Male pseudohermaphroditism in XY children with female phenotype

Androgen Insensitivity Syndrome with Bilateral Gonadal Sertoli Cell Lesions, Sertoli-Leydig Cell Tumor, and Paratesticular Leiomyoma: A Case Report and First Systematic Literature Review

Androgen insensitivity syndrome (AIS) is a rare Mendelian disorder caused by mutations of the androgen receptor (AR) gene on the long arm of the X chromosome. As a result of the mutation, the receptor becomes resistant to androgens, and hence, karyotypically male patients (46,XY) carry a female phenotype. Their cryptorchid gonads are prone to the development of several types of tumors (germ cell, sex cord stromal, and others). Here, we report a 15-year-old female-looking patient with primary amenorrhea who underwent laparoscopic gonadectomy. Histologically, the patient's gonads showed Sertoli cell hamartomas (SCHs) and adenomas (SCAs) with areas of Sertoli-Leydig cell tumors (SLCTs) and a left-sided paratesticular leiomyoma. Rudimentary Fallopian tubes were also present. The patient's karyotype was 46,XY without any evidence of aberrations. Molecular genetic analysis of the left gonad revealed two likely germline mutations-a pathogenic frameshift deletion in the AR gene (c.77delT) and a likely pathogenic missense variant in the RAC1 gene (p.A94V). Strikingly, no somatic mutations, fusions, or copy number variations were found. We also performed the first systematic literature review (PRISMA guidelines; screened databases: PubMed, Scopus, Web of Science; ended on 7 December 2023) of the reported cases of patients with AIS showing benign or malignant Sertoli cell lesions/tumors in their gonads (n = 225; age: 4-84, mean 32 years), including Sertoli cell hyperplasia (1%), Sertoli cell nodules (6%), SCHs (31%), SCAs (36%), Sertoli cell tumors (SCTs) (16%), and SLCTs (4%). The few cases (n = 14, 6%; six SCAs, four SCTs, two SLCTs, and two SCHs) with available follow-up (2-49, mean 17 months) showed no evidence of disease (13/14, 93%) or died of other causes (1/14, 7%) despite the histological diagnosis. Smooth muscle lesions/proliferations were identified in 19 (8%) cases (including clearly reported rudimentary uterine remnants, 3 cases; leiomyomas, 4 cases). Rudimentary Fallopian tube(s) were described in nine (4%) cases. Conclusion: AIS may be associated with sex cord/stromal tumors and, rarely, mesenchymal tumors such as leiomyomas. True malignant sex cord tumors can arise in these patients. Larger series with longer follow-ups are needed to estimate the exact prognostic relevance of tumor histology in AIS.

Clinical, cytogenetic and molecular analysis of androgen insensitivity syndromes from south Indian cohort and detection and in-silico characterization of androgen receptor gene mutations

Rare cases of 9 complete androgen insensitivity syndromes, 9 cases of partial androgen insensitivity syndromes and equal number of male control samples were selected for this study. Few strong variations in clinical features were noticed; Giemsa banded metaphase revealed a 46,XY karyotype and the frequency of chromosome aberrations were significantly higher when compared with control samples. DNA sequence analysis of the androgen receptor gene of androgen insensitivity syndromes revealed three missense mutations - c.C1713>G resulting in the replacement of a highly conserved histidine residue with glutamine p.(His571Glu) in DNA-binding domain, c.A1715>G resulting in the replacement of a highly conserved tyrosine residue with cysteine p.(Tyr572Cys) in DNA-binding domain and c.G2599>A resulting in the replacement of a highly conserved valine residue with methionine p.(Val867Met) in ligand-binding domain of androgen receptor gene respectively. The heterozygous type of mutations c.C1713>G and c.G2599>A observed in mothers of the patients for familial cases concluding that the mutation was inherited from the mother. The novel mutation c.C1713>G is reported first time in androgen insensitivity syndrome. In-silico analysis of mutations observed in androgen receptor gene of androgen insensitivity syndrome predicted that the substitution at Y572C and V867M could probably disrupt the protein structure and function.

Regulation of Wolffian Duct Development

Wolffian ducts (WDs) are the embryonic structures that form the male internal genitalia. These ducts develop in both the male and female embryo. However, in the female they subsequently regress, whereas in the male they are stabilised by testosterone. The WDs then develop into separate but contiguous organs, the epididymis, vas deferens and seminal vesicles. Recently, considerable progress has been made in identifying genes that are involved in these different stages of development which is described in this review. In addition, WD development in (atypical forms of) cystic fibrosis and intersex disorders, such as the complete androgen insensitivity syndrome, 17beta-hydroxysteroid dehydrogenase deficiency and LH-receptor defects, is discussed. The apparent increase in male reproductive tract disorders is briefly discussed from the perspective of the potential endocrine-disrupting effects of the numerous chemicals in the environment to which the developing male foetus can be exposed.

