A heterozygous mutation in the desert hedgehog gene in patients with mixed gonadal dysgenesis

Aetiology of mixed gonadal dysgenesis (MGD) has not been completely elucidated. Molecular analyses have failed to demonstrate the presence of mutations in sex-determining region on Y chromosome (SRY); it has been suggested that these individuals may bear mutations in other genes involved in the testis-determining pathway. Desert hedgehog's (DHH) importance regarding male sex differentiation has been demonstrated in various studies we describe here, for the first time, two cases of MGD in which a monoallelic single base deletion in DHH is associated with the disorder. Genomic DNA was isolated from paraffin-embedded gonad tissue from 10 unrelated patients with MGD and three controls; in addition to, DNA from peripheral blood leukocytes in 100 controls. Coding sequence abnormalities in DHH were assessed by exon-specific PCR, single-stranded conformation polymorphism (SSCP) and direct sequencing. In two patients, a heterozygous 1086delG in exon 3 was found. Comparing previously described mutations in DHH to the one observed in this study, we can affirm that the phenotypic spectrum of patients with gonadal dysgenesis due to mutations in DHH is variable. This study continues to demonstrate the importance that DHH has in mammalian male sexual differentiation, providing extended evidence that DHH constitutes a key gene in gonadal differentiation.

CRH-stimulation of cyclic adenosine 5'-monophosphate pathway is partially inhibited by the coexpression of CRH-R1 and CRH-R2alpha

Corticotropin-releasing hormone (CRH) is one of the major proteins responsible for brain stress regulation. Two well-known receptors have been described: type 1 and type 2alpha, both members of the receptor superfamily of G protein-coupled receptors (GPCR). We investigated receptor regulation when both CRH receptor subtypes are coexpressed in the same mammalian cell line. When both types of receptors are coexpressed, cAMP second messenger production is partially inhibited compared to when receptors are expressed separately. However, neither binding kinetics nor internalization rates are modified by coexpression of these receptors. To our knowledge this is the first demonstration of receptor interaction that results in the modification of CRH-mediated signal transduction pathway. Because CRH-R1 and CRH-R2alpha have overlapping mRNA expression patterns in the brain, these receptors may be coexpressed in neurons, suggesting that receptor interaction may play an important role in the effect evoked by CRH, contributing to the complexity of differential coupling of the CRH receptors in different endocrine and stress behavior responses.

No evidence of mutations in the P450 aromatase gene in patients with polycystic ovary syndrome

BACKGROUND

Etiology and inheritance pattern in polycystic ovary syndrome (PCOS) remain uncertain. Granulosa cells from follicles of women with PCOS have little, if any, aromatase (encoded by the CYP19 gene) activity; follicles contain low levels of estradiol, P450arom mRNA and aromatase stimulating bioactivity. Mice with targeted disruption of the CYP19 gene present cystic follicles. It has been proposed that chronic exposure to high levels of LH, because of aromatase deficiency, determines the development of ovarian cysts. Herein, we investigated if mutations in the CYP19 gene and/or its ovary promoter are causal in patients with PCOS.

METHODS

Twenty-five patients with PCOS and 50 control women were studied. PCR analysis of genomic DNA and complete sequence of all exons of the aromatase gene and its ovary promoter were performed.

RESULTS

No heterozygous or homozygous mutant alleles were present in any of the patients studied.

CONCLUSIONS

In the population studied, mutations of the P450arom gene or its promoter are not the cause of PCOS. However, these findings do not preclude the possible importance of an aromatase disorder in PCOS etiology. Variations in aromatase complex function could play a role in PCOS etiology, but the determinants of such variations might be located in other genes.

Regulation of follicle-stimulating and luteinizing hormone receptor signaling by

Follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) belong to the super-family of G protein-coupled receptors (GPCR); GPCRs are negatively regulated by RGS ("regulators of G protein signaling") proteins. In this study we evaluated the effects of RGS3 and RGS10 on FSHR and LHR ligand binding and effector coupling. FSHR and LHR ligand binding were unchanged in the presence of RGS3 or RGS10. However, signaling by FSHR and LHR was diminished by RGS3 but not by RGS10. This constitutes the first demonstration of an interaction between RGS proteins and LH and FSH signaling pathways and identifies a mechanism for negative regulation of RGS3 on FSHR and LHR signaling.

Polymorphic changes in the KAL1 gene: not all of them should be classified as polymorphisms

The KAL1 gene has a closely related nonfunctional pseudogene on the Y chromosome; a high degree of X-Y sequence similarity is observed. Some individuals present a T to C substitution at position 1833 (exon 12). Because this nucleotide differs in the X (thymine) and in the Y (cytosine) chromosome, we investigated if this was truly a polymorphism, or if in some cases the Y sequence had been amplified. The complete sequence of exon 12 of KAL1 was analyzed in 11 Kallmann Syndrome (KS) males, in 50 normal males, in 50 normal females, and in 16 patients with Ullrich-Turner Syndrome (UTS). Nucleotide 1833 was found in a heterozygous or a homozygous state in KS, normal males and normal females; UTS patients were always homozygous. Of the 61 males, 17 were heterozygous, while 11 were TT and 33 were CC. With these observations we can not assure whether these patients present a "real" polymorphism. Besides, all males were heterozygous in nucleotides 1678, 1694, 1699, 1708 and 1825, whilst females were homozygous; and in these positions, KAL1 also differs from its pseudogene. These results indicate that we are identifying the X and the Y nucleotide and these variants are not polymorphisms. Sequence variations may be pseudogene products rather than true polymorphisms, so we should always determine if the position where the variation is located differs between KAL1 and its pseudogene, because it has been suggested that the presence of various polymorphisms in affected individuals could be the cause of KS.

Mutations in the desert hedgehog (DHH) gene in patients with 46,XY complete pure gonadal dysgenesis

Mutations of SRY are the cause of complete pure gonadal dysgenesis (PGD) in 10-15% of patients. In the remaining individuals, it has been suggested that mutations in other genes involved in the testis-determining pathway could be causative. We describe the first report in which three cases of 46,XY complete PGD are attributed to mutations of the Desert hedgehog (DHH) gene. DHH was sequenced using genomic DNA from paraffin-embedded gonadal tissue from six patients with complete 46,XY PGD. Mutations were found in three patients: a homozygous mutation in exon 2, responsible for a L162P, and a homozygous 1086delG in exon 3. Mutated individuals displayed 46,XY complete PGD, differentiating from the only previously described patient with a homozygous DHH mutation, who exhibited a partial form of PGD with polyneuropathy, suggesting that localization of mutations influence phenotypic expression. This constitutes the first report where mutations of DHH are associated with the presence of 46,XY complete PGD, demonstrating that the genetic origin of this entity is heterogeneous and that disorders in other genes, different from SRY, involved in the testis-determining pathway are implicated in abnormal testicular differentiation in humans. These data extend previous reports demonstrating DHH is a key gene in gonadal differentiation.

