Paternal transmission of maleness in XX human beings

XX Disorder of Sex Development is associated with an insertion on chromosome 9 and downregulation of RSPO1 in dogs (Canis lupus familiaris)

Remarkable progress has been achieved in understanding the mechanisms controlling sex determination, yet the cause for many Disorders of Sex Development (DSD) remains unknown. Of particular interest is a rare XX DSD subtype in which individuals are negative for SRY, the testis determining factor on the Y chromosome, yet develop testes or ovotestes, and both of these phenotypes occur in the same family. This is a naturally occurring disorder in humans (Homo sapiens) and dogs (C. familiaris). Phenotypes in the canine XX DSD model are strikingly similar to those of the human XX DSD subtype. The purposes of this study were to identify 1) a variant associated with XX DSD in the canine model and 2) gene expression alterations in canine embryonic gonads that could be informative to causation. Using a genome wide association study (GWAS) and whole genome sequencing (WGS), we identified a variant on C. familiaris autosome 9 (CFA9) that is associated with XX DSD in the canine model and in affected purebred dogs. This is the first marker identified for inherited canine XX DSD. It lies upstream of SOX9 within the canine ortholog for the human disorder, which resides on 17q24. Inheritance of this variant indicates that XX DSD is a complex trait in which breed genetic background affects penetrance. Furthermore, the homozygous variant genotype is associated with embryonic lethality in at least one breed. Our analysis of gene expression studies (RNA-seq and PRO-seq) in embryonic gonads at risk of XX DSD from the canine model identified significant RSPO1 downregulation in comparison to XX controls, without significant upregulation of SOX9 or other known testis pathway genes. Based on these data, a novel mechanism is proposed in which molecular lesions acting upstream of RSPO1 induce epigenomic gonadal mosaicism.

A 46,XX -negative man with complete virilization and infertility as the main anomaly

OBJECTIVE

To report a case of a 46,XX SRY-negative man with a male phenotype and azoospermia.

DESIGN

Case report.

SETTING

Molecular and Cytogenetic Unit in a University Hospital.

PATIENT(S)

A 35-year-old man with complete masculinization who referred to our institution because of a history of several years of infertility.

INTERVENTION(S)

Lymphocytic karyotype and genetic counseling.

MAIN OUTCOME MEASURE(S)

Peripheral blood metaphases were analyzed by standard G-banding and Q-banding. Fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR) analyses were performed.

RESULT(S)

Semen analysis showed azoospermia. Chromosome analysis revealed a 46,XX karyotype; molecular and cytogenetic analyses excluded the presence of SRY (the sex-determining region of the Y chromosome) gene.

CONCLUSION(S)

This case is one of the rare patients reported in the literature in whom testicular differentiation and a complete virilization in a 46,XX chromosomal constitution does not account for a translocation of the SRY gene to the X chromosome or to the autosomes. This finding suggests that other genes downstream from SRY, not yet identified, play an important role in sex determination.

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.

Autosomal XX sex reversal caused by duplication of SOX9

SOX9 is one of the genes that play critical roles in male sexual differentiation. Mutations of SOX9 leading to haploinsufficiency can cause campomelic dysplasia and XY sex reversal. We report here evidence supporting that SOX9 duplication can cause XX sex reversal. A newborn infant was referred for genetic evaluation because of abnormal male external genitalia. The infant had severe penile/scrotal hypospadias. Gonads were palpable. Cytogenetic analysis demonstrated a de novo mosaic 46,XX,dup(17)(q23.1q24.3)/46, XX karyotype. Fluorescent in situ hybridization (FISH) with a BAC clone containing the SOX9 gene demonstrated that the SOX9 gene is duplicated on the rearranged chromosome 17. The presence of SRY was ruled out by FISH with a probe containing the SRY gene and polymerase chain reaction with SRY-specific primers. Microsatellite analysis with 13 markers on 17q23-24 determined that the duplication is maternal in origin and defined the boundary of the duplication to be approximately 12 centimorgans (cM) proximal and 4 cM distal to the SOX9 gene. Thus, SOX9 duplication is the most likely cause for the sex reversal in this case because it plays an important role in male sex determination and differentiation. This study suggests that extra dose of SOX9 is sufficient to initiate testis differentiation in the absence of SRY. Other SRY-negative XX sex-reversed individuals deserve thorough investigation of SOX9 gene.

