteen 5alphaRD-2 subjects had a mean Z score at L2-L4 of -0.84 (+/-1.29, P = 0.02) and a mean weight-matched Z score for 15 of 16 patients of -0.44 (+/-1.08, P = 0.14). The mean Z score at the femoral neck was 0.14 (+/-1.02, P = 0.58) and the mean weight-matched Z score for 15 of 16 patients was 0.49 (+/-0.94, P = 0.06). Therefore, in CAI subjects, BMD was significantly decreased in the spine and hip. 5alphaRD-2 subjects had normal BMD values.

CONCLUSIONS

1) Androgens are of direct importance in the development and/or maintenance of BMD; and 2) testosterone and/or low levels of dihydrotestosterone appear to be sufficient for BMD development and/or maintenance.

Sigmoid colon vaginoplasty in children

BACKGROUND

Vaginal construction is necessary for the patients with aplasia of Mullerian ducts, testicular feminisation and androgen insensitivity syndromes. Many methods of vaginal construction have been described. We report here the outcomes of six adolescent patients who underwent sigmoid colon vaginoplasty with special emphasis on the surgical technique and outcomes.

PATIENTS AND METHODS

Between 1990 and 2003, six patients underwent sigmoid vaginoplasty after a diagnosis of 5alpha-reductase deficiency (n = 3), testicular feminisation (n = 2) or vaginal atresia (n = 1). The mean age was 16 years (13 to 18). Wide spectrum antibiotics and whole-gut preparation were used in all cases. A 15-20 cm segment of sigmoid colon was pulled through the retrovesical tunnel. The proximal end was closed in two layers in patients with 5alpha-reductase deficiency and with testicular feminisation. A distal anastomosis was carried out to the opening made on the vaginal plate (5alpha-reductase deficiency) or on the tip of the shallow rudimentary vagina (testicular feminisation). The sigmoid segment was interposed between the blind end of the atretic vagina and the perineum in the patient with vaginal atresia. Patients were instructed to perform daily vaginal irrigation. The neovagina was examined and calibrated under anaesthesia. No routine vaginal dilatation was recommended.

RESULTS

All but one patient had an uneventful postoperative period and were discharged within 7-8 days. All patients had an excellent cosmetic result with an appropriate vaginal length. One of the patients experienced late stenosis of the introitus which responded to dilatations. Mucus discharge was not a significant problem. The patient with vaginal atresia (Bardet-Biedl syndrome) experienced deep vein thrombosis, renal failure and sepsis, resulting in death.

CONCLUSION

Sigmoid colon vaginoplasty is a special procedure which appears appropriate for the construction of a new vagina in children. A sigmoid colon neovagina meets all necessary criteria after a vaginoplasty. It provides an adequate diameter and length, and produces less scar tissue in the perineum. It is self-moistening, easily adaptable to the uterus, cervix and rudimentary atretic vaginal segments and does not require routine dilatation. Mild stenosis of the introitus can be treated by dilatations and revision can be easily performed in severely stenotic cases. On the other hand, the patient may face morbidity after laparotomy and other serious complications may occur due to accompanying diseases.

Effects of male sex hormones on gender identity, sexual behavior, and cognitive function

Androgens, the male sex hormones, play an essential role in male sexual differentiation and development. However, the influence of these sex hormones extends beyond their roles in sexual differentiation and development. In many animal species, sex hormones have been shown to be essential for sexual differentiation of the brain during development and for maintaining sexually dimorphic behavior throughout life. The principals of sex determination in humans have been demonstrated to be similar to other mammals. However, the hormonal influence on sexual dimorphic differences in the nervous system in humans, sex differences in behaviors, and its correlations with those of other mammals is still an emerging field. In this review, the roles of androgens in gender and cognitive function are discussed with the emphasis on subjects with androgen action defects including complete androgen insensitivity due to androgen receptor mutations and 5alpha-reductase-2 deficiency syndromes due to 5alpha-reductase-2 gene mutations. The issue of the complex interaction of nature versus nurture is addressed.

Cytogenetics and etiology of ambiguous genitalia in 120 pediatric patients

BACKGROUND

A newborn with ambiguous genitalia needs prompt evaluation to detect life-threatening conditions (e.g., salt-losing crisis in congenital adrenal hyperplasia [CAH]) and gender assignment. Sex assignment in these children continues to be a challenging diagnostic and therapeutic problem. We studied the causes and characteristics of ambiguous genitalia in children who were referred to a cytogenetic laboratory.

PATIENTS AND METHODS

We retrospectively reviewed a total of 120 medical records of patients with a primary indication of ambiguous genitalia that were referred to the cytogenetic lab for karyotyping during the period of 1989 to 1999. Diagnosis was based on a clinical impression from the primary physician, who was primarily a staff pediatrician, endocrinologist and/or pediatric urologist.

RESULTS

CAH was the underlying cause of ambiguous genitalia in 41 of 63 patients with ambiguity due to endocrine causes; 39 of these patients showed a 46,XX karyotype and 2 cases were 46,XY (both the 46,XY patients had 3 beta-hydroxylase deficiency). In 57 patients, ambiguous genitalia were due to congenital developmental defects. The most common endocrine case of ambiguous genitalia was 21-OH deficiency. Seven patients were classified as idiopathic with six showing the 46,XY and one the 46,XX karyotype. Gender was reassigned at birth or at diagnosis in 15 patients.

CONCLUSION

The etiology of ambiguous genitalia is variable. The physician managing these families could minimize the trauma of having a child with unidentified sex by providing appropriate genetic counseling so that the parents can make an early decision. Prenatal DNA testing in at-risk families should be considered and appropriate therapy offered to minimize or prevent genital ambiguity.

Progesterone enhances motor, anxiolytic, analgesic, and antidepressive behavior of wild-type mice, but not those deficient in type 1 5 alpha-reductase

The importance of progesterone's (P(4)) metabolism by the 5 alpha-reductase type I enzyme was examined in homozygous and heterozygous 5 alpha-reductase type I knockout mice and their wild-type siblings. P(4) (1.0 mg) or vehicle was administered and effects on motor, anxiety, nociceptive, and depression behavior were observed. After testing, whole-brain progesterone and 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP) levels were determined by radioimmunoassay. Motor behavior in the horizontal crossing and open field tasks of 5 alpha-reductase-deficient mice administered P(4) was similar to vehicle control mice and significantly reduced compared to wild-type mice administered P(4). In the open field, 5 alpha-reductase-deficient mice administered P(4) had a similar number of central entries as did vehicle control mice, both were lower than central entries of P(4)-administered wild-type mice. However, in the plus maze, P(4) to 5 alpha-reductase-deficient or wild-type mice significantly increased open arm activity compared to vehicle-administered control mice. P(4) to wild-type, but not 5 alpha-reductase-deficient mice, significantly increased latencies to lick front and back paws in response to radiant heat stimuli compared to vehicle administration to control mice. In the forced swim test, 5 alpha-reductase-deficient mice administered P(4) were similar to vehicle control mice and the latency to immobility was significantly decreased, and the duration of immobility was significantly increased, compared to wild-type mice administered P(4). Thus, these data suggest metabolism by the 5 alpha-reductase type I enzyme may mitigate P(4)'s effects on some tasks of motor, anxiety, nociception, and depression behavior.