Basal and gonadotropin-releasing hormone-releasable serum follicle-stimulating hormone charge isoform distribution and in vitro biological-to-immunological ratio in male puberty

Follicle-stimulating hormone is synthesized and secreted as a mixture of heterogeneous isoforms that differ from each other in carbohydrate structure, biological potency, and plasma half-life. The relative abundance of the FSH isoforms will depend on the endocrine status of the donor at the time of sample collection. In the present study, we attempted to define the impact of the changing endocrine milieu characteristic of male puberty on the charge heterogeneity and plasma half-life of the serum FSH isoforms released under endogenous and exogenous GnRH drives, and examined whether such a varying hormone milieu modifies the capability of the circulating hormone to trigger intracellular signal transduction at the human FSH receptor level. Forty healthy male subjects at Tanner stages (Ts) 1 to 5 were sampled at 10 min intervals for 10 h. Serum from successive samples collected across 2-4 h intervals containing FSH released under basal, low-dose (10 microg), and high-dose (90 microg) exogenous GnRH-stimulated conditions was subjected to preparative chromatofocusing and tested for bioactivity employing a homologous cell in vitro bioassay system. Deconvolution analysis was applied to estimate the apparent endogenous FSH plasma half-life in samples obtained after administration of low-dose exogenous GnRH. Under all conditions studied, serum FSH charge isoforms were distributed along a pH range of 7.0 to less than 3.0. Comparisons across the different Tanner stages revealed a significant and selective increase in the ratio of FSH isoforms with elution pH values <4.50 relative to those with values >/=4.50 at Ts-2. At Ts-3, this ratio returned to that present at Ts-1, to decline thereafter during the ensuing pubertal stages. Serum bioactive FSH concentrations progressively increased (from 3.72 +/- 1.3 to 16.2 +/- 5.3 IU/L) throughout puberty, and in all conditions bioactive FSH concentrations exceeded those detected by a specific radioimmunoassay. The biological to immunological (B:I) FSH ratio at baseline was significantly (p < 0.05) lower at Ts-1 and Ts-2 (1.33 +/- 0.30 and 1.62 +/- 0.34, respectively) than at more advanced stages of pubertal development (2.28 +/- 0.20, 2.96 +/- 0.38, and 2.77 +/- 0.63 at Ts-3-, 4-, and -5, respectively) Similar differences were detected in samples containing FSH molecules released after low- and high-dose GnRH administration. The apparent endogenous FSH half-life of the deconvolved GnRH-induced FSH pulses was similar in the five study groups. These results demonstrate that the transition from infancy to sexual maturity in men is accompanied by qualitative changes in the circulating FSH isoform mixture. Although the changes in FSH glycosylation occurring throughout puberty are not of sufficient magnitude to alter the survival of the gonadotropin in circulation, they allow preferential secretion of bioactive FSH. The enrichment of the circulating mix of FSH isoforms with highly bioactive variants throughout spontaneous puberty may potentially favor the development of spermatogenesis and acquisition of reproductive competence.

Eight novel mutations of the androgen receptor gene in patients with androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is an X-linked genetic disorder of male sexual differentiation caused by mutations in the androgen receptor (AR) gene. A reliable genotype-phenotype correlation in these patients does not exist as yet. Here we report the molecular studies performed on eight individuals with AIS. Exon-specific polymerase chain reaction (PCR), single-strand conformation polymorphism, and sequencing analyses, were performed in exons 2 to 8 of the AR gene. In one case, total cellular RNA was extracted from genital skin fibroblasts and reverse transcriptase-PCR was performed. Six different point mutations leading to amino acid substitutions (P682T, Q711E, G743E, F827V, H874R, D879Y), one splice-junction mutation (g-->c at +5, exon 6/intron 6), and a missense mutation without amino acid substitution (S888S) were identified. All mutations, including a de novo mutation, were previously undescribed on the steroid binding domain. Of the eight mutations identified, four led to a complete female phenotype (codons 743, 827, 874 and the donor splice site +5), two were detected in phenotypic females with partial virilization (codons 682 and 711), and two were present in phenotypic male subjects with undervirilized external genitalia, thus indicating that all of these sites determine AR functional activity.

46,XX sex reversal

In humans, sexual differentiation is directed by SRY, a master regulatory gene located at the Y chromosome. This gene initiates the male pathway or represses the female pathway by regulating the transcription of downstream genes; however, the precise mechanisms by which SRY acts are largely unknown. Moreover, several genes have recently been implicated in the development of the bipotential gonad even before SRY is expressed. In some individuals, the normal process of sexual differentiation is altered and a sex reversal disorder is observed. These subjects present the chromosomes of one sex but the physical attributes of the other. Over the past years, considerable progress has been achieved in the molecular characterization of these disorders by using a combination of strategies including cell biology, animal models, and by studying patients with these pathologic entities.

Changes in the biological:immunological ratio of basal and GnRH-releasable FSH during the follicular, pre-ovulatory and luteal phases of the human menstrual cycle

BACKGROUND

Significant changes in charge isoform distribution of serum FSH occur throughout the human menstrual cycle. In the present study, we analysed the impact of the changing endocrine milieu characteristic of the menstrual cycle on the capability of basal and gonadotrophin-releasing hormone (GnRH)-releasable FSH to trigger intracellular signal transduction via the human FSH receptor.

METHODS

Seven normal women underwent blood sampling every 10 min for 10 h during the early follicular phase (FP), pre-ovulatory phase (PO) and mid- to late luteal phase (LP) of the menstrual cycle. Serum from successive samples collected across 2 h intervals containing FSH released under baseline and exogenous GnRH-stimulated conditions was tested for bioactivity employing a homologous in-vitro assay.

RESULTS

The biological to immunological (B:I) ratio of basal and GnRH-releasable FSH was significantly (P < 0.05 ) higher at LP (range, 0.83 +/- 0.07 to 1.35 +/- 0.30) than during the FP (0.43 +/- 0.02 to 0.65 +/- 0.04) and PO (0.49 +/- 0.05 to 0.62 +/- 0.06). In all phases, the B:I FSH ratio in baseline samples was similar to those exhibited by samples collected after 10 and 90 microg GnRH administration.

CONCLUSIONS

The selective increase in the capability of the admixture of FSH isoforms circulating during the LP to activate the FSH receptor, apparently represents an additional mechanism through which the anterior pituitary may regulate the maturation of those follicles destined to ovulate during the coming cycle.

A novel homozygous mutation in the second transmembrane domain of the gonadotrophin releasing hormone receptor gene

BACKGROUND AND OBJECTIVE

Mutations in the GnRH receptor (GnRH-R) gene cause hypogonadotrophic hypogonadism. Here, we present the molecular studies of the GnRH-R gene in three families with isolated hypogonadotrophic hypogonadism.

PATIENTS

Three unrelated families, with at least two members diagnosed with isolated hypogonadotrophic hypogonadism were included.

