XX True Hermaphrodites Research Articles

BRCA1 and BRCA2 protein expressions in an ovotestis of a 46, XX true hermaphrodite.

BRCA1 and BRCA2 breast cancer susceptibility genes encode proteins, the normal cellular functions of which are complex and multiple, and germ-line mutations in individuals predispose both to breast and to ovarian cancer. There is nevertheless substantial evidence linking BRCA1 and BRCA2 to homologous recombination and DNA repair, to transcriptional control and to tissue proliferation. There is controversy regarding the localization of BRCA1 and BRCA2 proteins to either nucleus or cytoplasm and whether the expression is present in premeiotic germ cells or can still be expressed in mitotic spermatogonia. We report herein an immunohistochemical study of BRCA1 and BRCA2 distribution in a rather unusual tissue (an ovotestis), which addresses this issue.

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite

Yp-specific sequences, including the testicular determinant gene SRY, have been detected and located in a 46,XX true hermaphrodite individual, using PCR amplification and fluorescent in situ hybridization (FISH). Among different Y chromosome loci tested, it was only possible to detect Yp sequences. The Y-centromere and Yq sequences were absent. Unexpectedly, the Y fragment was translocated to the long arm of one of the X chromosomes, at the Xq28 level, and the derivative (X) chromosome of the patient lacked q-telomeric sequences. To our knowledge, this is the first Yp/Xq translocation reported. The coexistence of testicular and ovarian tissue in the patient may have arisen by differential inactivation of the Y-bearing X chromosome, in which Xq telomeric sequences are missing. The possible origin of the Yp/Xq translocation, during paternal meiosis or in somatic paternal cells, is discussed.

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite

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.

SRY protein is expressed in ovotestis and streak gonads from human sex-reversal

In mammals, a master gene located on the Y chromosome, the testis-determining gene SRY, controls sex determination. SRY protein is expressed in the genital ridge before testis determination, and in the testis it is expressed in Sertoli and germ cells. Completely sex-reversed patients are classified as either 46,XX males or 46,XY females. SRY mutations have been described in only 15% of patients with 46,XY complete or partial gonadal dysgenesis. However, although incomplete or partial sex-reversal affects 46,XX true hermaphrodites, 46,XY gonadal dysgenesis, and 46,XX/46,XY mosaicism, only 15% of the 46,XX true hermaphrodites analyzed have the SRY gene. Here, we demonstrate that the SRY protein is expressed in the tubules of streak gonads and rete testis, indicating that the SRY protein is normally expressed early during testis determination. Based on these results, we propose that some factors downstream from SRY may be mutated in these 46,XY sex-reversal patients. We have also analyzed SRY protein expression in the ovotestis from 46,XX true hermaphrodites and 46,XX/46,XY mosaicism, demonstrating SRY protein expression in both testicular and ovarian portions in these patients. This suggests that the SRY protein does not inhibit ovary development. These results confirm that other factors are needed for complete testis development, in particular, those downstream of the SRY protein.

Sry‐Negative XX Sex Reversal in a Family of Norwegian Elkhounds

Two related female Norwegian Elkhounds were evaluated at 6 and 8 months of age for enlarged clitori. Both had a 78 XX karyotype. Histology of their internal reproductive tracts demonstrated 1 to be an XX true hermaphrodite with bilateral ovotestes and the other to be an XX male with bilateral aspermatogenic testes. Polymerase chain reaction‐based tests of genomic DNA showed that both dogs lacked Sry, the testis‐determining gene. Pedigree analysis was consistent with an autosomal recessive mode of inheritance, as has been reported in the American Cocker Spaniel and the German Shorthaired Pointer. This is the 1st reported case of familial Sry‐negative XX sex reversal in the Norwegian Elkhound. A summary of 34 previously unreported cases of dogs with masculinized external genitalia and a normal 78 XX karyotype seen from 1980 to 1997 is given.

Incomplete masculinisation of XX subjects carrying the SRY gene on an inactive X chromosome

46,XX subjects carrying the testis determining SRY gene usually have a completely male phenotype. In this study, five very rare cases of SRY carrying subjects (two XX males and three...

