Department of Endocrinology & Diabetes, The Royal Children’s Hospital, Melbourne; University of Melbourne Department of Paediatric; and Murdoch Childrens Research Institute, Melbourne Australia. Telephone: +61 3 9345 5954, Fax: +61 3 9345 4615, Email: email@example.com
Disorders of sex development
A 2004 consensus guidelines workshop held in Chicago1 resolved that the use of the term ‘intersex’ should be abandoned and replaced with a new term, ‘disorders of sex development’ or DSD. The workshop defined DSDs as congenital conditions in which gonadal, anatomical or chromosomal sex is atypical. Terminology was revised, removing a number or terms that were considered pejorative (e.g male and female pseudohermaphroditism, testicular feminization, adrenogenital syndrome, true hermaphroditism, XX male syndrome, sex reversal) and introducing a new classification (Table 1) based on karyotype, the type of gonad, and the underlying functional defect, when known. Some genital anomalies of unknown etiology, such as bladder extrophy and cloacal extrophy, which do not readily fit into such a classification are grouped as “other”. The benefits of the new diagnostic terms are that they are neutral, descriptive and objective, making them more useful to clinicians when explaining a DSD to the parents of a child or at a later stage, to the patient.
Some conditions, such as Turner syndrome and Klinefelter syndrome, which were not previously thought of as intersex conditions, are now redefined as DSD because of the sex chromosome abnormality.
Some patients with DSD have atypical anatomy. This may take the form of
Failure to refer appropriately may expose the patient to
In some forms of DSD, the gonads are atypical. They may be
Sex chromosome aneuploidy is surprisingly common, affecting 1:600 in the community. The most common variations are
Sex determination and sexual differentiation
Sex determination is the process in which the indeterminate gonad becomes either a testis or an ovary. Sexual differentiation is the phenotypic change that occurs in the reproductive organs to make them male or female after the gonad starts to function as a testis or an ovary. In mammalian systems5, sex determination along the male pathway is initiated by the presence of the SRY gene on the Y chromosome. This triggers a cascade of genetic interactions, which is shown in Figure 1.
The first morphological change indicating that the gonad is going to be a testis is the appearance of sex cords which are comprised of Sertoli cells. The foetal Sertoli cells secrete anti-Mullerian hormone (AMH, also called Mullerian Inhibitory Substance, or MIS) and Inhibin B. Germ cells migrate into the developing testis from the allantois. Leydig cells also migrate into the testis, from the mesonephros and begin secreting testosterone in the 7th week. The Leydig cells also secrete Insulin-like 3, a protein hormone that is involved in the regulation of testicular descent.
Under the influence of testosterone, the Wolffian ducts enlarge and differentiate into the vas deferens, the epididymis and the seminal vesicles. The Mullerian ducts in the male involute in the presence of AMH.
In the female, ovarian development occurs in the absence of SRY and the presence of WNT4 and RSPO1. Germ cells migrate into the ovary and are identifiable as oocytes by 11-12 weeks. In the absence of testosterone, the Wolffian ducts atrophy and in the absence of AMH, the Mullerian ducts differentiate and grow into the uterus, the fallopian tubes and the upper two-thirds of the vagina.
Disorders of gonad formation
A rare familial form of 46,XX gonadal dysgenesis was first reported in Finland6 and found to be due to a mutation in the FSH receptor gene (for which, gene therapy is showing some promise in experimental research7). Sporadic cases may also be seen. Clinically the patient would be a phenotypic female with absent pubertal development. Features of Turner syndrome would not be found and the chromosomes would be normal. Endocrine testing would show raised levels of FSH and LH, with low levels of oestradiol. The differential diagnosis would include primary ovarian failure due to a metabolic disorder such as galactosaemia or to autoimmune endocrinopathy (which would usually occur as part of a polyglandular syndrome). Ovarian biopsy would show absence of germ cells in 46,XX gonadal dysgenesis.
Three quarters of all cases of ovotesticular DSD have a 46,XX karyotype. It is particularly common among South African black people8. It is usually associated with ambiguous genitalia. At puberty, feminization with breast development may occur. Whether or not a uterus develops will depend upon the amount of functional testicular tissue present in utero. The diagnosis of ovotesticular DSD is made according to strict criteria: testicular tissue is defined by presence of seminiferous tubules with spermatogonia, and ovarian tissue is defined by the presence of numerous primordial and/or maturing follicles within the ovarian stroma . The gonadal structure is variable, ranging from an ovary on one side and a dysgenetic testis on the other, to bilateral ovotestes. An ovotestis may have distinct ovarian and testicular poles, or the two elements may be distributed more or less uniformly throughout the gonad. The testicular components always undergo deterioration faster than the ovarian components and fertility in the male role has not been reported. Fertile ova may be produced, but even so, fertility is rare. The risk of germ cell cancer is low (but is higher in cases with a Y chromosome). Treatment would usually involve removal of the testicular component of the gonads if it was clearly demarcated, and the purpose would be to remove the source of testosterone in a person identifying as female.
