Familial male pseudohermaphroditism with gynaecomastia due to 17 beta-hydroxysteroid dehydrogenase deficiency. A report of 3 cases

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.

Towards improved genetic diagnosis of human differences of sex development

Despite being collectively among the most frequent congenital developmental conditions worldwide, differences of sex development (DSD) lack recognition and research funding. As a result, what constitutes optimal management remains uncertain. Identification of the individual conditions under the DSD umbrella is challenging and molecular genetic diagnosis is frequently not achieved, which has psychosocial and health-related repercussions for patients and their families. New genomic approaches have the potential to resolve this impasse through better detection of protein-coding variants and ascertainment of under-recognized aetiology, such as mosaic, structural, non-coding or epigenetic variants. Ultimately, it is hoped that better outcomes data, improved understanding of the molecular causes and greater public awareness will bring an end to the stigma often associated with DSD.

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.

Germ cell neoplasia in situ complicating 17β-hydroxysteroid dehydrogenase type 3 deficiency

17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) deficiency is an autosomal recessive disorder of male sex development that results in defective testosterone biosynthesis. Although mutations in the cognate HSD17B3 gene cause a spectrum of phenotypic manifestations, the majority of affected patients are genetic males having female external genitalia. Many cases do not present until puberty, at which time peripheral conversion of androgen precursors causes progressive virilization. Measurement of the testosterone-to-androstenedione ratio is useful to screen for 17βHSD3 deficiency, and genetic analysis can confirm the diagnosis. As some individuals with 17βHSD3 deficiency transition from a female sex assignment to identifying as males, providers should ensure stable gender identity prior to recommending irreversible treatments. Gonadectomy is indicated to prevent further virilization if a female gender identity is established. The risk of testicular neoplasia is unknown, a point which should be discussed if patients elect to transition into a male gender role.

Concepts and Updates in the Evaluation and Diagnosis of Common Disorders of Sexual Development

Our understanding of disorders of sexual differentiation (DSD) has evolved from aberrations of human genital development to a broad group of complex disorders of etiological and functional significance. The unique challenge of DSD conditions is that they create a cause for significant angst and concern for both parents and physician, as they frequently lead to questions with regards to gender assignment, surgically corrective options, long-term outlook regarding gender identity, and reproductive potential. To further add to the burden, many patients who present with genital abnormalities do not have a clear explanation as to the underlying basis of their disorder. This review looks at DSD from a pediatric urology point of view with emphasis on evaluation, diagnosis, and algorithm for work-up. We also discuss novel genetic analysis techniques and their value in diagnosis. Overall, this is an all-encompassing review on a diagnostic approach to DSD, with inclusion of recent developments and controversies, which will benefit urologists and other physicians alike.

17βHSD-3 enzyme deficiency due to novel mutations in the HSD17B3 gene diagnosed in a neonate

17-β-Hydroxysteroid dehydrogenase type 3 (17βHSD-3) is present almost exclusively in the testes, and converts androstenedione (A) to testosterone (T). 17βHSD-3 deficiency is rare. The diagnosis can be missed in early childhood as the clinical presentation may be subtle. The most frequent presentation of 17 HSD-3 deficiency is a 46,XY individual with female external genitalia, labial fusion and a blind ending vagina, with or without clitoromegaly. A low testosterone/androstenedion (T/A) ratio is suggestive of 17βHSD-3 deficiency, and such diagnosis can be confirmed with molecular genetic studies. A 12-day newborn was referred to our hospital because of palpable gonads in the labia majora. On physical examination, the baby had female external genitalia and palpable gonads in the labia majora. T/A ratio was 0.26 and the diagnosis was 17βHSD-3 deficiency, which was confirmed by the evidence of compound heterozygousity novel frameshift mutations in exon 9 and 10 of HSD17B3 gene.

17beta-Hydroxysteroid dehydrogenase-3 deficiency: from pregnancy to adolescence

OBJECTIVE

Aim of this study is to report on basal clinical phenotype and follow up after diagnosis, of patients with 17beta-hydroxysteroid-dehydrogenase type 3 (17beta-HSD3) deficiency in Italy.

SETTING

Pediatric Endocrine Departments, University Hospitals.

PATIENTS

The cases of 5 Italian subjects affected by 17beta-HSD3 deficiency are presented in this study.

INTERVENTIONS

Laboratory and genetic assessment. Gonadectomy and female sex assignment (4 patients) or GnRH analog therapy to regress puberty and gender identity disorder (1 patient).