CLINICAL AND MOLECULAR ANALYSIS OF XX SEX REVERSED PATIENTS

Purpose The XX male syndrome presents with a spectrum of clinical appearances from phenotypic male individuals to true hermaphrodites. Previous reports established the sex determining region of the Y chromosome (SRY) gene as the testis determining factor. However, a subset of XX sex reversed male individuals exists without a translocation of SRY deoxyribonucleic acid (DNA) material to the X chromosome. In addition to clinical or endocrinological criteria, Y DNA probe studies, and radiological and surgical evaluation as indicated are necessary for an accurate diagnosis. Materials and Methods We evaluated 5 XX sex reversed patients (2 true hermaphrodites and 3 male individuals) by physical examination, pedigree analysis, endocrinological testing, molecular analysis of Y DNA, radiological studies and surgery (exploration and/or biopsy). Results All patients were SRY gene negative. Two patients were siblings. Complete endocrinological testing was negative in all cases. Two patients had a normal male phenotype. Radiological findings confirmed by cystoscopy or laparoscopy revealed a utricle, vesicoureteral reflux, and cervix and uterus in various patients. Gonadal biopsy showed ovotestes or ovary and testis in the 2 true hermaphrodites. The 3 XX male individuals had normal immature testes on biopsy. Conclusions Categories of XX sex reversal include classic XX male individuals with normal phenotypes, nonclassic XX male individuals with sexual ambiguity and XX true hermaphrodites. Simple translocation of the SRY gene to the X chromosome does not always account for testicular differentiation and a male phenotype. The masculinization of our patients in the absence of SRY suggests an alteration of 1 or more downstream Y, X or autosomal testis determining genes. We present another theory for male sex determination, including a downstream gene on the X chromosome in which expression is influenced by X inactivation. Y DNA genomic analysis, radiological studies and laparoscopic evaluation with gonadal biopsy as appropriate are recommended for complete assessment and treatment of these intersex patients.

Clinical and molecular analysis of XX sex reversed patients.

The XX male syndrome presents with a spectrum of clinical appearances from phenotypic male individuals to true hermaphrodites. Previous reports established the sex determining region of the Y chromosome (SRY) gene as the testis determining factor. However, a subset of XX sex reversed male individuals exists without a translocation of SRY deoxyribonucleic acid (DNA) material to the X chromosome. In addition to clinical or endocrinological criteria, Y DNA probe studies, and radiological and surgical evaluation as indicated are necessary for an accurate diagnosis. We evaluated 5 XX sex reversed patients (2 true hermaphrodites and 3 male individuals) by physical examination, pedigree analysis, endocrinological testing, molecular analysis of Y DNA, radiological studies and surgery (exploration and/or biopsy). All patients were SRY gene negative. Two patients were siblings. Complete endocrinological testing was negative in all cases. Two patients had a normal male phenotype. Radiological findings confirmed by cystoscopy or laparoscopy revealed a utricle, vesicoureteral reflux, and cervix and uterus in various patients. Gonadal biopsy showed ovotestes or ovary and testis in the 2 true hermaphrodites. The 3 XX male individuals had normal immature testes on biopsy. Categories of XX sex reversal include classic XX male individuals with normal phenotypes, nonclassic XX male individuals with sexual ambiguity and XX true hermaphrodites. Simple translocation of the SRY gene to the X chromosome does not always account for testicular differentiation and a male phenotype. The masculinization of our patients in the absence of SRY suggests an alteration of 1 or more downstream Y, X or autosomal testis determining genes. We present another theory for male sex determination, including a downstream gene on the X chromosome in which expression is influenced by X inactivation. Y DNA genomic analysis, radiological studies and laparoscopic evaluation with gonadal biopsy as appropriate are recommended for complete assessment and treatment of these intersex patients.

Detection of the Sex-Determining Region of the Y Chromosome in 46,XX True Hermaphroditism

Objectives: Two cases of 46,XX true hermaphroditism were analyzed for two Y-DNA sequences, including the recently cloned gene for male testis determination, the sex-determining region of the Y chromosome (SRY). Methods: Polymerase chain reaction was performed to amplify the SRY. DNA was prepared from peripheral blood lymphocytes as well as from gonadal tissue preserved in a paraffin block. Results: One hermaphrodite contained the SRY sequences in peripheral blood lymphocytes and the testicular part of ovotestis tissue preserved in a paraffin block, while in the second patient these sequences were not detected. Conclusions: The SRY positive subject resulted from occult Y mosaicism rather than from X–Y translocation. Testis differentiation in the SRY negative subject may have been caused by mutation of a gene on the X chromosome or, alternatively, on an autosome.