Boys with this condition9 generally have normal male genitalia but may be hypogonadal and have dysgenetic testes that are small or undescended. The XX karyotype always comes as a surprise. The presence of Y-chromosome material can be detected by PCR using SRY and other probes in 80% of cases of 46,XX testicular DSD, so these cases may be considered as having a Y to X translocation and as such, are analogous to males with 47,XXY Klinefelter syndrome, who have similar clinical features. The explanation for the 20% whose PCR tests for Y chromosome sequences are negative has not yet been found. The treatment needed would include orchidopexy and in most cases, hormone replacement therapy using testosterone commencing with the induction of puberty and continuing long term. Counselling should reinforce the male gender identity and it should include an explanation that males can have a range of chromosome patterns, including XY, XXY, XYY and in some cases, XX. They are still all males.
Disorders of androgen excess
21-Hydroxylase deficiency in the classic form (apparent from birth) affects approximately 1:14,000 live births. Ninety to 95% of patients with CAH have 21-hydroxylase deficiency. It is inherited as an autosomal recessive condition, so 50% are female and 50% are male. Females with 21-hydroxylase deficiency represent the largest single group of infants born with ambiguous genitalia and 75% of them have the severe salt-wasting type which is fatal unless diagnosed and treated in a timely manner. The adrenal cortex in these salt wasting patients has less than 1% of the normal 21-hydroxylase enzyme activity and the production of both cortisol and aldosterone is severely deficient. The pituitary attempts to compensate and ACTH production is high, driving the one pathway not affected by the enzyme, which is the androgen pathway. This is why the clitoris becomes enlarged and the labia are partially fused during intrauterine life. The high levels of ACTH cause hyperpigmentation of the genital skin. After the first week of life, serum potassium starts to rise and serum sodium falls, coinciding with a fall in blood pressure due to dehydration and a risk of death due to adrenal crisis. Blood glucose may also be dangerously low. The other 25% of patients have the non-salt wasting form, and their adrenal cortex has between 1 and 3% of the normal enzyme activity. They also lose excessive salt in the urine, as indicated by a high plasma renin activity, but not enough to cause serum electrolyte disturbances or to become symptomatic. Mutational analysis of the P450CYP21 gene has revealed a large number of mutations of different types (most common of which are an intron 2 splice mutation and a group of about 9 point mutations) and there is some genotype-phenotype correlation. Girls with CAH associated with >3% enzyme activity are born with normal genitalia but may develop clitoromegaly during childhood.
The key investigation is a serum 17-hydroxyprogesterone. Levels in infants with salt wasting CAH are extremely high, and higher than those with the non-salt wasting form. Serum electrolytes and urea, blood glucose and chromosomes should also be studied. Urine steroid analysis using gas chromatography and mass spectrometry (GC-MS) is useful as a confirmatory test and it can exclude other, less common forms of CAH, such as 11b-hydroxylase deficiency.
The urogenital sinus in girls with CAH may sometimes be long and it is important when planning surgery to determine the distance between the junction of urethra and vagina and the perineum.
The treatment of CAH should be initiated and supervised long term by a paediatric endocrinologist. Initially the infant may need IV fluid, sodium chloride and glucose, at the same time as IV hydrocortisone is given. Later, oral hydrocortisone and fludrocortisone is given, with a salt supplement in the first 3-6 months of life, and these hormones are needed throughout life, with regular blood tests to monitor serum 17OHP and plasma renin activity, as well as clinical follow up to monitor linear growth, weight, blood pressure and sexual development.
Genetic counselling is highly desirable as there is a 1:4 risk of another affected child in future pregnancies, but also because prenatal diagnosis and even prenatal treatment10 with dexamethasone (to prevent the development of ambiguous genitalia in an affected female) is possible.
Psychological support from a mental health professional is considered essential for girls with CAH. Every effort needs to be made to establish good self-esteem.
Long-term outcome studies on women with CAH11 have shown that rates of sexual dysfunction - avoidance of sexual relations, painful intercourse, and inability to experience an orgasm - are high and rates of fertility are low. Most are heterosexual but there is a modest increase in those who prefer same sex relationships. A child an adolescent gynaecologist should always be involved throughout adolescence.