RESULTS

Presentation lasted from pregnancy (pre-natal diagnosis of a 46,XY fetus with female external genitalia) to infancy (inguinal hernia containing testes/clitoromegaly) and adolescence (virilisation). All subjects but one (subject 1, Central-Northern Italy) were from small areas of Southern Italy. Endocrine data (baseline and/or stimulated testosterone/ Delta4-androstenedione ratio) were informative. Two girls were homozygous for 17beta-HSD3 gene mutations (G289S/G289S; R80W/R80W), while the others were compound heterozygous (IVS325+4 A>T/A203V; L212Q/M235V; R80W/A235E). Four patients were confirmed as females and were well-adjusted with assigned sex; gender identity disorder improved during treatment with GnRH analog in the last subject.

CONCLUSIONS

17betaHSD3 deficiency may present from pregnancy to puberty for different clinical issues. Albeit testosterone/Delta4-androstenedione ratio represents the most accurate endocrine marker to diagnose the disorder, hCGstimulation is mandatory in pre-puberty. Molecular analysis of 17beta-HSD3 gene should be performed to confirm the diagnosis. Temporary GnRH analog treatment may regress gender identity disorder and provide time to confirm or change the birth sex assignment. Female individuals seems to be compliant with their sex, providing that virilisation does not occur. In Italy, the disorder seems to be more prevalent in the Southern regions and shows genetic heterogeneity.

Clinical, endocrine, and molecular findings in 17beta-hydroxysteroid dehydrogenase type 3 deficiency

The 17beta-hydroxysteroid dehydrogenases (17betaHSD) gene family comprises different enzymes involved in the biosynthesis of active steroid hormones. The 17betaHSD type 3 (17betaHSD3) isoenzyme catalyzes the reductive conversion of the inactive C19-steroid, Delta4-androstenedione (Delta4- A), into the biologically active androgen, testosterone (T), in the Leydig cells of the testis. It is encoded by the 17beta-hydroxysteroid dehydrogenase type 3 (HSD17B3) gene, which maps to chromosome 9q22. Mutations in the HSD17B3 gene are associated with a rare form of 46,XY disorder of sex development referred to as 17betaHSD3 deficiency (or as 17-ketosteroid reductase deficiency), due to impaired testicular conversion of Delta4-A into T. 46,XY patients with 17betaHSD3 deficiency are usually classified as female at birth, raised as such, but develop secondary male features at puberty. Diagnosis, and consequently early treatment, is difficult because clinical signs from birth until puberty may be mild or absent. Biochemical diagnosis of 17betaHSD3 deficiency requires measurement of serum T/Delta4-A ratio after hCG stimulation test in pre-pubertal subjects, while baseline values seem to be informative in early infancy and adolescence. However, low basal T/Delta4-A ratio is not specific for 17betaHSD3 deficiency, being sometimes also found in patients with other defects in T synthesis or with Leydig cells hypoplasia. Mutational analysis of the 17HSDB3 gene is useful in confirming the clinical diagnosis of 17betaHSD3 deficiency. This review describes clinical findings, diagnosis, and molecular basis of this rare disease.

17beta-hydroxysteroid dehydrogenase-3 deficiency: a rare endocrine cause of male-to-female sex reversal

Deficiency of 17beta-hydroxysteroid dehydrogenase type 3 (17beta-HSD3), due to mutations in the gene encoding the enzyme, results in a rare autosomal recessive form of male-to-female sex reversal. Mutated genes encode an abnormal enzyme with absent or reduced ability to convert Delta4-androstenedione to testosterone in the testis. Affected individuals are genetically males who developed internal male Wolffian structures but female external genitalia. Such individuals are usually raised as females and diagnosis is made at puberty, when they show virilization. Correct diagnosis is mandatory to optimize treatment and follow-up. In the present paper we report the clinical history, endocrine evaluation and molecular genetics of a prepubertal girl affected by 17beta-HSD3 deficiency, in whom an erroneous diagnosis of androgen insensitivity syndrome was made. The clinical, endocrine and genetic features of 17beta-HSD3 deficiency are also reviewed.

Gender change in 46,XY persons with 5alpha-reductase-2 deficiency and 17beta-hydroxysteroid dehydrogenase-3 deficiency

Individuals with 5alpha-reductase-2 deficiency (5alpha-RD-2) and 17beta-hydroxysteroid dehydrogenase-3 deficiency (17beta-HSD-3) are often raised as girls. Over the past number of years, this policy has been challenged because many individuals with these conditions develop a male gender identity and make a gender role change after puberty. The findings also raised doubts regarding the hypothesis that children are psychosexually neutral at birth and emphasized the potential role of prenatal brain exposure to androgens in gender development. If prenatal exposure to androgens is a major contributor to gender identity development, one would expect that all, or nearly all, affected individuals, even when raised as girls, would develop a male gender identity and make a gender role switch later in life. However, an estimation of the prevalence of gender role changes, based on the current literature, shows that gender role changes occur frequently, but not invariably. Gender role changes were reported in 56-63% of cases with 5alpha-RD-2 and 39-64% of cases with 17beta-HSD-3 who were raised as girls. The changes were usually made in adolescence and early adulthood. In these two syndromes, the degree of external genital masculinization at birth does not seem to be related to gender role changes in a systematic way.

