External Genital Abnormalities Research Articles

Effects of finasteride, a type 2 5-alpha reductase inhibitor, on fetal development in the rhesus monkey (Macaca mulatta).

In genetic male fetuses, dihydrotestosterone (DHT) plays an important role in normal prostatic and external genital differentiation. The enzyme steroid 5-alpha reductase (5 alpha R) catalyzes the conversion of testosterone (T) to DHT. The importance of 5 alpha R in sexual differentiation is evident from the study of human genetic males who congenitally lack this enzyme and consequently develop ambiguous genitalia. These individuals are specifically deficient in the type 2 isozyme, whereas the normal type 1 isozyme activity has been found. The purpose of this study was to determine 1) the suitability of the rhesus monkey for testing the safety of 5 alpha R inhibitors when administered during pregnancy and 2) the potential risk of administering a known type 2 5 alpha R inhibitor, finasteride, during the critical period of internal and external genital differentiation in rhesus monkeys. In vitro studies were also performed on selected rhesus monkey tissues to determine the distribution of the 5 alpha R isozymes. Gravid monkeys were treated once daily from gestational days (GD) 20 to 100. Sonographic monitoring was performed during the course of gestation to monitor viability, growth, and organ system development. Detailed fetal evaluations for developmental abnormalities were performed at term (GD 152 +/- 2). A group of 13 pregnant monkeys ("positive control") were given a high oral dose (2 mg/kg/day) of finasteride to demonstrate that inhibiting type 2 5 alpha R results in specific external genital abnormalities in male fetuses. Thirty-two pregnant monkeys were administered an intravenous (i.v.) formulation of finasteride at doses of 8, 80, or 800 ng/day. The highest i.v. dose selected was at least 60-750 times the semen levels of finasteride in man given orally 5 or 1 mg/day, respectively. Seventeen vehicle-control pregnant monkeys were also included. Administration of a high oral dose (2 mg/kg/day) of finasteride resulted in external genital abnormalities characterized by hypospadias, preputial adhesions to the glans, a small underdeveloped scrotum, a small penis, and a prominent midline raphe in male fetuses; however, no developmental abnormalities were seen in female fetuses. Similarly, no abnormalities were observed in either male or female fetuses of mothers given iv doses (8, 80, or 800 ng/day) of finasteride during pregnancy. The in utero sonographic findings in fetuses correlated with the gross findings at term. These studies have shown that external genital abnormalities can be produced in male monkey fetuses when exposed to a high oral dose (2 mg/kg/day) of finasteride, whereas no abnormalities were observed in fetuses exposed to the i.v. formulation of finasteride. Detailed in vitro studies demonstrated that the rhesus monkey also has two 5 alpha R isozymes (types 1 and 2) with a tissue distribution similar to that seen in man and, furthermore, that finasteride is a potent, mechanism-based inhibitor with selectivity for both human and rhesus type 2 5 alpha R. These studies have demonstrated that the monkey is a suitable model for assessing the safety of 5 alpha R inhibitors administered during pregnancy.

Limb reduction defects and renal dysplasia: Confirmation of a new, apparently lethal, autosomal recessive MCA syndrome

We report on 2 sibs, a male and a female, who died shortly after birth from respiratory failure. They combined growth retardation with a Potter-like face, complete phocomelia of the upper limbs, rib anomalies (mainly severe hypoplasia of the 6 upper ribs), renal dysplasia, and external genital abnormalities. We hypothesize that these cases represent evidence for the existence of the "new syndrome" described by Ulbright et al. (Am J Med Genet 17:667-668, 1984). This syndrome appears lethal because of the severe renal dysplasia that causes oligohydramnios and pulmonary hypoplasia. Its mode of inheritance seems to be autosomal recessive.