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 existence of total or partial sex reversal in 46,XX males with genetic mutations not linked to the Y chromosome suggests that several autosomal genes acting in association with SRY may contribute to normal development of the male phenotype. We report a family in which four related 46,XX subjects with no evidence of Y chromosome DNA sequences underwent variable degrees of male sexual differentiation. One 46,XX male had apparently normal male external genitalia whereas his brother and two cousins had various degrees of sexual ambiguity and were found to be 46,XX true hermaphrodites. The presence of male sexual development in genetic females with transmission through normal male and female parents indicates that the critical genetic defect is most likely to be an autosomal dominant mutation, the different phenotypic effects arising from variable penetrance. Other autosomal loci have been implicated in male sexual development but the genetic mechanisms involved are unknown. In this family there may be an "activating" mutation which mimics the initiating role of the SRY gene in 46,XX subjects.

SRY-negative true hermaphrodites and an XX male in two generations of the same family

Two 46,XX true hermaphrodites and one XX male without genital ambiguities are reported. They coexist in two generations of the same pedigree, with paternal transmission and in the absence of SRY (sex-determining region, Y chromosome). These familial cases provide evidence to support the hypothesis that these disorders are alternative manifestations of the same genetic defect, probably an autosomal dominant mutation (with incomplete penetrance) or an X-linked mutation (limited by the presence of the Y chromosome).

Hormonal and molecular genetic findings in 46,XX subjects with sexual ambiguity and testicular differentiation

Ten patients were studied who had sexual ambiguity having in common a 46.XX karyotype and testicular tissue. They were aged from one month to 23 years; some of them were followed through puberty. Eight cases were sporadic and two familial. They were divided into two groups according to finding of surgery and histology: 46, XX males with sexual ambiguity and 46 XX true hermaphrodites (TH). They were no differences in phenotypes (except uterus and ovotestis in TH). The endocrinological data were identical in the two groups: testosterone levels were in the normal range during puberty, then decreased in adulthood. Gonadotrophins were above the normal range at mid-puberty. Gonadal biopsies, regardless of the ovarian part of the ovotestis, were identical in two groups, i.e., normal in the youngest patients, then spermatogonia disappeared afterwards and dysgenesis became obvious. In one case, the ovarian zone of the ovotestis was only detected on serial cuts after gonadectomy. Southern blots displayed the presence of Y specific material in tow cases (PABY-SRY-PO.9). Otherwise, in all other patients, there was the lack of any Y sequences without any differences between the two groups. These data suggests that 46, XX males with sexual ambiguity and 46 XX true hermaphrodites may be alternative expressions of two genetic defects: one, a minimal interchange between Yp and Xp, another, a mutation of an autosomal testis determining factor for the patients without Y detectable material.

A possible common origin of "Y-negative" human XX males and XX true hermaphrodites

We have studied nine patients aged 1 month to 16 years with 46, XX karyotypes and testicular tissue. Some of these patients were followed through puberty. Phenotypically, two presented normal and seven abnormal external genitalia (AG). Among this latter group, four showed hypospadias and three true hermaphroditism (TH). The endocrine data were similar in all three groups: testosterone levels were within normal limits during puberty, decreasing in adulthood; gonadotrophin levels were above the control values at mid puberty. Histologies of the two sub groups of AG patients were identical up to 5 years of age and presented differences when compared with controls, regardless of the ovarian part of the ovotestis. However, in patients older than 8 years, germ cells disappeared and dysgenesis became obvious. In one patient, the ovarian zone of the gonad was detected only after complete serial sections of the removed gonad were examined. Southern blot analysis with Y-DNA probes displayed Y-specific material for the classic 46 XX males and a lack of such sequences for all patients with AG and TH. Based on these findings, we postulate that 46, XX males with AG and 46, XX TH may represent alternative manifestations of the same genetic defect. These data together with those concerning familial cases of 46, XX males with AG and 46, XX TH suggest an autosomally (or pseudoautosomally) determined mechanism.

