Gary D. Berkovitz

The role of the sex-determining region of the Y chromosome (SRY) in the etiology of 46,XX true hermaphroditism

SummaryThe syndrome of 46,XX true hermaphroditism is a clinical condition in which both ovarian and testicular tissue are found in one individual. Both Mullerian and Wolffian structures are usually present, and external genitalia are often ambiguous. Two alternative mechanisms have been proposed to explain the development of testicular tissue in these subjects: (1) translocation of chromosomal material encoding the testicular determination factor (TDF) from the Y to the X chromosome or to an autosome, or (2) an autosomal dominant mutation that permits testicular determination in the absence of TDF. We have investigated five subjects with 46,XX true hermaphroditism. Four individuals had a normal 46,XX karyotype; one subject (307) had an apparent terminal deletion of the short arm of one X chromosome. Genomic DNA was isolated from these individuals and subjected to Southern blot analysis. Only subject 307 had Y chromosomal sequences that included the pseudoautosomal boundary, SRY (sex-determining region of Y), ZFY (Y gene encoding a zinc finger protein), and DXYS5 (an anonymous locus on the distal short arm of Y) but lacked sequences for DYZ5 (proximal short arm of Y) and for the long arm probes DYZ1 and DYZ2. The genomic DNA of the other four subjects lacked detectable Y chromosomal sequences when assayed either by Southern blotting or after polymerase chain reaction amplification. Our data demonstrate that 46,XX true hermaphroditism is a genetically heterogeneous condition, some subjects having TDF sequences but most not. The 46,XX subjects without SRY may have a mutation of an autosomal gene that permits testicular determination in the absence of TDF.

Congenital micropenis: Long-term medical, surgical and psychosexual follow-up of individuals raised male or female

Objectives: to document long-term medical, surgical and psychosexual outcome of individuals with congenital micropenis (13 males, 5 females). Methods: Physical measurements from childhood were collected retrospectively from medical records and at adulthood by physical examination. An adult psychosexual assessment was conducted with a written questionnaire and oral discussion. Results: Adult penile length was below the normal mean in all men. Three women had vaginoplasty resulting in normal length. All men reported good or fair erections but 50% were dissatisfied with their genitalia. Dissatisfaction with body image resulted from having a small penis (66%), inadequate body hair (50%), gynecomastia (33%) and youthful appearance (33%). Ten men were heterosexual, 1 homosexual and 2 bisexual. Among women, 4 (80%) were dissatisfied with their genitalia. Three women reported average libido with orgasm and were also heterosexual. Two women had no sexual interest or experience. Finally, males were masculine and females feminine in their gender-role identity, and both groups were satisfied with their sex of rearing. Conclusions: Regarding choice of gender, male sex of rearing can result in satisfactory genito-sexual function. Female gender can also result in success, however it requires extensive feminizing surgery.

Familial gynecomastia with increased extraglandular aromatization of plasma carbon19-steroids.

We evaluated a family in which gynecomastia occurred in five males in two generations. In each affected subject, gynecomastia and male sexual maturation began at an early age. The ratio of the concentration of plasma estradiol-17 beta to that of plasma testosterone was elevated in each affected subject. In the three siblings with gynecomastia, the transfer constant of conversion of androstenedione to estrone (i.e., the fraction of plasma androstenedione that was converted to estrone as measured in the urine) was 10 times that of normal persons. The transfer constant of conversion of testosterone to estradiol-17 beta in the one subject studied also was 8-10 times that of normal men, whereas the transfer constants of conversion of estrone to estradiol-17 beta and of estradiol-17 beta to estrone were normal. Despite the elevation in extraglandular aromatase activity, there was a normal response of the hypothalamic-pituitary axis to provocative stimuli. This is the second documentation of gynecomastia that is associated with increased extraglandular aromatase activity, and the first time that the defect was found to be familial with a probable X-linked (or autosomal dominant, sex limited) mode of inheritance.

46,XX sex reversal with partial duplication of chromosome arm 22q

We present a case of 46,XX sex reversal in the absence of SRY but with partial duplication of chromosome 22q. The subject had multiple congenital anomalies but nearly complete masculinization of the external genitalia. Our case along with a previous case supports the existence of a gene on chromosome 22q that can trigger testis determination in the absence of SRY. We proposed that overexpression of the SOX10 gene at 22q13 might be the cause of sex reversal. We investigated 13 additional subjects with SRY‐negative 46,XX sex reversal for microduplication of chromosome arm 22q in the region of SOX10 gene, but could not find evidence for it.