MEASUREMENTS

DNA sequencing was performed after polymerase chain reaction amplification of each of the three exons of the gene.

RESULTS

A novel homozygous missense mutation, at nucleotide 268, turning glutamic acid into lysine, located at the second transmembrane domain of the GnRH-R gene was found in two patients pertaining to one of the families studied. Both parents and an unaffected brother were heterozygous carriers of one mutant allele, an unaffected sister was homozygote wild type. In the other two affected families no mutations were found in the GnRH-R gene.

CONCLUSIONS

This constitutes the first description of an spontaneous mutation located at the second transmembrane domain (Glu90Lys) of the GnRH-R, indicating that the integrity of glutamic acid at this position is crucial for receptor function. Also this report, complementing others, demonstrates that mutations are distributed throughout the GnRH-R gene and that as in the only other homozygous mutation previously described, affected patients present a complete form of hypogonadotrophic hypogonadism. Due to the fact that apparently consanguinity was present in our affected family, we presume that the mutation derived from a common ancestor, by a founder gene effect.

Is there any physiological role for gonadotrophin oligosaccharide heterogeneity in humans? I. Gondatrophins are synthesized and released in multiple molecular forms. A matter of fact

Carbohydrates attached to the protein core of all glycoprotein hormones play an essential role in the function of the molecule, influencing a number of intracellular and extracellular processes. As with other members of the glycoprotein hormone family, pituitary gonadotrophins are not produced as single or unique molecules but rather as arrays of isoforms that differ from each other mainly in the structure of their oligosaccharide attachments. In both experimental animals and in humans, the abundance of the different isoforms varies depending on the endocrine status of the donor present at the time of collection of the tissue or sample. Conditions characterized by an oestrogen-enriched hormonal milieu (eg. the preovulatory phase of the menstrual cycle) promote the formation and secretion of variants with relatively low sialic acid and/or sulphate content, whereas physiological deficiency of this sex steroid (as in the postmenopause) favours the production of highly sialylated, long-lived gonadotrophin variants. When tested individually, less sialylated isoforms exhibit higher receptor-binding and in-vitro biological activity but shorter plasma half-life than their more sialylated counterparts. Both the hormonal regulation and the functional differences among the naturally occurring isoforms strongly suggest that gonadotrophin heterogeneity represents a distinctly different mechanism through which the pituitary gland may regulate the intensity and duration of the gonadotrophic stimulus. Nevertheless, whereas the existence of the alternatively glycosylated variants of gonadotrophins in both the pituitary and in serum is currently without doubt, the physiological role of this phenomenon is still a controversial issue and a matter of debate.

Clinical expression and SRY gene analysis in XY subjects lacking gonadal tissue

In several syndromes genetic males lack gonadal tissue. A range of phenotypes are seen, which varies from complete female external genitalia to anorchic subjects with sexual infantilism. Differences in phenotypic expression depend on the stage at which testes degenerated during intrauterine development. Although most cases of these syndromes are sporadic, several instances of familial recurrence suggest a genetic origin. To help elucidate the source, we performed molecular analysis of the complete SRY gene open reading frame in two subjects with true agonadism and in two with anorchia. Our results add to previous findings indicating that molecular defects in SRY are not readily identified as a cause of these syndromes.

No evidence of mutations in the follicle-stimulating hormone receptor gene in Mexican women with 46,XX pure gonadal dysgenesis

In the ovary FSH is necessary for normal follicular development, binding to its receptor (FSHR) that pertains to the superfamily of G-protein coupled receptors. In the FSHR gene, which consists of 10 exons, an homozygous mutation was reported in six Finnish families with gonadal dysgenesis; whereas two isolated French patients exhibited compound heterozygous mutations. Several groups, however, have searched for FSHR mutations, although in most cases the gene has been studied partially, not finding any genetic abnormalities in German, English, North American or Brazilian women. We performed direct sequencing of all 10 exons of the FSHR gene in seven sporadic patients and two sisters with 46,XX pure gonadal dysgenesis, to investigate the cause of their disorder. No heterozygous or homozygous mutant alleles were present in any of the patients. Although the number of patients evaluated was small, considering all the other previous reports, it seems that except in the Finnish population, the proportion of women with mutations in the encoding region of this gene is very low. Other possibilities for the presence of 46,XX gonadal dysgenesis, such as defects in the regulatory regions of the FSHR gene promoter, in the untranslated regions of exons 1 and 10, and within introns, or the existence of other genes likely to be important for normal ovarian function on the X chromosome or on autosomes, should be considered. In contrast with other studies, we did not find polymorphisms of the FSHR gene, indicating that apparently in Mexicans this gene is not highly polymorphic.

A preponderance of circulating basic isoforms is associated with decreased plasma half-life and biological to immunological ratio of gonadotropin-releasing hormone-releasable luteinizing hormone in obese men

Hormonal abnormalities of the reproductive axis have been described in obesity. In men, extreme obesity is associated with low serum testosterone (T) and high estrogen [estrone and estradiol (E(2))] levels. As changes in the sex steroid milieu may profoundly affect the carbohydrate heterogeneity and thus some of the biological and physicochemical properties of the LH molecule, we analyzed the relative distribution of LH isoforms circulating under baseline conditions (endogenous GnRH drive) as well as the forms discharged by exogenous GnRH stimulation from putative acutely releasable and reserve pituitary pools in overweight men. Secondarily, we determined the impact of the changes in LH terminal glycosylation on the in vitro bioactivity and endogenous half-life of the gonadotropin. Seven obese subjects with body mass indexes ranging from 35.7-45.5 kg/m(2) and seven normal men with body mass indexes from 22.5-24.2 kg/m(2) underwent blood sampling at 10-min intervals for a total of 10 h before and after the iv administration of 10 and 90 microg GnRH. Basally released and exogenous GnRH-stimulated serum LH isoforms were separated by preparative chromatofocusing and identified by RIA of eluent fractions. Serum pools of successive samples collected across 2-h intervals (five serum pools per subject) containing LH released under baseline and exogenous GnRH-stimulated conditions were tested for bioactivity employing a homologous in vitro bioassay. Mean serum T and E(2) levels were significantly lower and higher, respectively, in the obese men than in the control group [serum T, 13.5 +/- 2.4 vs. 19.4 +/- 1.4 nmol/L (mean +/- SEM; P: = 0.01); serum E(2), 0.184 +/- 0.01 vs. 0.153 +/- 0.01 nmol/L (P: < 0.05)]. Mean baseline serum LH levels were similar in obese subjects and normal controls (13.3 +/- 1.3 and 12.2 +/- 1.2 IU/L). Although multiple parameter deconvolution of the exogenous GnRH-induced LH pulses revealed that the magnitude of the pituitary response in terms of secretory burst mass, secretory amplitude, and half-duration of the LH pulses was similar in obese and control subjects, the apparent endogenous half-life of LH was significantly (P: < 0.05) shorter in the obese group (98 +/- 11 min) than in the normal controls (132 +/- 10 min). Under all conditions studied, the relative abundance of basic isoforms (those with pH >/=7.0) was significantly (P: < 0.05) increased in the obese subjects compared with the controls (percentages of LH immunoactivity recovered at pH >/=7.0: obese subjects, 34-57%; normal controls, 22-46%). The biological to immunological ratio of LH released in baseline and low dose (10 microg) GnRH-stimulated conditions were similar in obese subjects and normal controls, whereas LH released by obese subjects in response to the high (90 microg) GnRH dose exhibited significantly lower ratios than those detected in normal individuals (0.62 +/- 0.07 and 0.45 +/- 0.09 vs. 1.01 +/- 0.10 and 0.81 +/- 0.09 for LH released within 10-120 min and 130-240 min after GnRH administration in obese and controls, respectively; P: < 0.05). Collectively, these results indicate that the altered sex steroid hormone milieu characteristic of extreme obesity provokes a selective increase in the release of less acidic LH isoforms, which may potentially modify the intensity and duration of the blood LH signal delivered to the gonad. Altered glycosylation of LH may therefore represent an additional mechanism modulating the hypogonadal state prevailing in morbid obesity.