Testicular development in the complete androgen insensitivity syndrome

The complete androgen insensitivity syndrome (CAIS), caused by mutations in the androgen receptor (AR) gene, is associated with abnormal testicular development and an increased risk of germ cell malignancy. Previous histological studies in CAIS have selected patients purely on the basis of clinical diagnosis and were mostly based on small numbers, many of whom were post-pubertal. Here, we present 44 cases of CAIS, each with molecular pathological confirmation of an AR mutation. The median age at gonadectomy was 5.5 years (5.5; IQR 1-13). We have been able, therefore, to investigate testicular development in infancy, childhood and puberty, and estimate the incidence of premalignant change in this series. In addition, we have investigated whether the presence of epididymides and/or vasa deferentia in CAIS, previously shown to be associated with residual activity of mutant ARs, is related to a particular testicular phenotype. Epididymides/vasa deferentia were present in 36% of cases and these patients showed varying degrees of seminiferous tubule maturation at puberty above those without epididymides/vasa deferentia (p = 0.003). There were no other histological differences between these patient groups. In both groups, features of testicular degeneration and dysgenesis were present and germ cell development was delayed, with prolonged expression of the gonocyte markers, placental-like alkaline phosphatase and activator protein-2gamma. Germ cell numbers rapidly declined after the first year of life (R(2) = 0.42). Only two cases of carcinoma in situ were identified in our study and both patients were postpubertal (17 and 53 years). From these results and the literature, we conclude that the risk of premalignant change in germ cells is low before and during puberty. Patients can be advised, therefore, that gonadectomy can be delayed to allow for a natural puberty, with low risk of malignant transformation. Our study only included one patient over 18 years, so we cannot comment on the risk of malignant transformation in later life.

Wide variation in androgen receptor dysfunction in complete androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is a disorder of male sexual differentiation caused by mutations in the androgen receptor (AR) gene. The partial form (PAIS), associated with varying degrees of receptor dysfunction, presents with a range of undervirilization phenotypes. The complete form (CAIS) is characterized by normal female external appearance at birth. In these cases the receptor is often absent or inactive. However, cases have been described where the mutant receptor concerned has considerable residual activity in in vitro assays. Here we describe the effects of five mutations, Gly750Asp, Leu762Phe, Ala765Thr, Asp864Asn and Leu907Phe, identified in complete androgen insensitivity patients. In vitro assays of mutant androgen receptors expressed in a mammalian cell line showed that the Gly750Asp, Leu762Phe and Ala765Thr mutations cause almost complete loss of androgen-binding activity, suggesting that these residues are critical for ligand binding. However, receptors with Asp864Asn and Leu907Phe, although defective, were capable of considerable binding and transactivation activity. Given that some mutations identified in PAIS patients have a more severe effect on androgen receptor function than two CAIS mutations described here, these results provide further evidence that other factors, including genetic background, can have a significant impact on the phenotype associated with a particular AR mutation.

Regulation of rat testis gonocyte proliferation by platelet-derived growth factor and estradiol: identification of signaling mechanisms involved

To determine what factors regulate gonocyte proliferation in newborn rats, we first examined the expression of several signal transduction molecules by immunocytochemistry in 3-day-old rat testis sections. We found that gonocytes specifically expressed the iota and zeta isoforms of protein kinase (PK) C (PKC) and the phosphatidylinositol 3-kinase (PI3-K). Because both the zeta PKC and PI 3-K have been shown to play a role in platelet-derived growth factor (PDGF)-induced cell proliferation, we examined the effects of PDGF on gonocytes. For this, we developed a method to obtain highly purified and viable gonocytes in culture. After enzymatic digestion, differential adhesion, and two successive gradient fractionations, the gonocyte suspension obtained was over 90% pure, as assessed by light microscopy. The viability of cultured gonocytes exceeded 90% after 48 h in the presence of 2.5% FBS used as a survival factor. Immunodetection studies showed that isolated gonocytes expressed zeta PKC, PI 3-K, and the PDGF receptor. Treatment with 10 ng/ml PDGF induced a 4-fold increase of bromodeoxyuridine incorporation into gonocytes (from 5% proliferative gonocytes under basal conditions to 20% in the presence of PDGF). Because neonatal Sertoli cells secrete high levels of the growth promoting steroid, 17 beta-estradiol, we also tested its effect and found that it induced gonocyte proliferation at a level comparable with that of PDGF and that this effect was blocked by the estrogen receptor antagonist, ICI 164384. The combination of PDGF and estradiol, however, was not additive, suggesting that their effects were mediated by common molecular target(s). These results demonstrate that PDGF and estradiol activate gonocyte proliferation in vitro, suggesting that they may act as the physiological regulators of gonocyte development in vivo.