Absent spermatogenesis despite early bilateral orchidopexy in 17-ketoreductase deficiency

Prepubertal and pubertal gonadal morphology, expression of cell lineage markers and hormonal evaluation in two 46,XY siblings with 17β-hydroxysteroid dehydrogenase 3 deficiency

OBJECTIVES

17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) deficiency results in insufficient biosynthesis of testosterone and consequently dihydrotestosterone. This is important for the fetal development of male genitalia. Thus, most 46,XY patients with 17β-HSD3 deficiency have a female appearance at birth and present with virilization at puberty. This study presents the differences in the clinical and hormonal data and analyses of gonadal characteristics in two siblings with 17β-HSD3 deficiency.

CASE PRESENTATION

Patient 1 presented with deepening of the voice and signs of virilization at puberty and increased serum levels of testosterone (T) of 10.9 nmol/L (2.9 SDS) and androstenedione (Δ4) of 27 nmol/L (3.3 SDS) were observed. The T/Δ4-ratio was 0.39. Patient 2 was clinically prepubertal at the time of diagnosis, but she also had increased levels of T at 1.97 nmol/L (2.9 SDS), Δ4 at 5 nmol/L (3.3 SDS), and the T/Δ4-ratio was 0.40, but without signs of virilization. Both siblings were diagnosed as homozygous for the splice-site mutation c.277+4A>T in intron 3 of HSD17B3. They were subsequently gonadectomized and treated with hormone replacement therapy. The gonadal histology was overall in accordance with pubertal status, although with a dysgenetic pattern in both patients, including Sertoli-cell-only tubules, few tubules containing germ cells, and presence of microliths.

CONCLUSIONS

Two siblings with 17β-HSD3 deficiency differed in pubertal development at the time of diagnosis and showed marked differences in their clinical presentation, hormonal profile, gonadal morphology and expression of cell lineage markers. Early diagnosis of 17β-HSD3 deficiency appears beneficial to ameliorate long-term consequences.

Establishing reproductive potential and advances in fertility preservation techniques for XY individuals with differences in sex development

BACKGROUND

Discordance between gonadal type and gender identity has often led to an assumption of infertility in patients with differences in sex development (DSD). However, there is now greater recognition of fertility being an important issue for this group of patients. Currently, gonadal tissue that may have fertility potential is not being stored for individuals with DSD and, where gonadectomy forms part of management, is often discarded. The area of fertility preservation has been predominantly driven by oncofertility which is a field dedicated to preserving the fertility of patients undergoing gonadotoxic cancer treatment. The use of fertility preservation techniques could be expanded to include individuals with DSD where functioning gonads are present.

METHODS

This is a systematic literature review evaluating original research articles and relevant reviews between 1974 and 2018 addressing DSD and fertility, in vitro maturation of sperm, and histological/ultrastructural assessment of gonadal tissue in complete and partial androgen insensitivity syndrome, 17β-hydroxysteroid dehydrogenase type 3 and 5α-reductase deficiency.

CONCLUSION

Successful clinical outcomes of ovarian tissue cryopreservation are paving the way for similar research being conducted using testicular tissue and sperm. There have been promising results from both animal and human studies leading to cryopreservation of testicular tissue now being offered to boys prior to cancer treatment. Although data are limited, there is evidence to suggest the presence of reproductive potential in the gonads of some individuals with DSD. Larger, more detailed studies are required, but if these continue to be encouraging, individuals with DSD should be given the same information, opportunities and access to fertility preservation as other patient groups.

Perspectives in Pediatric Pathology, Chapter 6. Male Undermasculinization

Normal male development requires three conditions: (1) adequate differentiation of the fetal testis; (2) synthesis and secretion of testicular hormones; and (3) effective action of these hormones on target organs. This requires the combined action of the inhibitory anti-müllerian hormone (AMH, secreted by Sertoli cells) to block the development of the uterus and fallopian tubes from the müllerian duct, together with the trophic stimulus of testosterone (a Leydig cell product), which leads to virilization of the wolffian ducts. Additionally, the development of external genitalia depends on the conversion of testosterone to dihydrotestosterone by the enzyme 5-α-reductase. Failure of any of these mechanisms leads to deficient virilization or the so-called "male pseudohermaphroditism" syndromes.

Characterization and linkage mapping of an ENU-induced mutant mouse with defective spermatogenesis

repro23 is an autosomal recessive mutation of the mouse generated by the N-ethyl-N-nitrosourea (ENU)-induced mutagenesis program at The Jackson Laboratory. The repro23/repro23 homozygous mouse shows male-specific infertility caused by defective spermatogenesis. In the present study, we investigated the testicular pathology of the affected mouse and performed linkage analysis to determine the chromosomal localization of the repro23 locus. Histological examination of the affected testis showed that the seminiferous epithelium of the repro23/repro23 mice contained spermatogonia and early stage spermatocytes, but no spermatids or spermatozoa. Immunohistochemical staining for Hsc70t, a spermatid specific protein, confirmed the absence of elongating spermatids. These findings indicated interruption of the spermatogenesis during meiosis in the repro23/repro23 mouse. By linkage analysis using 137 affected mice of F(2) progeny obtained from crosses between repro23/repro23 female and JF1/Ms (+/+) male mice, the repro23 locus was mapped to 2.2-Mb region of mouse chromosome 7. Although this region contains several potential candidate genes for the repro23 mutation, no gene already identified as a cause of defective spermatogenesis was in this region. Therefore, the gene responsible for the repro23 mutation is suggested to be a novel gene which plays an essential role in mammalian spermatogenesis.