Partially deleted SRY gene confined to testicular tissue in a 46,XX true hermaphrodite without SRY in leukocytic DNA

True hermaphroditism is an uncommon form of intersexuality in which testicular and ovarian tissue develop in the same individual. Most true hermaphrodites are 46,XX and lack SRY, the testis-determining gene. We describe results of molecular studies performed in a 46,XX true hermaphrodite SRY-negative in DNA from blood leukocytes but SRY-positive in DNA obtained from the testicular portion of the ovotestis. Surprisingly, the SRY identified in gonadal DNA carries a partial deletion at the 5' end of the gene. Our patient is the first case of a naturally occurring deletion within the SRY ORF (with a normal HMG box) and provides a new explanation for the abnormal gonadal development observed in 46,XX true hermaphrodites.

A mutation in the 5' non-high mobility group box region of the SRY gene in patients with Turner syndrome and Y mosaicism

In Ullrich-Turner syndrome (UTS) patients, the presence of a Y-chromosome or Y-derived material has been documented in frequencies ranging from 4-61%. Mutations of SRY (testis-determining gene) constitute the cause of XY sex reversal in approximately 10-15% of females with pure gonadal dysgenesis. Most of these mutations have been described in the HMG (high mobility group) box of the gene, which is the region responsible for DNA binding and bending; however, various mutations outside the HMG box have been reported. We carried out molecular studies of the SRY gene in three patients with a UTS phenotype and bilateral streaks; two presented a 45,X/46,XY mosaic, and the third a Y marker chromosome. In two patients a missense mutation, S18N, was identified in the 5' non-HMG box region in DNA from blood and both streaks; this mutation was not identified in 75 normal males. Sequencing of the DNA region of interest was normal in the father and older brother of patient 1, demonstrating that in this patient the mutation was de novo. A previous report of a 46,XY patient with partial gonadal dysgenesis who presented the same mutation as our patients indicates the probable existence of a hot spot in this region of the SRY gene and strengthens the possibility that all gonadal dysgeneses constitute part of a spectrum of the same disorder. It also demonstrates that a single genetic abnormality can result in a wide range of phenotypic expression.

Identification of missense mutations in the SRD5A2 gene from patients with steroid 5alpha-reductase 2 deficiency

BACKGROUND AND OBJECTIVE

Mutations of the steroid 5alpha-reductase type 2 (SRD5A2) gene in karyotypic males result in a spectrum of external genitalia phenotypes ranging from complete female to nearly complete male. Here we performed genomic DNA analyses from individuals bearing the enzyme deficiency in order to detect the molecular abnormalities.

PATIENTS

Four unrelated 46,XY patients of Mexican origin with ambiguous external genitalia were studied. A fertile, phenotypically normal male was also included.

MEASUREMENTS

Coding sequence abnormalities of the SRD5A2 gene were assessed by exon-specific polymerase chain reaction, single-stranded conformational polymorphism and sequencing analysis.

RESULTS

Five different missense mutations (two of them novel mutations) were identified. Three subjects presented homozygous single base mutations. These were located at exon 2 (G115D), exon 4 (P212R) and exon 5 (R246Q), and such changes have been described previously. The fourth patient was a compound heterozygote who presented two mutations located in exons 1 and 2. We found a hitherto unreported G --> A transition at the second nucleotide of codon 85 in exon 1 (GGC --> GAC), substituting glycine for aspartic acid (G85D). This patient also presented an identical alteration at codon 115 of exon 2, which was carried by his father (G115D). Finally, in another subject who was included originally as a control, we found a C --> A transversion (yet undescribed) at codon 245 in exon 5 (S245Y).

CONCLUSIONS

Four different single base mutations that cause amino acid substitutions were detected in the steroid 5alpha-reductase type 2 gene of affected individuals. One patient and a normal control had two previously undescribed mutations. Although in the latter individual we cannot exclude the possibility that the base change is a genetic polymorphism, the molecular screening of 100 chromosomes suggests strongly that the change at codon 245 does represent a heterozygous mutation. Further studies, including the recreation of the mutations, will help to reveal the biochemical consequences resulting from these changes.

Scant XYqh- testicular cells with normal SRY was enough to differentiate bilateral testes in a 45,X/46,XYqh- patient

OBJECTIVE

It has been established that in 45,X/46,XY individuals predominance of XY or XO gonadal cells determines gonadal differentiation. However, in some cases there is no concordance between the predominance of XY cells and testis differentiation. Here we describe the SRY findings in a patient bearing a 45,X/46,XYqh- karyotype.

STUDY DESIGN

The patient presented two small testes (one with spermatogenesis), a male phenotype, and a predominant 45,X karyotype in leukocytes and gonadal cells. PCRs of SRY, ZFY and Yqh were performed on DNA from leukocytes and from left gonadal tissue. SRY-PCR products were purified and sequenced.

RESULTS

A normal SRY sequence was found in both tissues.

CONCLUSIONS

Despite the predominance of 45,X cells in gonads, some patients in whom SRY is normal can develop testes, probably due to the presence of alternative mechanisms involved in testicular differentiation; however, further gonadal development could be impaired.

Renal abnormalities in patients with Kallmann syndrome

OBJECTIVE

To report experience in patients with Kallmann syndrome (KS) in whom urography was used to establish the type and frequency of renal anomalies associated with the disorder.

PATIENTS AND METHODS

Of 19 patients with KS, 15 had the X-linked recessive form of the disease, whereas the remaining four were sporadic. Each patient underwent intravenous pyelography (IVP) using a non-ionic, low osmolarity contrast medium.