Abnormalities of gonadal differentiation

Gonadal differentiation involves a complex interplay of developmental pathways. The sex determining region Y (SRY) gene plays a key role in testis determination, but its interaction with other genes is less well understood. Abnormalities of gonadal differentiation result in a range of clinical problems. 46,XY complete gonadal dysgenesis is defined by an absence of testis determination. Subjects have female external genitalia and come to clinical attention because of delayed puberty. Individuals with 46,XY partial gonadal dysgenesis usually present in the newborn period for the valuation of ambiguous genitalia. Gonadal histology always shows an abnormality of seminiferous tubule formation. A diagnosis of 46,XY true hermaphroditism is made if the gonads contain well-formed testicular and ovarian elements. Despite the pivotal role of the SRY gene in testis development, mutations of SRY are unusual in subjects with a 46,XY karyotype and abnormal gonadal development. 46,XX maleness is defined by testis determination in an individual with a 46,XX karyotype. Most affected individuals have a phenotype similar to that of Klinefelter syndrome. In contrast, subjects with 46,XX true hermaphroditism usually present with ambiguous genitalia. The majority of subjects with 46,XX maleness have Y sequences including SRY in genomic DNA. However, only rare subjects with 46,XX true hermaphroditism have translocated sequences encoding SRY. Mosaicism and chimaerism involving the Y chromosome can also be associated with abnormal gonadal development. However, the vast majority of subjects with 45,X/46,XY mosaicism have normal testes and normal male external genitalia.

An autosomal or X linked mutation results in true hermaphrodites and 46,XX males in the same family.

It is now well established that the differentiation of the primitive gonad into the testis during early human embryonic development depends on the presence of the SRY gene. However, the...

Sry gene detection in gonads of intersex patients using FISH.

A candidate gene for sex determination was localized within a 35 kb region of the Y chromosome immediately adjacent to the pseudoautosomal boundary. Here, we describe a study of Sry detection in the gonads of intersex patients including 5 male pseudohermaphrodite (MPH), 4 XX true hermaphrodite (TH) and each 1 mixed gonadal dysgenesis (MGD) and XX sex reversal, and in the clitoris of 3 female pseudohermaphrodite (FPH) by fluorescent in situ hybridization (FISH). Sry gene was observed in all cases of MPH and each case of MGD and sex reversal in contrast to bare expression in all cases of FPH and most of TH. To our knowledge, the Sry gene itself functions testicular determination in almost all intersex cases except true hermaphrodite, a distinguished type of intersex in a different pathogenesis. In addition, FISH might be useful to detect the translocated Sry gene and localize the signal with ease.

XX true hermaphroditism in southern African blacks: exclusion of SRY sequences and uniparental disomy of the X chromosome.

A molecular investigation of 16 Bantu-speaking Black XX true hermaphrodites was undertaken in an attempt to determine the cause of the disorder. Y-specific sequences, including sequences mapping to the sex-determining region of the Y, were shown to be absent from lymphocyte tissue of all 16 patients tested. Y chromosome sequences were also absent from the ovarian and testicular components of both ovotestes of a single XX true hermaphrodite, thus excluding gonadal mosaicism involving Y chromosome sequences. Since there is evidence for Xp genes involved in testis determination/differentiation, uniparental disomy of the X chromosome was investigated in 14 XXTH families. Uniparental disomy was excluded in 12 of the 14 families, and isodisomy was excluded in the remaining two cases.

Clinical and anatomical spectrum in XX sex reversed patients. Relationship to the presence of Y specific DNA-sequences.

Testicular differentiation can occur in the absence of the Y chromosome giving XX sex-reversed males. Although Y chromosomal sequences can be detected in the majority of male subjects with a 46,XX karyotype, several studies have shown that approximately 10% of patients lack Y material including the SRY gene. The aim of this study was to see if the classification of XX sex-reversed individuals into three groups, Y-DNA-positive phenotypically normal XX males, Y-DNA-negative XX males with genital ambiguities and Y-DNA-negative true hermaphrodites can be applied to our cases. Endocrinological and genetic studies were conducted in 20 XX sex-reversed patients. Twenty patients with various phenotypes were studied. They were between 20 days and 35 years old. Ten presented ambiguous external genitalia (Prader's stages II to IV). After laparotomy or gonadal biopsy, the diagnosis was 46,XX true hermaphroditism in five, and XX male in 15. Blood samples were obtained from all patients for hormonal and molecular studies. Basal levels of testosterone, oestradiol and pituitary gonadotrophins were measured by RIA. In addition, two stimulation tests were performed: gonadotrophin stimulation with GnRH and testicular stimulation with hCG. Several Y-specific DNA sequences of the short arm of the Y chromosome were analysed by Southern blot and polymerase chain reaction methods. In this study, three categories of XX sex-reversed individuals were observed: phenotypically normal males with or without gynaecomastia, males with genital ambiguities, and true hermaphrodites. Endocrinological data were similar in XX males and in true hermaphrodites. Testosterone levels exhibited normal (n = 9) or decreased (n = 11) values. The hCG response was low. FSH and LH were elevated in 13 patients. Molecular analysis in ten patients showed varying amounts of Y material including the Y boundary and SRY. Ten patients with various phenotypes lacked Y chromosomal DNA. There was no relation between Leydig cell function (as indicated by testosterone levels before or after hCG stimulation) and the presence of Y chromosome material. Although the presence of Y-specific DNA generally results in a more masculinized phenotype, exceptions do occur. In the Y-DNA-negative group, complete or incomplete masculinization in the absence of SRY suggests a mutation of one or more downstream non-Y, testis-determining genes.