Androgen Receptor Levels and 5α-Reductase Activities in Preputial Skin and Chordee Tissue of Boys with Isolated Hypospadias

The cause of hypospadias in the majority of patients is unknown. We examined the hypothesis that hypospadias might be explained by androgen receptor abnormalities in the atretic spongiosal tissue commonly known as chordee. We studied 10 patients with relatively severe hypospadias but with a predominantly male phenotype and no readily ascertained explanation for the defect, including no evidence of an abnormality in testosterone biosynthesis. Eight subjects had midshaft hypospadias and 2 had a penoscrotal meatus. All 10 patients had severe chordee. Serum concentrations of testosterone, and luteinizing and follicle-stimulating hormones were measured before human chorionic gonadotropin stimulation and a serum testosterone level was determined 24 hours after the last dose of a 5-day human chorionic gonadotropin stimulation (3,000 units per M.2 per day). Androgen receptor content and binding affinity were assayed in fibroblasts cultured from preputial skin and chordee tissue of patients and foreskin from normal male neonates. With the endogenous ligand dihydrotestosterone the mean number (maximum binding capacity) of androgen receptors was 1,013 fmol. per mg. deoxyribonucleic acid in preputial skin and 833 fmol. per mg. deoxyribonucleic acid in chordee tissue of patients, and 627 fmol. per mg. deoxyribonucleic acid in the foreskin of controls. With the nonmetabolizable, synthetic androgen methyltrienolone (R1881) the mean maximum binding capacity was 1,004, 722 and 758 fmol. per mg. deoxyribonucleic acid, respectively. Dihydrotestosterone receptor affinity (dissociation constant) was similar in preputial skin (0.20 nM.) and chordee tissue (0.21 nM.) from patients, and foreskin (0.29 nM.) from controls. Androgen receptor binding affinity of R1881 also was similar (0.30, 0.24 and 0.21 nM., respectively). Furthermore, the 5 alpha-reductase activity of preputial skin and chordee tissue of patients with hypospadias was similar to that of foreskin from normal neonates. In conclusion, isolated hypospadias in these subjects was not associated with androgen insensitivity of the spongiosal tissues on the basis of either decreased androgen receptor binding affinity, receptor number or conversion of testosterone to dihydrotestosterone.

Elevation of Serum Gonadotropins Establishes the Diagnosis of Anorchism in Prepubertal Boys with Bilateral Cryptorchidism

Of more than 500 boys with bilateral cryptorchidism who presented during a 10-year period 28 prepubertal patients less than 11 years old who had no palpable testes after human chorionic gonadotropin therapy were studied to assess the ability of serum gonadotropin levels to identify patients with anorchism. Of the boys 21 had a normal testosterone response to human chorionic gonadotropin therapy and all of them had testes at exploration. The serum luteinizing hormone levels ranged from 2 to 6 mIU per ml., with a mean of 3.7 mIU per ml., and the serum follicle-stimulating hormone levels ranged from 1.6 to 6.2 mIU per ml., with a mean of 3.7 mIU per ml. Seven patients showed no testosterone response to human chorionic gonadotropin and all but 1 underwent exploration, at which time no testes were found. Of these 7 patients 6 had elevated gonadotropin levels that averaged 3 standard deviations above the mean. For comparison, 2 pubertal patients with nonpalpable gonads and 3 castrated prepubertal boys also were studied. From the study we concluded that in boys with nonpalpable gonads 1) abnormally elevated serum gonadotropin levels before puberty are indicative of anorchism, 2) neither exploration nor human chorionic gonadotropin stimulation tests are essential for diagnosis in these select patients, 3) serum gonadotropin levels alone are not sufficient for a definitive diagnosis after puberty and 4) all boys with normal serum gonadotropin levels must undergo exploration regardless of the outcome of a human chorionic gonadotropin stimulation test.

Endocrine Evaluation of Adults with Mild Hypospadias

The goal of our study was to determine the frequency of endocrine abnormalities in sexually mature men with mild hypospadias. For this purpose we evaluated 16 men 22 to 52 years old with mild hypospadias. All patients had a urethral meatus distal to the penoscrotal junction. Serum concentrations of luteinizing hormone, follicle-stimulating hormone and testosterone were measured in all subjects. Dihydrotestosterone and testosterone precursors also were determined in men who had abnormally elevated levels of luteinizing hormone. The level of serum luteinizing hormone in patients was significantly higher than that of normal men, whereas the levels of serum follicle-stimulating hormone and testosterone were similar to those of normal subjects. Of the 16 men with mild hypospadias 3 had abnormally elevated levels of gonadotropins: 2 had primary gonadal dysfunction (elevated luteinizing hormone and follicle-stimulating hormone with low or normal testosterone) and 1 had hormonal evidence of partial androgen insensitivity (elevated luteinizing hormone, normal follicle-stimulating hormone with high normal testosterone and dihydrotestosterone). These patients are rather unique, since they did not have other compromising factors to account for the gonadal failure. In summary, our data demonstrated the presence of endocrine dysfunction in men with mild hypospadias.