RESULTS

Of the 19 patients with KS, 10 had kidney abnormalities; four presented with unilateral renal agenesis and six had less severe forms of renal abnormality (renal malrotation in four and bilateral dilatation of the calyces and pelves in two). One of the patients with unilateral renal agenesis carried a deletion in KAL, the gene responsible for the X-linked type of KS. Three of the four patients with renal malrotation had a confirmed X-linked recessive form and one carried a point mutation in KAL.

CONCLUSION

These results suggest that kidney abnormalities are more frequent and diverse in patients with KS than previously reported. They also indicate that defects in the KAL gene may contribute to abnormal renal development. However, a review of the literature revealed no close correlation between KAL mutations and kidney anomalies in the X-linked type of disease. Taken together, these data suggest that KAL mutations are not invariably associated with failure of renal development and that additional factors (epigenetic or local) may compensate for defects in the KAL protein.

An atypical contiguous gene syndrome: molecular studies in a family with X-linked Kallmann's syndrome and X-linked ichthyosis

BACKGROUND AND OBJECTIVE

Kallmann's syndrome (KS) is characterized by hypogonadotrophic hypogonadism in association with anosmia or hyposmia. This entity can be associated with X-linked ichthyosis (XLI) in a contiguous gene syndrome. Genetic defects have been demonstrated on the Xp22.3 region explaining the presence of one or both entities in affected individuals. In this report we describe the molecular findings in four patients, pertaining to a three generation family, with KS which was associated with XLI in two of them.

MEASUREMENTS

Enzymatic activity of steroid sulphatase was measured in leucocytes. Polymerase chain reaction of the 14 exons of the Kallmann gene (KAL) and of the 5' and 3' extremes of the steroid sulphatase gene was performed in genomic DNA. PCR products of the 14 exons of the KAL gene were purified and sequenced.

RESULTS

Absence of steroid sulphatase activity and a complete deletion of the STS gene were demonstrated in both patients with XLI. In all subjects, the 14 KAL gene exons amplified in a normal fashion; no mutation was documented after sequencing all exons.

CONCLUSIONS

Although it has been proposed recently that the X-linked form of the disease accounts for the minority of patients with Kallman's syndrome, the pedigree chart of this family demonstrates this inheritance pattern. Various possibilities are mentioned in order to explain the absence of mutation in the KAL gene. The coexistence, in this family, of Kallman's syndrome individuals and patients with Kallman's syndrome and X-linked ichthyosis is discussed.

Contiguous gene syndrome due to deletion of the first three exons of the Kallmann gene and complete deletion of the steroid sulphatase gene

OBJECTIVE

Large terminal or interstitial deletions of the 22.3 region on the short arm of the X chromosome cause contiguous gene syndromes. Kallmann syndrome (hypogonadotrophic hypogonadism with anosmia or hyposmia) associated with X-linked ichthyosis, due to a contiguous gene syndrome, is an uncommon finding. Genetic defects have been demonstrated in the Xp22.3 region, explaining the presence of one or both entities in affected individuals. In this report we describe the molecular findings of a patient with Kallmann syndrome and X-linked ichthyosis.

PATIENT

A 20-year-old subject with hypogonadism, anosmia and generalized ichthyosis was studied endocrinologically, biochemically and molecularly.

MEASUREMENTS

Levels of LH, FSH, GH, testosterone, oestradiol and cortisol were determined basally and after specific stimulation tests. Enzymatic activity of steroid sulphatase was measured in leucocytes. Polymerase chain reaction of the 14 exons of the Kallmann gene and of the 5' and 3' extremes of the steroid sulphatase gene was performed in genomic DNA.

RESULTS

A partial deletion from exon 1 to exon 3 of the Kallmann gene, as well as a complete deletion of the steroid sulphatase gene were observed.

CONCLUSIONS

A patient bearing a contiguous gene syndrome with partial deletion of the Kallmann syndrome gene and complete deletion of the steroid sulphatase gene is described. This is the first time a mutation in the conserved cysteine-rich N-terminal region which corresponds to the whey acidic protein motif of the Kallmann gene has been characterized, thus demonstrating the importance of this specific region for the function of the gene.

Frequency of Y chromosomal material in Mexican patients with Ullrich-Turner syndrome

Cytogenetic studies have shown that 40-60% of patients with Ullrich-Turner syndrome (UTS) are 45,X, whereas the rest have structural aberrations of the X chromosome or mosaicism with a second cell line containing a structurally normal or abnormal X or Y chromosome. However, molecular analysis has demonstrated a higher proportion of mosaicism, and studies in different populations have shown an extremely variable frequency of Y mosaicism of 0-61%. We used Southern blot analysis and polymerase chain reaction (PCR) to detect the presence of Ycen, ZFY, SRY, and Yqh in 50 Mexican patients with UTS and different karyotypes to determine the origin of marker chromosomes and the presence of Y sequences. Our results indicated the origin of the marker chromosome in 1 patient and detected the presence of Y sequences in 4 45,X patients. Taken together, we found a 12% incidence of Y sequences in individuals with UTS. The amount of Y-derived material was variable, making the correlation between phenotype and molecular data difficult. Only 1 patient had a gonadoblastoma. We discuss the presence of Y chromosomes or Y sequences in patients with UTS and compare our frequency with that previously reported.

[Genetic heterogeneity and phenotypic variability in 46,XY sex reversal]

The discordance between the chromosomic and the gonadal-phenotypic sex is known as sex reversal (XX males and XY females). We review the XY pure gonadal dysgenesis characterized by female phenotype, primary amenorrhea and absence of secondary sexual development. Bilateral streak gonads are always present in the complete form of this syndrome, while variable degrees of virilization are found in the partial forms, depending on the severity of the testicular damage. A plausible explanation for this pathology are SRY mutations that interfere with the testicular differentiation. However, only 10-15% of the patients with the complete form show SRY mutations, particularly in the HMG box. The remaining cases are probably due to mutations in different autosomal or X-linked genes which are also involved in the sex differentiation cascade. Recently, it has been shown that mutations in several genes responsible of well known genetic entities as WT1, SOX9, DSS and SF1, result in sex reversal. These findings reveal the genetic heterogeneity and clinical variability of XY sex reversal and provide the basis establishing a hierarchy of genes and their participation in the sex determination pathway.

Two SRY-negative XX male brothers without genital ambiguity

We report a Mexican family in which two sibs were identified as "classic" XX males without genital ambiguities. Molecular studies revealed that both patients were negative for several Y sequences, including SRY. A review of familial cases disclosed that this is the first family where a complete male phenotype was observed in Y-negative XX male non-twin brothers. These data suggest that an inherited loss-of-function mutation, in a gene participating in the sex-determining cascade, can induce normal male sexual differentiation in the absence of SRY.