Analysis of the Sex-determining Region of the Y Chromosome (SRY) in a Case of 46, XX True Hermaphrodite

We present here an 18-month-old 46, XX true hermaphrodite with hypospadias and bifid scrotum. The patient's gonadotropin levels before and after the LH-RH test were within the normal range. The serum testosterone level was <5.0 ng/dL and rose to 381 ng/dL after the human chorionic gonadotropin test. The serum estradiol level was <10 pg/mL and did not rise after the human menopausal gonadotropin test. Pelvic magnetic resonance imaging (MRI) revealed a vagina-like structure. Bilateral gonads were palpable in the scrotum, and histologically, they were ovotestes. We could find no sequence of sex-determining region Y (SRY) in the ovotestes, perineal skin, or leukocytes by polymerase chain reaction (PCR) methods. Other Y-specific DNA sequences were also not detected.These findings suggest that some XX true hermaphroditism is caused by a very low proportion of Y-containing cells, which cannot be detected by PCR methods. Alternatively, a mutation of one of the down-stream genes of SRY could be involved in the pathogenesis.

Nonrandom inactivation of the Y-bearing X chromosome in a 46, XX individual: evidence for the etiology of 46, XX true hermaphroditism

We previously reported a subject with 46,XX true hermaphroditism who had a 46,X,del(X) karyotype and Y-chromosomal sequences in genomic DNA. We hypothesized that the Y-chromosomal sequences were translocated to the deleted X chromosome and that the incomplete testis determination of this individual was the result of inactivation of the translocated X chromosome. In situ hybridization studies demonstrated that the Y-chromosomal sequences were located on the distal portion of the short arm of the deleted X chromosome. Investigation of the replication of the X chromosome, using a modified R-banding technique and localization of Y-chromosomal sequences by in situ hybridization, showed that the translocated X chromosome was late replicating in all 100 EBV-transformed lymphoblasts that were examined. By contrast, when cells from a subject with 46,XX maleness were studied, the translocated X chromosome was late replicating in only 21 of 47 cells. As the late-replicating X chromosome is presumed to be the inactive X chromosome, selection of cells in which the Y-bearing X chromosome has been inactivated may play a role in the incomplete testis determination in subjects with "Y-positive" 46,XX true hermaphroditism.

Familial true hermaphroditism: paternal and maternal transmission of true hermaphroditism (46,XX) and XX maleness in the absence of Y-chromosomal sequences

We report on 46,XX true hermaphroditism and 46,XX maleness coexisting in the same pedigree, with maternal as well as paternal transmission of the disorder. Molecular genetic analysis showed that both hermaphrodites as well as the 46,XX male were negative for Y-chromosomal sequences. Thus, this pedigree is highly informative and allows the following conclusions: first, the maternal as well as paternal transmission of the disorder allows the possibility of an autosomal dominant as well as an X-chromosomal dominant mode of inheritance; second, testicular determination in the absence of Y-specific sequences in familial 46,XX true hermaphrodites as well as in 46,XX males seems to be due to the varying expression of the same genetic defect; and third, there is incomplete penetrance of the defect.

Cell migration and chimerism after whole-organ transplantation: The basis of graft acceptance

Improvements in the prevention or control of rejection of the kidney and liver have been largely interchangeable (1, 2) and then applicable, with very little modification, to thoracic and other organs. However, the mechanism by which anti rejection treatment permits any of these grafts to be “accepted” has been an immunological enigma (3, 4). We have proposed recently that the exchange of migratory leukocytes between the transplant and the recipient with consequent long-term cellular chimerism in both is the basis for acceptance of all whole-organ allografts and xenografts (5). Although such chimerism was demonstrated only a few months ago, the observations have increased our insight into transplantation immunology and have encouraged the development of alternative therapeutic strategies (6).

Cell migration and chimerism after whole-organ transplantation: The basis of graft acceptance

Cell migration and chimerism after whole-organ transplantation: The basis of graft acceptance