Embryotoxicity of a single dose of medroxyprogesterone acetate (MPA) and maternal serum MPA concentrations in cynomolgus monkey (Macaca fascicularis)

A single dose of MPA (Depo-Provera; Upjohn Co., Kalamazoo, Michigan) was administered intramuscularly to 12 time-mated pregnant cynomolgus monkeys on day 27 (+/- 2) of gestation at 25 mg/kg or at 100 mg/kg. Maternal blood samples were collected immediately prior to MPA injection and then at regular intervals until cesarean section at term (day 152 +/- 3). Infants in both dose groups had external genital abnormalities. Female infants in the low-dose groups had partial or complete labial fusion, prominent median raphe, and clitoral hypertrophy; at high doses (100 mg/kg), the female infants had complete labial fusion and a distinct penile urethra. MPA had an opposite effect on external genitalia of male infants. The penis was short and the scrotal swelling was absent or less conspicuous, and two males had hypospadias. The adrenal glands were significantly smaller (P less than 0.05) in infants of both sexes treated with 100 mg/kg. One of the infants treated with 25 mg/kg of MPA had a muscular ventricular septal defect. Serum concentrations of MPA were determined by radioimmunoassay in eight pregnant monkeys. In the 25 mg/kg group the patterns of MPA profiles in the serum were similar in all four animals. An initial peak occurred at 24-48 hr postinjection (2.7-9.6 ng/ml), followed by a slight decrease at 3 days postinjection (gestational day 30), and then a steady increase to maximum levels of 10-14 ng/ml occurring between gestational days 37 and 50. Serum levels gradually declined to concentrations below 5 ng/ml by midgestation in three of four monkeys. By comparison, both the patterns and magnitude of MPA concentration showed great interanimal variation in the 100 mg/kg group. MPA was present in cord blood at measurable concentrations in infants at both dose groups; the levels ranged from 0.6 to 8.3 ng/ml, corresponding to 40-72% of the maternal concentrations. These results demonstrate that a single injection of MPA during early pregnancy causes selective embryotoxicity in both male and female fetuses. Presence of high levels of MPA in maternal sera during the critical period of genital development can cause specific genital defects; however, the exact mechanism by which MPA causes these paradoxical genital abnormalities is unknown.

External genital abnormalities associated with Wilm's tumor: M. Beheshti, J.R.K. Mancer, B.E. Hardy, et al. Urology 24:130–133, (August), 1984

External genital abnormalities associated with Wilm's tumor: M. Beheshti, J.R.K. Mancer, B.E. Hardy, et al. Urology 24:130–133, (August), 1984

External genital abnormalities associated with wilms tumor

The records of 170 patients with unilateral and 18 patients with bilateral Wilms tumor and 6 patients with congenital mesoblastic nephroma were reviewed for abnormalities of the external genitalia. There were 4 patients with cryptorchism, 1 with hypospadias, 1 with mixed gonadal dysgenesis, and 3 with male pseudohermaphroditism. Of the group, these 9 patients had earlier symptoms; 6 of them were under two years old. Five patients (27.7 %) with bilateral Wilms tumors had external genital anomalies in contrast to only 4 (2.3 %) of those with unilateral tumors. One of the 9 children with genital anomalies had unilateral congenital mesoblastic nephroma; the others had Wilms tumor. In all cases the histologic subtypes were unusual. These observations substantiate the previously reported association between external genital abnormalities and Wilms tumor and also represent a somewhat higher than expected incidence. The children with this association are remarkable for the high frequency of a particular histologic type of tumor and for the high incidence of bilaterality. The high incidence of Wilms tumors in the male pseudohermaphrodite population presented suggests that such patients should be monitored for development of renal tumors.

CRYPTOPHTHALMOS, DYSCEPHALY, SYNDACTYLY AND RENAL APLASIA

A danish girl with incomplete, bilateral cryptophalmos together with assoicated craniofacial malformations, laryngeal hypoplasia, syndactyly, unilateral renal aplasia and slight external genital abnormalities is reported. Chromosomal abnormalities or metabolic disorders were not demonstrated. As the condition is extremely rare, some clinical and pathological fingings previosuly described in analogous cases are mentioned, together with a few pathogenetic mechanisms. Finally, a discussion regarding the aetiology of the condition is presented. Most authors are convinced that the malformative pattern is a syndrome with an autosomally recessive genetic basis. Added envronmental influence explains the wide range of manifestations and the varying gene expressivity.