Codon 89 polymorphism of the human 5alpha-steroid reductase type 2 gene

The existence of a genetic polymorphism within the coding region of the human 5alpha-steroid reductase type 2 (5alpha-SR2) gene is reported in a Mexican population. Genotypic variation was assessed in 100 unrelated, healthy volunteers (50 males; 50 females), using single-stranded conformational polymorphism and direct sequencing analysis. Examination of exon 1 DNAs disclosed the presence of sequences encoding for valine (GTA) or leucine (CTA) at codon 89 of the gene. Of the subjects screened, 45% were homozygous for GTA (89Val), 50% had a heterozygous pattern GTA/CTA (89Val/89Leu) and the remaining 5% were homozygous for CTA (89Leu). These data support the view that the G/C condition at codon 89 of the 5alpha-SR2 gene represents a silent polymorphism which does not alter phenotypical development in the human.

Molecular analysis of the 5 alpha-steroid reductase type 2 gene in a family with deficiency of the enzyme

This report describes the identification of a point mutation in the 5 alpha-reductase type 2 (5 alpha-SR2) gene from a family in which both sibs (6 and 3 years old) have steroid 5 alpha-reductase 2 deficiency. The five exons of the gene were individually amplified by the polymerase chain reaction (PCR) and analysed for single-strand conformation polymorphisms (SSCP) to detect mutations. Direct sequencing of the mutant PCR products demonstrated a single C-->T mutation, within exon 4, changing codon 227 from CGA (Arg) to TGA (premature termination signal). Both patients were homozygous for the mutation, but their parents were heterozygous. These results suggest that the mutation at codon 227 impairs normal 5 alpha-SR2 function, thus leading to the phenotypical expression of this rare enzymatic defect.

Mutations of the 5 alpha-reductase type 2 gene in eight Mexican patients from six different pedigrees with 5 alpha-reductase-2 deficiency

BACKGROUND AND OBJECTIVE

Male pseudohermaphroditism due to 5 alpha-reductase deficiency was originally described in 1974. Recently, 5 alpha-reductase Type 2 gene defects have been found generally to be due to point mutations within the 5 exons of the 5 alpha-reductase-2 gene. In this report, we describe the molecular study of patients with 5 alpha-reductase deficiency.

DESIGN

Previously diagnosed patients with 5 alpha-reductase deficiency were sampled in order to perform molecular studies.

PATIENTS

Eight 5 alpha-reductase deficient individuals from 6 unrelated families.

MEASUREMENTS

Single-strand conformational polymorphism and DNA sequencing were performed after polymerase chain reaction amplification of each of the 5 exons of the gene.

RESULTS

Five different missense mutations were found. In 4 patients a cytosine to guanine substitution was observed at codon 212 in exon 4. Two siblings presented a cytosine to adenine substitution at codon 207 in exon 4. Another patient exhibited a guanine to adenine substitution at codon 34 in exon 1, whilst one individual presented 2 mutations: a guanine to adenine substitution at codon 115 in exon 2 and a guanine to adenine substitution at codon 203 in exon 4 (previously undescribed mutation).

CONCLUSIONS

The presence of the same mutation in 4 patients from 3 families indicates the increased prevalence of this mutation in a particular ethnic group, suggesting a common ancestry for the gene defect in these patients. The existence of hot spots is supported by the mutations in codons 34 and 207 which have also been found in other ethnic groups. Interestingly, the patient who presented 2 different mutations, one of them previously undescribed, was reared as a male and exhibited a more masculine phenotype. Further studies in patients with this and other mutations will be needed to verify genotype-phenotype correlation.

More in-vitro bioactive, shorter-lived human chorionic gonadotrophin charge isoforms increase at the end of the first and during the third trimesters of gestation

In the present study we analysed the dynamics of serum human chorionic gonadotrophin (HCG) charge isoform distribution throughout normal gestation and characterized some of the biological features of the several HCG glycoforms present in the circulation of pregnant women. Blood samples were obtained from normal pregnant women at 10-11, 12-15, 23-26 and 35-38 weeks of gestation. The sera were fractionated by preparative chromatofocusing and the separated HCG isoforms were identified and quantified by radioimmunoassay. The in-vitro biological activity and the plasma half-life of the several circulating HCG isoforms were determined by conventional methods. HCG isoforms became less acidic as pregnancy advanced. In samples taken at 10-11 weeks of gestation, the most acidic HCG molecules (pH < 3.7) comprised > 80% of total HCG recovered after chromatofocusing; this proportion decreased to 58, 60 and 47% in samples taken from weeks 12.1 to 38.4 of gestation. Meanwhile, the relative proportion of less acidic isoforms recovered within pH values 6.49-4.50 increased at the end of the first trimester (12-15 weeks), remained constant until weeks 23-26 and then increased further by the end of the third trimester. Less acidic isoforms had higher in-vitro biological potency per immunological unit than the more acidic analogues. Regardless of the trimester of pregnancy, the plasma half-life of the highly acidic (elution pH < 3.7) isoforms varied from 84.4 to 150 min (116.3 +/- 23.0; mean +/- SD), whereas the corresponding half-life of mid-acidic (pH 4.25-5.31) and low-acidic (pH 5.74-6.50) HCG isoforms ranged from 31.0 to 115.3 (75.5 +/- 20.6) and 15.3 to 58.3 (41.2 +/- 14.3) min respectively (P < 0.01, highly acidic versus mid- and low-acidic analogues and mid-acidic versus least acidic isoforms). The overall data indicate that the human trophoblast is able to regulate the exact intensity, biochemical composition and duration of the gonadotrophic stimulus secreted during the course of normal gestation. They also suggest that the decrease and maintenance of low serum HCG concentrations during the second and third trimesters of gestation may be partially caused by changes in the carbohydrate structure of the HCG molecule.

Low frequency of deletion alleles in patients with steroid 21-hydroxylase deficiency in a Mexican population

Steroid 21-hydroxylase deficiency is caused by mutations in the CYP21 gene. Approximately 95% of mutant alleles are generated by recombination events between the active gene CYP21 and its highly homologous pseudogene, CYP21P. Deletion alleles are generated by unequal crossing over, while point mutations are the result of gene conversion events. Deletions account for 20-25% of the 21-hydroxylase deficiency alleles in most populations studied. We have looked for deletions among 53 unrelated Mexican patients with steroid 21-hydroxylase deficiency and found that deletions represent less than 1% of the disease alleles. These findings suggest that nearly all mutant alleles in our patient population contain point mutations and that the low representation of deletion alleles among clinically diagnosed patients may be due to missing detection of salt wasters, mainly males, who may die during the neonatal period.

Phenotypical expression in XX males correlates with testicular response to exogenous choriogonadotropin in early infancy: does a variable degree of testicular failure determine the degree of genital ambiguity?