XX sex reversal in the American cocker spaniel dog: phenotypic expression and inheritance

This study was conducted to define the range of phenotypic expression and mode of inheritance of XX sex reversal in the cocker spaniel dog. Breeding experiments produced F1, F1BC, and F2 generations in which 29 XX true hermaphrodites and 3 XX males were defined by chromosome constitution, serial histologic sections of the gonads, and examination of the internal and external genitalia. In XX true hermaphrodites, the most common combination of gonads was bilateral ovotestes, followed by ovotestis and ovary, then ovotestis and testis. The amount of testicular tissue in the two gonads was closely correlated within each true hermaphrodite. The distribution of testicular tissue within ovotestes of true hermaphrodites was consistent with the hypothesis that testicular differentiation is initiated in the center of the gonad and spreads outward. XX males had bilateral aspermatogenic testes and the internal ducts and external genitalia were more masculinized than in true hermaphrodites. Results of breeding experiments are consistent with autosomal recessive inheritance, the affected phenotype being expressed only in dogs with an XX chromosome constitution. The phenotypic expression and mode of inheritance of this disorder is compared to XX sex reversal in humans and other animals.

Familial 46,XX males coexisting with familial 46,XX true hermaphrodites in same pedigree

Reported here is a family with which 46,XX males and 46,XX true hermaphrodites coexist. The propositus was a paternal uncle with 46,XX true hermaphroditism. One of his brothers fathered a 46,XX daughter with true hermaphroditism; a second brother fathered two 46,XX males. Both fathers have normal male karyotypes and phenotypes. No evidence for chromosomal mosaicism or any additional chromosomal abnormalities was obtained. We conclude that inheritance of the abnormality is most likely via paternal transmission of an autosomal testis-determining factor. This family provides evidence to support the hypothesis that 46,XX true hermaphrodites and 46,XX males represent alternative manifestations of the same genetic defect.

The presence of intersexuality in patients with advanced hypospadias and undescended gonads

We studied 20 patients with advanced degrees of hypospadias and undescended testes for the presence of an intersex disorder. A comprehensive clinical, cytogenetic, endocrinological and surgical evaluation was performed. All patients were found to have an intersex disorder, including 10 with male pseudohermaphroditism and 10 with a gonadal/genetic intersex disorder. In the latter group 4 patients had mixed gonadal dysgenesis, 3 had dysgenetic male pseudohermaphroditism, 1 had the 46XX male syndrome, 1 had true hermaphroditism and 1 had Klinefelter's syndrome. Genetic and gonadal intersex disorders were more frequent in patients with a unilateral undescended testis and perineal hypospadias.

Chromosome Y-specific DNA in related human XX males

Human 'XX males' are sterile males whose chromosomes seem to be those of a normal female. About 1 in 20,000 males has a 46, XX karyotype, and most cases are sporadic, that is, they are without familial clustering. It has long been argued that maleness in XX males may result from the undetected presence of a small, testis-determining fragment of the Y chromosome, and there is strong evidence for this in sporadically occurring XX males. Indeed, the genomes of three of four sporadic XX males tested were found to contain certain Y-specific DNA sequences. A pedigree in which three XX males occur has been interpreted as being consistent with autosomal recessive inheritance of maleness, and it has been argued that the basis of XX maleness in this family is fundamentally different from that in the sporadic cases. However, we report here that these related XX males, like the sporadic cases, contain portions of the Y chromosome. The portion of the Y chromosome present in one of the three XX males differs from that present in the other two.

Preservation of gonadal function in true hermaphroditism

Twelve documented cases of true hermaphroditism have been studied since 1965; there was histological evidence of both ovarian and testicular tissue in all cases. The clinical, anatomical, and therapeutic procedures are reviewed with special emphasis on gonadal morphology, histology, and function. Seven patients were reared as females, 5 as males; 6 are now postpubertal and 3 are more than 30 years old. Five underwent bilateral castration; in seven cases, only the discordant gonadal tissue has been removed so that these patients may have endogenous gonadal secretion in keeping with their sex of rearing.

Genetic homology and crossing over in the X and Y chromosomes of Mammals

The "X-Y crossover model" described in this paper postulates the (1) the pairing observed between the X and the Y chromosome at zygotene is a consequence of genetic homology, (2) there is a single obligatory crossover between the X and Y pacing segments, and (3) the segment of the X which pairs with the Y is protected from subsequent inactivation. Genes distal to the proposed crossover ("pseudoautosomal genes") will appear to be autosomally inherited because they will be transmitted to both male and female offspring. Some criteria for identifying pseudoautosomal genes are outlined. The existence of a single obligatory crossover between the X and Y of the mouse is strongly supported by a recent demonstration that the sex-reversing mutation Sxr, which is passed equally to XX and XY offspring by male carriers, is transmitted on the sex chromosomes. Pseudoautosomally inherited genes may also be responsible for XX sex reversal in goats and familial XX sex reversal in man.