Evaluation of Boys with Marked Breast Development at Puberty

During the 10-year period from 1979 to 1988 we evaluated 60 boys who were more than 9 years old and who had significant breast development (greater than 4 cm in diameter) around the time of puberty. An endocrine abnormality was identified in seven subjects. The pathology included Klinefelters syndrome; 46, XX maleness; primary testicular failure; partial androgen insensitivity; fibrolamellar hepatocarcinoma; and increased aromatase activity. Eight of the remaining 53 subjects had underlying medical problems, five of them having neurologic disorders. The 45 remaining subjects were considered to have significant idiopathic gynecomastia, a condition sometimes referred to as macromastia. These boys tended to be both taller and heavier than average, the mean Z score for height being 1.4 SDs above the mean and the mean weight score being 2.7 SDs above the mean. This study underscores the observation that pathologic causes of marked pubertal gynecomastia are unusual. However, the potential for significant health problems among boys with marked breast development supports the need for an endocrine evaluation of all affected subjects. Our data also indicate that boys with marked idiopathic breast development have greater body mass than other boys of similar age. This may contribute in part to the greater breast development in these subjects.

Aromatase activity in microsomal preparations of human genital skin fibroblasts: Influence of glucocorticoids

Skin is an important site of estrogen production in men. Although the aromatase complex in these cells appears to be similar to that of other human cells, the regulation of aromatase by glucocorticoids in cultured human skin fibroblasts is unique. We examined aromatase activity in microsomal-enriched fractions of cultured human skin fibroblasts in order to characterize better the factors that regulate the aromatase in these cells. The optimum pH for aromatase activity in microsomal preparations ranged between 7.0 and 7.5. When androstenedione was the substrate, the mean Vmax was 0.58 pmol/mg protein/h (range: 0.09-1.26 pmol/mg protein/h) and the mean Km was 27 nM (range: 9-50 nM). When aromatase activity was determined as a function of NADPH concentration, the mean Vmax was 0.39 pmol/mg protein/h (range 0.11-0.82 pmol/mg protein/h) and the mean Km was 180 microM (range: 86-300 microM). For skin fibroblasts exposed to DEX, aromatase activity in isolated microsomes and intact cells was stimulated demonstrating a typical time course with peak levels at 14h and a decline toward baseline with prolonged (48-60 h) exposure. Cytosol from DEX-stimulated cells did not stimulate the aromatase activity in microsomal-enriched preparations from untreated cells. In addition, cytosol from cells incubated with DEX for a prolonged period (60 h) did not inhibit the higher aromatase activity of microsomes from cells incubated with DEX for only 14 h. We previously demonstrated that skin fibroblasts incubated with DEX and CHX produced a superinduction phenomenon for aromatase activity. This superinduction of enzyme activity also occurred in the microsomal-enriched fraction and was unaffected by the cytosol of these cells. These studies exclude the possibility that the unique effects of DEX on the aromatase in human skin fibroblasts are due to the production of either inhibitory or stimulatory soluble factors within cytosol.

Madelung-like deformity in pseudohypoparathyroidism type 1b.

CONTEXT Pseudohypoparathyroidism (PHP) types 1a and 1b are distinguished by clinical, biochemical, and molecular features. We report extended kindred with PHP 1b in which many affected members also had growth plate defects, including brachydactyly and a Madelung-like deformity. DESIGN Analyses included clinical examination, assessment of mineral metabolism, thyroid function, skeletal radiography, and analysis of the GNAS and STX16 genes. SETTING Patients were studied in an academic medical center. RESULTS We studied 37 members of a family in which PHP 1b occurred in 23 individuals. Ten of 17 affected patients who were examined had brachydactyly E, including two subjects with Madelung-like defects. Five of 16 subjects had subclinical hypothyroidism; no subject showed sc ossification or short stature. None of the unaffected members had brachydactyly or an elevated serum level of PTH or TSH. Levels of immunoactive erythrocyte Gα(s) were normal in two affected subjects tested. Linkage analysis indicated linkage between PTH resistance and the GNAS gene locus; however, no mutations were identified in GNAS exons 1-13. Methylation analysis of genomic DNA from affected subjects showed loss of maternal epigenotype in exon 1A with normal methylation of the differentially methylated regions for XLGαs and NESP55, and PCR demonstrated heterozygosity for a 3.0-kb deletion in the STX16 gene. CONCLUSION The segregation of brachydactyly with PHP 1b in this family indicates that an imprinting defect in GNAS can lead to growth plate defects, including brachydactyly and Madelung deformity. These features suggest that GNAS signaling plays a more extensive role in chondrocyte maturation than previously thought.