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.

A clinician looks at androgen resistance

Androgen resistance in genetic males occurs when gonadotropins and testosterone are normal, but the physiological androgen response in androgen target organs is absent or decreased. In androgen-dependent target tissues two main defects may be found: 1) defective testosterone metabolism (5 alpha-reductase type 2 deficiency) and 2) anomalies in androgen receptors (androgen insensitivity syndrome (AIS)). The clinical manifestations of these defects vary from subjects with female external genitalia to subjects with mild forms of impaired masculinization. In particular, in the complete form of AIS (CAIS) the phenotype is feminine, and in the partial form (PAIS) the external genitalia are ambiguous with an extremely variable phenotype. The diagnosis requires clinical, hormonal, genetic, and molecular investigation for appropriate gender assignation and treatment. In AIS, cloning of androgen receptor cDNA using the polymerase chain reaction, denaturing gradient gel electrophoresis, and nucleotide sequencing have enabled a variety of molecular defects in the androgen receptor to be identified. The complexity of phenotypic presentation of AIS probably reflects the heterogeneity of androgen receptor gene mutations, but to date a relationship between genotype/phenotype has been difficult to establish, with the same point mutation reported to be associated with different phenotypic expressions. Other factors must therefore also contribute to the clinical presentation of AIS, although none have yet been identified. Establishing the functional consequences of androgen receptor mutations in vitro systems and correlating them with clinical presentation may ultimately provide an explanation for the variable clinical presentation of AIS and perhaps enable prediction of the response to androgen therapy in infants with PAIS.

Disorders of sexual development

Over the past 6 years, the structures of four key genes involved in sexual differentiation have been identified (see Figure 2). Mutations within these genes have been demonstrated to cause a significant percentage of the disorders of sexual differentiation described in this chapter. It should be noted, however, that there are significant numbers of patients with these disorders in whom no mutation in any of these genes has yet been characterized. It is probable that further genes involved in sexual differentiation will be identified and shown to be the cause of a number of these diseases.

Male hypogonadism with gynecomastia caused by late-onset deficiency of testicular 17-ketosteroid reductase

BACKGROUND

17-Ketosteroid reductase deficiency results in male pseudohermaphroditism because conversion of the weak androgen androstenedione to the more potent androgen testosterone is impaired. If a late-onset form exists, hypogonadism and gynecomastia caused by decreased testosterone production and increased estrogen production, respectively, would be expected as the major clinical manifestations in men.

METHODS

We studied 48 male subjects, ranging from 14 to 26 years of age, who had idiopathic pubertal gynecomastia. Serum concentrations of gonadal and adrenal steroid hormones were measured before and after the administration of corticotropin and after the combined administration of chorionic gonadotropin and dexamethasone for three days.

RESULTS

We identified three unrelated subjects (ages, 16, 17, and 26 years) with results indicative of a partial deficiency of testicular 17-ketosteroid reductase. The three subjects had gynecomastia as well as decreased libido and impotence. Their mean (+/- SD) base-line serum androstenedione and estrone concentrations were elevated as compared with the levels in the 45 subjects without this enzyme deficiency (androstenedione, 380 +/- 70 vs. 110 +/- 70 ng per deciliter [13 +/- 2 vs. 4 +/- 2 nmol per liter]; estrone, 138 +/- 12 vs. 46 +/- 9 pg per milliliter [511 +/- 44 vs. 170 +/- 33 pmol per liter]). After the administration of chorionic gonadotropin, the mean serum androstenedione concentration in these three subjects was 910 +/- 48 ng per deciliter (32 +/- 2 nmol per liter) and the mean serum estrone concentration was 260 +/- 16 pg per milliliter (962 +/- 59 pmol per liter). The mean serum testosterone concentration at base line was 210 +/- 80 ng per deciliter (7.4 +/- 2.8 nmol per liter) in the 3 subjects, as compared with a value of 410 +/- 12 ng per deciliter (14.4 +/- 0.42 nmol per liter) in the 45 other subjects, and it did not increase in response to the administration of chorionic gonadotropin. The concentrations of androstenedione and estrone in spermatic venous serum were 19 times higher and 73 times higher, respectively, than in normal men. The serum concentrations of follicle-stimulating hormone and luteinizing hormone in these three subjects were inappropriately low, suggesting the presence of hypogonadotropic hypogonadism.