The diagnosis and management of intersex

The patient whose genitalia are ambiguous or are inappropriate for the assigned sex presents the physician with a set of problems requiring a thorough grasp of sexual differentiation, development and function. Although several reviews have covered various aspects of these matters, these texts do not cover recent advances in understanding normal and abnormal sexual development nor do they provide an integrated guide to the management of intersex cases. Our objectives are to show the clinical relevance of recent advances in understanding the determinants of normal and abnormal sexual differentiation, to indicate the improved diagnostic procedures now available and to provide specific guidelines for optimal case management in the light of current medical knowledge and psychological and ethical understanding.

Heteromorphic X chromosomes in 46,XX males: evidence for the involvement of X-Y interchange

G- and R-banded chromosome preparations from eight of twelve 46,XX males, with no evidence of mosaicism or a free Y chromosome, were distinguished in blind trials from preparations from normal 46,XX females by virtue of heteromorphism of the short arm of one X chromosome. Photographic measurements on X chromosomes and on chromosome pair 7 in cells from twelve 46,XX males, eight 46,XX females, and four 46,XY males revealed a significant increase in the size of the p arm of one X chromosome in the group of XX males, independently characterised as being heteromorphic for Xp. No such differences were observed between X chromosomes of normal males and females or between homologues of chromosome pair 7 in all groups. The heteromorphism in XX males is a consequence of an alteration in shape (banding profile) and length of the tip of the short arm of one X chromosome, and the difference in size of the two Xp arms in these 46,XXp+ males ranged from 0.4% to 22.9%. From various considerations, including the demonstration of a Y-specific DNA fragment in DNA digests from nuclei of one of three XX males tested, it is concluded that the Xp+ chromosome is a product of Xp-Yp exchange. These exchanges are assumed to originate at meiosis in the male parent and may involve an exchange of different amounts of material. The consequences of such unequal exchange are considered in terms of the inheritance of genes located on Yp and distal Xp. No obvious phenotypic difference was associated with the presence or absence of Xp+. Thus, some males diagnosed as 46,XX are mosaic for a cryptic Y-containing cell line, and there is now excellent evidence that maleness in others may be a consequence of an autosomal recessive gene. The present data imply that in around 70% of 46,XX males, maleness is a consequence of the inheritance of a paternal X-Y interchange product.

Two XX male brothers

Two brothers with XX male syndrome with penoscrotal hypospadias are reported. Chromosomal analysis of cells from the peripheral blood, skin, and testes revealed a normal female karyotype in both subjects. Biopsy of both testes in the brothers showed histological features of normal immature testes and no evidence of ovarian structures. Neither vagina, uterus nor fallopian tubes could be detected either by exploratory laparotomy or retrograde urethrography. Results of endocrine studies on serum gonadotropins (LH and FSH) and testosterone levels as well as their responses to LH-RH and hCG stimulation tests were normal for age. Studies of various genetic markers, including the Xg blood type and erythrocyte enzymes, were performed in the probands and their parents. Possible explanations for the paradoxical occurrence of testes in XX males and for the familial occurrence are discussed.

Familial XX true hermaphroditism and the H-Y antigen

Two 46,XX sibs, one of female, one of male gender, and both with ambiguous external genitalia and ovotestis, were H-Y positive. The mother was H-Y negative. It is assumed that the underlying mutation was transmitted by the father, resulting in an autosomal dominant mode of inheritance. The common origin and the nature of the mutation leading to XX sex reversal are discussed.

In vitro studies of gonadal organogenesis in the presence and absence of H-Y antigen

In a very strict sense, the primary (gonadal) sex of mammals is determined not so much by the presence or absence of the Y but the expression or nonexpression of the evolutionary extremely conserved plasma membrane H-Y antigen. The central somatic blastema of embryonic indifferent gonads contains one cell lineage characterized by the possession of S-F differentiation antigen that differentiates into testicular Sertoli cells in the presence of H-Y and into ovarian follicular (granulosa) cells in its absence. This cell lineage appears to play the most critical role in gonadal differentiation. Whether or not testicular Leydig cells and ovarian theca cells are similarly derived from the common cell lineage has not been determined. Nevertheless, if given H-Y antigen, presumptive theca-cell precursors of the fetal ovary acquire hCG (LH?)-receptors-the characteristic of fetal Leydig cells.