The 46,XX male syndrome is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of patients have male external genitalia without ambiguity; however, 10-15% show diverse degrees of hypospadias. Testicular function is normal at birth but deteriorates thereafter. However, it has not been clarified why some cases exhibit genital ambiguity. This study examined 10 affected patients, including 4 prepubertal (< 1 year old) with hypospadias (1 glandular, 1 penile, and 2 penoscrotal). In all subjects, testicular function was evaluated by performing a stimulation with choriogonadotropin. In the postpubertal individuals, basal and poststimuli testosterone were below the reference values. Prepubertal patients had age-appropriate basal test-osterone concentrations. All responded to the choriogonadotropin challenge; however, the most significant response was observed in the patient with the glandular hypospadias, the second highest response was presented by the patient with the penile hypospadias, while both patients with the penoscrotal hypospadias had the poorest responses. These results suggest that the degree of genital ambiguity is correlated with the impairment in testosterone response to choriogonadotropin in early infancy, indicating a defect in testosterone production in XX males with genital ambiguity.

Molecular analysis in true hermaphrodites with different karyotypes and similar phenotypes

True hermaphroditism is characterized by the development of ovarian and testicular tissue in the same individual. Müllerian and Wolffian structures are usually present, and external genitalia are often ambiguous. The most frequent karyotype in these patients is 46,XX or various forms of mosaicism, whereas 46,XX is very rarely found. The phenotype in all these subjects is similar. We studied 10 true hermaphrodites. Six of them had a 46,XX chromosomal complement: 3 had been reared as males and 3 as females. The other 4 patients were mosaics: 3 were 46,XX/46,XY and one had a 46,XX/47,XXY karyotype. One of the 46,XX/46,XY mosaics was reared as a female, whereas the other 3 mosaics were reared as males. The sex of assignment in the 10 patients depended only on labio-scrotal differentiation. Molecular studies in 46,XX subjects documented the absence of Y centromeric sequences in all cases, arguing against hidden mosaicism. One patient presented Yp sequences (ZFY+, SRY+), which contrast with South African black 46,XX true hermaphrodites in whom no Y sequences were found. Molecular analysis in the subjects with mosaicism demonstrated the presence of Y centromeric and Yp sequences confirming the presence of a Y chromosome. Gonadal development, endocrine function, and phenotype in the 10 patients did not correlate with the presence of a Y chromosome or Y-derived sequences in the genome, confirming that true hermaphroditism is a heterogeneous condition.

Clinical traits and molecular findings in 46,XX males

46,XX maleness is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of affected persons have normal external genitalia, but 10-15% show various degrees of hypospadias. Several hypotheses have been proposed to explain the etiology of this constitution: translocation of the testis-determining factor (TDF) from the Y to the X chromosome, mutation in an autosomal or X chromosomal gene which permits testicular determination in the absence of TDF, and undetected mosaicism with a Y-bearing cell line. We report the phenotypic data and results of molecular analyses performed in six sporadic Mexican males with 46,XX karyotype. Molecular studies revealed Yp sequences in two individuals (ZFY+ SRY+) with different phenotypes, a third one presented with a smaller segment of Yp (ZFY- SRY+) and complete virilization, while the remaining three were Y-negative and showed hypospadias. In all subjects a hidden mosaicism with a Y-bearing cell line was ruled out due to the absence of Y-centromeric sequences. Our data demonstrate that the phenotype does not always correlate with the presence or absence of Y-sequences in the genome, and confirm that 46,XX maleness is a genetically heterogeneous condition.

Male pseudohermaphroditism due to primary 5 alpha-reductase deficiency: variation in gender identity reversal in seven Mexican patients from five different pedigrees

In the present study, we describe the clinical, endocrinological, psychosexual and biochemical features of 7 Mexican male pseudohermaphrodites with primary 5 alpha-reductase deficiency in whom heterogeneity in the pattern of gender identity change at puberty was observed. The patients belonged to 5 different pedigrees from diverse locations in Mexico. Six of them were admitted to the Hospital during or after puberty. The one prepubertal subject was the sibling of a previously studied patient. Basal serum gonadotropins were determined by double antibody radioimmunoassay. Basal and choriogonadotropin (CG)-stimulated concentrations of androstenedione (A), testosterone (T) and dihydrotestosterone (DHT) were determined by radioimmunoassay after extraction and separation by celite chromatography. Urinary aetiocholanolone, androsterone and C19 and C21 5 beta/5 alpha metabolite ratios were analyzed by capillary gas chromatography. Enzyme activity and androgen receptors were studied in fibroblasts cultured from genital skin. Psychological assessment was performed using the Bender-Gestalt Wechsler Adult Intelligence Scale, the Rorschach Ink Blot and the Thematic Apperception Tests. All 7 patients were unambiguously reared as females; three spontaneously changed their gender identity and role from female to male after puberty, another one changed during psychotherapy at the end of puberty. Two patients (one prepubertal and the other pubertal) have been under therapy during 1.5 years, but due to familial and social factors a female gender has prevailed. The remaining patient consulted at age 15 because of virilization; her female gender identity did not change after more than one year of treatment and due to the fact she was depressed and had suicidal tendencies, the penis and testes were removed.(ABSTRACT TRUNCATED AT 250 WORDS)

SRY alone can induce normal male sexual differentiation

Most individuals with the rare 46,XX male "syndrome" arise due to an unequal interchange between Xp and Yp termini during paternal meiosis. The pattern of Y-sequences in these patients varies considerably, but very few cases have been reported showing only SRY. The phenotype in these patients is also variable ranging from severe impairment of the external genitalia through hypospadias and/or cryptorchidism to occasional normal male phenotype. We report a Mexican 46,XX male patient without genital ambiguities in whom DNA analysis showed the presence of SRY and the absence of ZFY. We conclude that in this case SRY alone was enough for complete male sexual differentiation.

Amplitude regulation of episodic release, in vitro biological to immunological ratio, and median charge of human chorionic gonadotropin in pregnancy

In the present study, we examined the regulation of 24-h serum immunoreactive levels, in vitro biological to immunological (B/I) ratio, and median charge of circulating CG at the end of the first, second, and third trimesters of human gestation. Seven pregnant women were prospectively studied at 12-15, 23-26, and 35-38 weeks of gestation. Blood was sampled every 20 min over a 24-h period, and serum CG concentrations were determined by RIA. Pulse detection and analysis of the 24-h rhythm of serum immunoreactive CG concentrations were carried out by the program Cluster and cosine curve fitting, respectively. The in vitro biological activity of circulating CG was determined by the mouse Leydig cell-testosterone production bioassay, and the median charge of its isoforms was determined by zone electrophoresis in agarose suspension. The immunoreactive levels of CG present at the end of each trimester of gestation fluctuated over a 24-h period; such variability exceeded that of the within-assay coefficient of variation of the CG RIA and could be resolved into a series of CG peaks and valleys. Although no trend in the number of peaks or valleys was systematically found in relation to gestational age, comparisons between the amplitude and area of the CG peaks revealed that these pulse parameters were significantly higher at 12-15 weeks than at 23-26 and 35-38 weeks of gestation. Cosine fits for 24-h rhythms revealed the existence of significant nyctohemeral profiles of serum CG levels in all women studied at 12-15 weeks, in four subjects at 23-26 weeks, and in six women at 35-38 weeks gestation. The time of acrophase was highly homogeneous only between 12-15 weeks of gestation, occurring between 1057-1452 h in six of the women. The in vitro B/I ratio of CG contained in serum pools from 12-15 weeks was significantly (P < 0.05) higher than that exhibited by CG during later gestational periods (B/I ratio at the end of first trimester, 1.14 +/- 0.14; second trimester, 0.87 +/- 0.22; third trimester, 0.79 +/- 0.12). hCG isoforms at 12-15 weeks were more negatively charged than those circulating at 23-26 and 35-38 weeks of gestation. There were no significant differences between the B/I ratio and the median charge of CG molecules from the second and third trimesters. We conclude that serial serum concentrations of CG throughout pregnancy show significant amplitude-modulated pulsatile release and nyctohemeral variations.(ABSTRACT TRUNCATED AT 400 WORDS)