CONCLUSIONS

A late-onset form of testicular 17-ketosteroid reductase deficiency can cause gynecomastia and hypogonadism in men.

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.

Prepubertal male pseudohermaphroditism due to 17-ketosteroid reductase deficiency: diagnostic value of a hCG test and lack of HLA association

Most patients with male pseudohermaphroditism (MPH) due to 17-ketosteroid reductase (17-KSR) deficiency were diagnosed at or after puberty when significant virilization occurred. We report 2 prepubertal sibs (Case 1, 4 yr and Case 2, 10 yr) unambiguously raised as females, with clitoral enlargement, separate urethral and vaginal orifices and gonads palpable at the inguinal canal bilaterally. Basal serum LH, FSH, 17-hydroxyprogesterone, testosterone (T), dihydrotestosterone and dehydroepiandrosterone (DHEA) were normal for age. delta 4-Androstenedione (delta 4-A) was slightly elevated in Case 2 but nondiagnostic. Steroid measurements after human chorionic gonadotropin (hCG) stimulation were compared with those of boys with male external genitalia submitted to the same hCG protocol: peak T was subnormal (Case 1, 80, Case 2, 91, vs normal 329 +/- 129 ng/dl, mean +/- 1SD), peak delta 4-A elevated (Case 1, 477, Case 2, 264, vs normal 44 +/- 26 ng/dl) resulting in an abnormally elevated delta 4-A/T ratio (Case 1, 6.0, Case 2, 2.9, vs normal 0.12 +/- 0.09) and establishing the diagnosis of 17-KSR deficiency. This diagnosis was confirmed in vitro by minimal T production when testicular tissue of both patients was incubated with tritiated delta 4-A. The 2 sibs did not share a single haplotype for the HLA complex indicating lack of association between HLA and the locus of the gene for 17-KSR. In conclusion, in 2 sibs with MPH the subnormal T and elevated delta 4-A response to the hCG test indicated the diagnosis of 17-KSR deficiency followed by orchiectomy to avoid later virilization at puberty.

The coexistence of male pseudohermaphrodites with 17-ketosteroid reductase deficiency and 5 alpha-reductase deficiency within a Turkish kindred

Two distinct enzyme defects affecting androgen production and resulting in male pseudohermaphroditism were found in a Turkish kindred from a small isolated village in the Taurus mountains of southern Turkey. Pedigree analysis revealed the inter-relationships of 9 male pseudohermaphrodites. Six affected subjects had adequate steroid hormone analysis. Two adult male pseudohermaphrodites had 17-ketosteroid reductase deficiency with elevated concentrations of plasma androstenedione relative to testosterone, and elevated concentrations of urinary androsterone (A) and etiocholanolone (E) relative to tetrahydrocortisol (THF), 5 alpha-tetrahydrocortisol (5 alpha-THF) and tetrahydrocortisone (THE). Four affected males (three adults, one child) had 5 alpha-reductase deficiency (elevated ratios of plasma testosterone/dihydrotestosterone and urinary 5 beta/5 alpha C19 and C21 steroid metabolites). The homozygous state for both enzyme deficiencies was not demonstrable in the same affected subject, suggesting that the enzyme deficiencies are segregating separately within this kindred. Whether the mutant genes are segregating on allelic chromosomes or other autosomes cannot be determined from this study.

Incomplete masculinization due to a deficiency of 17 beta-hydroxysteroid dehydrogenase: comparison of prepubertal and peripubertal siblings

Incomplete masculinization due to a deficiency of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) was investigated in siblings aged 4 years (Case 1) and 12 years (Case 2). Diagnosis was based on increased ratios of androstenedione (A) to testosterone (T) in blood, and impaired reduction of A to T by 17 beta-HSD in vitro in the testes. Impairment was total in Case 2 but partial in Case 1. Case 2 also showed deficient conversion of dehydroepiandrosterone (DHA) to androstenediol and of oestrone to oestradiol by 17 beta-HSD which were normal in Case 1. Oxidation of T to A by 17 beta-HSD and conversion of 17 alpha-hydroxyprogesterone to A by 17,20 desmolase were normal in the testes of both siblings. 3 beta-HSD conversion of DHA to A was normal in Case 1, but markedly increased in Case 2. In contrast to testicular findings, 17 beta-HSD reduction of A to T in genital skin fibroblasts from Case 2 was normal and diagnosis would not have been possible from studies of measurements of this enzyme in skin. The severity of the testicular 17 beta-HSD deficiency in the peripubertal compared with the prepubertal sibling suggests either considerable intra-familial variation in the extent of the enzyme defect or that puberty may aggravate this disorder. The normal reductive action of 17 beta-HSD in skin, despite impaired action in testes, suggests involvement of more than one iso-enzyme.