Mosaicism in XX males

Three males with a 46,XX karyotype are described. In two of them, evidence of a Y-containing line was found. In the first case, 1 of 500 lymphocyte metaphases was 48,XXY. In the second, 1 of 400 oral mucosa cells contained a Y body. The proportion of low-grade XX/XXY mosaics found among XX males now stands at about 17%.

Genetic basis of XX male syndrome and XX true hermaphroditism: evidence in the dog

Serological analysis of white blood cells from the members of a family of American cocker spaniels indicates that a form of abnormal sexual development, in which individuals with a female karyotype have testes or ovotestes, is caused by anomalous transmission of male-determining H-Y genes.

True hermaphroditism: a clinical description and a proposed function for the long arm of the Y chromosome

True hermaphroditism is a very rare form of ambiguous genitalia characterized by the presence of both ovarian and testicular tissue in the same individual. Sixty percent of these patients have a 46,XX karyotype; however, most have H-Y antigen detectable. Since H-Y antigen is thought to be the gene product of the short arm of the Y, then the short arm must be present somewhere in the karyotype. Products of the short arm loci are thought to initiate testicular differentiation and male determination. The long arm of the Y has not been detected in true hermaphrodites. Testicular histology in true hermaphrodites is characterized by spermatogenic arrest, causing us to speculate that the long arm of the Y might be essential for germ cell maturation beyond the spermatogonia state.

The phenotypic expression of selective disorders of male sexual differentiation

Normal male sexual differentiation is the result of a series of individual steps that occur in an orderly fashion: testicular differentiation, müllerian regression, wolffian duct development, differentiation of the urogenital sinus and external genitalia, phallic growth and descent of the testes. Herein we present the pathophysiological mechanism by which selective disorders disrupt these normal events and produce specific phenotypes.

A new case of XX-male (XX/XXY mosaic)

We report a 10-year-old male patients with the predominant karyotype 46,XX. In only one cell of the testis culture a metaphase with 47,XX+G was found. The theories of etiology of XX-males and the reported cases of XX/XXY-mosaics in the literature were discussed.

Two XX males in one family and additional observations bearing on the etiology of XX males

Two XX males who were second cousins are reported. A genetic mechanism producing maleness is suggested. The putative factor had been transmitted solely through males, which excludes the possibility of a heritable X-Y interchange. Recent reports on fluorescent Y chromatin in Sertoli cells of XX males prompted investigations into the fluorescence patterns of testicular cells. Sertoli cells from three XX males displayed brightly fluorescent spots, but it was concluded that they did not represent Y chromosomes. Evidence for this conclusion was obtained from the study of testicular fluorescence in XX, XXY and XY males. No visually detectalbe cytogenetic evidence for an increase in length or altered banding pattern of one of the X chromosomes was found in three XX males. We conclude that an autosomal gene is the most likely explanation of the male differentiation in the two XX males presented here.

Serologic detection of a y-linked gene in xx males and xx true hermaphrodites

To test the hypothesis that H-Y antigen (present on both somatic and germ cells in normal males but not normal females) is essential for testicular differentiation, we studied four XX males and three XX true hermaphrodites. Blood cells from six subjects and cultured gonadal fibroblasts from a seventh expressed H-Y antigen. Since expression of this antigen requires the presence of a gene normally carried by the Y chromosome, this gene, and perhaps additional Y chromosomal material, should have been present in the genome of these subjects. In one patient this presence is accounted for by a Y-to-X translocation, detectable by chromosome banding. In another a normal Y chromosome was present in a minor population of cells. In the remaining five, no karyotypic abnormality was detectable. Immunologic detection of H-Y antigen is a sensitive test for the presence of the Y chromosome or of its male-determining segment.