Mixed gonadal dysgenesis: clinical, cytogenetic, endocrinological, and histopathological findings in 16 patients

We describe clinical, cytogenetic, endocrine, and histopathological findings in 16 patients with mixed gonadal dysgenesis (MGD). All patients except 1 presented genital ambiguity and 10 of them had Ullrich-Turner manifestations. The 45,X/46,XY karyotype was the most frequent with a predominance of 45,X cells in both peripheral lymphocytes and gonads. In all cases Müllerian and Wolffian remnants and/or derivatives were found and in some patients both Wolffian- and Müllerian-derived structures were identified on the streak or testicular side. Postpubertal patients exhibited variable degrees of virilization and all of them had hypergonadotropism coexisting with low to normal baseline serum levels of testosterone; their testicular response to human chorionic gonadotropin (HCG) in terms of testosterone secretion was also variable, ranging from minimal to almost a normal response. All prepubertal patients but 1 had normal baseline levels of pituitary gonadotropins and testosterone and their gonadal response to the HCG challenge was highly variable. With the exception of 1 case, who had a 45,X/46,XY(p-) karyotype, no correlation between the cytogenetic data and degree of external genital ambiguity and the hormonal findings was observed. Additional information on the specific structural abnormalities involving the testis-determining gene of the Y chromosome in patients with MGD is needed in order to further understand the mechanisms responsible for the wide variability characteristic of this disorder.

[Clinical, cytogenetic, endocrinological and histological studies in true hermaphrodites]

The clinical, cytogenetic, endocrinological and histologic features of nine mexican patients with true hermaphroditism are reported. Ages at admission ranged from 10 months to 27 years; in seven cases a male sex of rearing was documented, being 46,XX (n = 6) the most frequent karyotype. Basal levels of gonadotrophins, gonadal steroids, and the testosterone response to exogenous HCG varied depending upon age as well as with type and functional status of the gonadal tissue. However, ovarian tissue always preserved its function better than the testicular tissue did. In one of the patients who presented cyclic hematuria, spontaneous ovulation was documented by serum progesterone monitoring (progesterone = 4.3-11.0 ng/mL during luteal phase). Ovo-testis was the most common gonad present; in four cases bilateral ovo-testes were found. Internal genitalia varied depending on the existing gonad, although in all cases a uterus was found. These findings are in accordance with previous reports of individuals bearing true hermaphroditism in other populations.

[Anorexia nervosa: endocrine function during the phases of body weight loss and recovery]

In the present study, we investigated the endocrine status of patients with anorexia nervosa during weight loss (WL), as well as, after weight recovery (WR). A comparison between our findings and those obtained from other populations previously described was made. We studied 12 female patients during WL; 7 of them were reevaluated after WR. Stimulation tests with LRH, TRH, ACTH and insulin-induced hypoglycemia were performed in all cases. During the WL phase, basal serum levels of LH and estradiol, as well as the LH response to LRH, were diminished in comparison with normal values. Basal serum levels of FSH were low or normal. The function of the hypothalamic pituitary-ovarian axis was recovered in all patients restudied; six out of seven returned to ovulation within the first 4 months after WR. The remaining patient presented hypothalamic amenorrhea because of excessive physical activity. Four patients exhibited basal low T3 and T4 levels with normal TSH and a retarded response to TRH during WL. At WR some patients completely recovered their thyroid function while others developed clinical hypothyroidism. Six months after WR all patients were euthyroid. Prolactin response to TRH was unaffected in 10 patients. One patient had basal hyperprolactinemia and hyperesponsiveness to TRH, and the remaining one had only a PRL hyperesponsiveness; this latter finding persisted in one of these patients during the WR phase. This abnormality was attributed to changes in the dopaminergic tone secondary to stress. Although serum growth hormone concentrations were normal in all patients during WL, two of them had basal hypersecretion and hyperesponsiveness to hypoglycemia during WR, which was attributed to protein deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on gonadal dysgenesis: variable expressivity of the XY testicular dysgenesis syndrome; two case reports

Two adult unrelated XY phenotypically female individuals with sexual infantilism and genital ambiguity were studied. Mosaicism was ruled out by the assessment of a normal 46,XY karyotype in four different cell lines. Persistently elevated LH and FSH serum levels with concomitant normal pituitary Gn-RH responsiveness were found. Baseline serum testosterone concentrations were low, but they exhibited a slight though significant rise following HCG stimulation. Surgical and histological findings included the presence of Mullerian and Wolffian derivatives and small bilateral dysgenetic testes with absence of germ cell epithelium, scarce Sertoli cells, and hyperplastic Leydig cells. The overall data indicated an anatomo-functional testicular impairment particularly confined to the tubular compartment. By comparing the clinical and endocrine features of this incomplete form of the XY testicular dysgenesis with the complete and other unusual forms, further evidence is provided of a wide heterogeneity of the syndrome, and a more detailed classification is proposed.

The syndromes of androgen resistance revisited

A revisit to the existing complexities of the androgen resistance syndromes within the frame of our current knowledge was undertaken. Recent contributions of these and other laboratories are presented according to the topographic intracellular location of the underlying abnormalities causing these inherited disorders. Thus, the clinical spectrum, inherited pattern and biochemical features of defective androgen action at the pre-receptor, receptor, and post-receptor levels are examined. In addition, the effects of androgens on the development of gender role is discussed, with particular focus on patients with pre-receptor defects. It was concluded that a better understanding of the nature of the altered events in these syndromes has been achieved over recent years, although several important issues still remain unsolved.

The presence of Müllerian remnants in the complete androgen insensitivity syndrome: a steroid hormone-mediated defect?

A new patient with CAIS who presented Müllerian remnants has been described. Based on recently reported data in experimental animals and considering that human embryos carrying the X-linked CAIS mutation do not express any androgenic effect, we propose that the unopposed estrogenic action in the CAIS-developing embryo might interfere with the mechanism of action of the AMH inhibiting the regression of the female ducts.