Male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase 3 deficiency. Diagnosis, psychological evaluation, and management

Ten male pseudohermaphrodites with 17 beta-hydroxysteroid dehydrogenase 3 (17 beta-HSD3) deficiency were evaluated in 1 clinic with an average follow-up of 10.1 years. The diagnoses were made by demonstrating low to normal serum testosterone levels, high androstenedione levels, and high ratios of serum androstenedione to testosterone in the basal state or after treatment with human chorionic gonadotropin. The molecular features of the underlying mutations were identified in all 7 families. Two additional males in the same families are believed to be affected on the basis of history obtained from family members. All of the 46,XY individuals in these families were registered at birth and raised as females (despite the presence of ambiguous genitalia in all or most), and all virilized after the time of expected puberty due to a rise in serum testosterone to or toward the normal male range. The age at diagnosis varied from 4 to 37 years. Ten individuals were studied by the same psychologist, and change of gender role (social sex) from female to male occurred in 3 subjects and in the 2 presumed affected subjects not studied. The individual with the highest serum testosterone level maintained female sexual identity, and in 2 families some of the affected males changed gender role and others did not. Thus, while androgen action plays a role in the process, additional undefined psychological, social, and/or biologic factors must be determinants of gender identity/role behavior. Management of the 7 individuals who chose to maintain female sex roles included castration, clitoroplasty, vaginal enlargement procedures when appropriate, treatment of hirsutism, cricoid cartilage reduction, and estrogen replacement. Three of the 7 are married (2 twice), 1 is involved in a long-term heterosexual relationship, 1 is engaged to be married, and the other 2 are not married and not believed to be sexually active. The 3 subjects who changed gender role behavior to male underwent hypospadias repair, and 1 was given supplemental testosterone therapy. One of these men is divorced, and the other 2 (aged 29 and 35 years) are unmarried. The diagnosis in 8 of these subjects was made after the time of expected puberty; it is unclear whether the functional and social outcomes would have been different if the diagnosis had been made and therapy begun earlier in life.

Endocrine findings in male pseudohermaphroditism

Recent discoveries in molecular biology have much clarified the regulation and function of steroid converting enzymes. Most progress has been made in the area of cytochromes, which regulate the side chain cleavage of cholesterol (P-450 SCC) and the 17 alpha-hydroxylase- and 17,20-desmolase (or 17,20-lyase) activities (P-450 17 alpha), as well as in 3 beta-hydroxysteroid dehydrogenase. Nevertheless, there are some discrepancies between fundamental knowledge and clinical experience, which are difficult to understand: why is it possible, e.g., that cases with "pure" 17 alpha-hydroxylase or 17,20-desmolase deficiency exist, when there is only one cytochrome regulating both steps? After a brief review of clinical and biochemical findings in the various defects of testosterone biosynthesis, a case is discussed which is of interest in this respect.

Steroid 17β-hydroxysteroid dehydrogenase deficiency in man: an inherited form of male pseudohermaphroditism

Sixty-eight males with testicular 17β-hydroxysteroid dehydrogenase deficiency (17β-HSD) were identified among a highly inbred Arab population in Israel, and 45 studied over the last 15 years. The founders of this defect originated in the mountainous region of present Lebanon and Syria, but most of the families now live in Jerusalem, Hebron, the Tel-Aviv area, and in particular Gaza, where the frequency of affected males is estimated at 1 in 100 to 150. Affected individuals (46,XY) are born with ambiguity of the genitalia and reared as females until puberty. Thereafter marked virilization occurs, leading in many cases to the spontaneous adoption of a male gender role. Adults develop a male habitus with abundant body hair and beard, and the phallus and testes enlarge to adult proportions. Gender reassignment was possible only when enough erectile tissue was present at birth and developed into a normal size penis with systemic testosterone. male genitoplasty was performed in 15 children and 8 post-pubertal patients, and female genitoplasty in 2 children and 4 post-pubertal patients. In adults the defect is characterized by markedly increased concentrations of 4-androstendione (4-A) with borderline low to normal testosterone (T) levels, and a high 4-A/T ratio. Dihydrotestosterone (DHT) concentrations were either moderately decreased, normal, or high, and dehydroepiandrosterone levels were high. The estrogen pathway was also impaired, even though both estrone and estradiol-17β levels were elevated. Children had low basal levels of all androgens, but the defect could be demonstrated after prolonged stimulation with human chorionic gonadotropin. LH and FSH levels were very high after puberty, and normal in childhood. However, an over-response to gonadotropin-releasing hormone was found at all ages. Studies in testicular tissue revealed various abnormalities in steroid metabolism. Tissue from pre-pubertal patients metabolized progesterone (P) only to 4-A, while tissue from post-pubertal patients metabolized P to 16α- and 16β-hydroxyprogesterone (5.4- to 10.3-fold greater production), 17α-hydroxyprogesterone (5.4- to 8-fold smaller production), 4-A and T. 4-A was also metabolized to T, indicating that 17β-HSD was no longer deficient. Flow studies with equimolar concentrations of [¹⁴C]P and [³H]pregnenolone showed that the 5-ene pathway was the preferential one for androgen biosynthesis. Both in vivo and in vitro studies indicate that the severity of testicular 17β-HSD deficiency changes with age. Whereas the enzyme activity is absent in childhood, there is a progressive restoration after puberty. Androgen production increases progressively to normal so that T and DHT concentrations are sufficiently high to gradually induce somatic and genital virilization, thus enabling an adequate male gender function.