On the evolution of X-chromosome inactivation in mammals and the clinical consequences to man--a hypothesis

A clinical analysis of abnormal sex chromosome states in man suggests that Lyon's recent X-Y translocation hypothesis for the evolution of X-chromosome inactivation in mammals most likely would have lead to an evolutionary dead-end. Therefore, as an alternate I have hypothesized that: X-chromosome inactivation in somatic cells of mammals could have evolved by a complementary process of one by one heterozygous physical deletion in males and heterozygous inactivation in females of genes for "somatic" traits scattered throughout the genome whose effective output had become 50% excessive during prior evolution. However, this complementary process could occur safely only if the genes so deleted or inactivated first segregated by chance onto the evolving sex-chromosomes via a one by one reciprocal exchange for non-sex related genes already there. The complementary process thereby would allow slow evolution of the Y-chromosome in the male and X-chromosome inactivation in the female. Evolution of X-chromosome inactivation in this manner is compatible with Ohno's observation of "conservation" of the X-chromosome in mammals; and the occurrance of clinical "somatic" abnormalities in the abnormal X or Y chromosome states of man despite X-chromosome inactivation.

Familial true hermaphrodism in three siblings: clinical, cytogenetic, histological and hormonal studies

Three affected siblings with the hermaphrodism are described. The propositi showed the following characteristics: male phenotype and gender role, hypospadias, bilateral scrotal ovotestes with palpable nodules, and absence of müllerian structures. The X chromatin was positive and the Y chromatin was negative in the 3 affected subjects. Their karyotype in peripheral blood lymphocytes and in gonadal fibroblasts was 46,XX and no Y chromosome fluorescence was observed. Plasma FSH was elevated in the 2 older patients and plasma LH was elevated only in the oldest. Plasma testosterone was low and plasma estradiol high in the 3 siblings; plasma progesterone was elevated in 2, but normal in 1 sibling. Since some of the clinical characteristics of these 3 affected siblings are not the most common features in the majority of sporadic cases of true hermaphrodism, it is suggested that the presence of all of them may be the first clue for the clinical suspicion of the familial type of true hermaphrodism.

Pseudohermaphroditis, with testes and a 46, XX karyotype

A 14 4/12-year-old white girl, evaluated for progressive virilization and clitormegaly, was found to have the unusual combination of a 46, XX karyotype, well-developed Mullerian structures, and dysgenetic testes with Leydig cell hyperplasia. Although there have been previous case reports of 46, XX males, in all of these patients development of the Mullerian ducts had been suppressed. When contemporary classifications of human disorders of sexual differentation were reviewed, no report of a similar patient was found. We speculate that the genotype and phenotype in our patient correspond to the genetic intersexuality of the hornless goat, thereby raising the possibility that the human autosome may play a role in the control of sexual development.

XX males: two new cases

Two new cases of phenotypic males with 46,XX karyotype are presented. Fluorescence, autoradiographic and centromeric heterochromatin studies in several lines, including testicular cells, failed to demonstrate the existence of the Y chromosome or the existence of distal Yq material translocated to another chromosome in the two patients. The Xg study in one of the patients and his family provided direct evidence of transmission of an X chromosome from father to son. We present indirect evidence favoring the mutation theory to explain the XX male phenotype.

An XX male: cytogenetic and endocrine studies

A 3 year old black male with ambiguous genitalia had a 46, XY karyotype in a bone marrow culture and an intermediate buccal smear result, suggestive of a mosaic of chromatin positive and chromatin negative cells. Upon re-evaluation at age 15 years, he has a 30% positive buccal smear and a 46, XX karyotype in cultures of peripheral blood lymphocytes, skin fibroblasts, bone marrow, and testis. No Y-body fluorescence was detectable in interphase cells from the testicular biopsy or the various cultures. The testicular biopsy appeared similar to that of XXY males, and primary hypogonadism was documented by elevated LH (107 mIU/ml) and FSH (57 mIU/ml) levels in conjunction with low testosterone (142 ng/100 ml). Administration of hCG produced qualitatively normal acute responses of testosterone and estrogens. The cytogenetic data provide support for the theory that at least some XX males once had a Y-containing cell line which was subsequently lost.

Some experiments of nature with sex

Professor Penrose was a human geneticist but above all a human biologist interested in all aspects of man's adaptation and behaviours. However, I need not remind you of the fact that his interests were wider. They were, among others, with the field of biology itself. This interest was one reason why he was particularly delighted with some of the discoveries made on human chromosomes and their anomalies, and he shared very abundantly in the work and in the excitement of these discoveries.