In resource poor settings12, girls with ambiguous genitalia due to non salt wasting CAH may not see a doctor for years and as a result, they may become extremely virilised with gross clitoromegaly, accelerated linear growth (and bone age maturation), deepening of the voice, acne and a muscular body habitus. If left long enough without treatment, they stop identifying as female and express the desire to be identified as male. Treatment of these unfortunate children is very difficult because the introduction of hydrocortisone to suppress adrenal androgens releases an already-primed hypothalamus from negative feedback and pituitary gonadotrophins are secreted, triggering central precocious puberty. The effects of this is to further curtail linear growth and the child will be a very short adult. In settings with good resources, the addition of a GnRH analogue would suppress the gonadotrophin secretion and stop the pubertal process. An even worse situation results when a girl from a very poor family has been diagnosed with CAH early in life and has then had surgery to reduce, or even remove, the clitoris, but then has poor hormone replacement therapy during childhood, and ends up as someone indentifying as male, but without a phallus.
hypertension. In the neonatal period, the blood pressure may be normal and there may even be a transient salt losing phase, so it can be difficult to make the correct diagnosis unless the investigations routinely include a urine steroid GC-MS analysis. Once the correct diagnosis is made, the appropriate treatment is hydrocortisone to suppress the ACTH and to replace the missing cortisol. Blood pressure falls as the ACTH-stimulated mineralocorticoid levels fall. The diagnostic test is serum 11-deoxycortisol, which is grossly elevated.
This is a very rare condition but an interesting one, in that it can cause the genitalia of both genetic females and of genetic males to be ambiguous. In females, the elevated levels of weak adrenal androgens such as dehydroepiandrosterone (DHEA), some of which ends up as testosterone, cause masculine changes. In genetic males, the elevated adrenal androgens are insufficient to compensate for the reduced amounts of gonadal testosterone that are secreted. The enzyme is normally expressed in both the adrenal cortex and the testis. Severe deficiency of this enzyme is also associated with salt loss and a risk of adrenal crisis.
Occasionally a pregnant woman experiences gestational virilisation (temporal hair loss, deepening of the voice, clitoral enlargement) and then gives birth to a virilised female infant. A deficiency of placental aromatase is one of the causes of this extremely rare event (other causes include maternal ingestion of androgenic medications, maternal virilizing tumour and oxido-reductase deficiency). The foetal adrenal glands normally secrete very large amounts of androgenic steroids, which cross the placenta and are aromatized to oestriol and other oestrogens. If the placenta lacks aromatase, due to a foetal genetic mutation in the CYP19A1 gene13, the unmodified foetal androgens enter the maternal circulation, cause virilisation, and are recycled back into the foetus, where the female genitalia will develop abnormally. The foetal ovaries also need aromatase to function normally, and so girls with this condition are infertile and have polycystic ovaries.
Vaginal agenesis most commonly occurs in combination with uterine agenesis, and this syndrome is known as the Rokitansky-Kustner-Hauser syndrome. The incidence is 1:4,000-1:10,000 women and the cause is unknown. Non-surgical techniques for the creation of a neo-vagina have been described and are generally successful.
Disorders of gonad formation
A typical patient with this condition would be a phenotypically normal female of normal height who had not entered puberty. Chromosomes would be done to exclude Turner syndrome and would be found to be XY. Serum FSH and LH would be very high and oestrogen levels would be low. Ultrasound would show a normal uterus but the ovaries would be too small to see – in fact, they would be streaks with few if any germ cells. The risk of germ cell cancer in these intra-abdominal streaks is high3 and laparoscopic removal of them is essential as soon as the diagnosis is made. Hormone replacement with continuous oestrogen will be needed; a progestogen would be added once breakthrough bleeding had started. Counselling should emphasize the positives, which are that women with this condition have a uterus and can therefore carry a pregnancy (but of course a donor egg would be needed). Again, the importance of the XY karyotype is not something to dwell upon as it does not define gender, but the patient has a right to know about it at an appropriate stage. All patients with this condition express a female gender identity.
In 70-80% of cases of 46,XY gonadal dysgenesis, the underlying genetic cause is unknown. Some cases have cytogenetic deletions of 9p, 2q, or 10q or duplications of 1p (WNT4) or of Xp21 [NR0B1 (DAX1)]. FISH may demonstrate a submicroscopic deletion of SRY (sex-determining region Y). In at least one family, the father (obviously unaffected) had the same SRY mutation as his 46,XY female daughter14. The application of micro-array techniques to study copy number variation has revealed duplications of NR0B1 (DAX1) or WNT4; deletions of SRY, NR5A1 (SF1), DHH; deletions of genes that map to 9p, 2q, or 10q; or other duplications or deletions.
By definition, children with partial gonadal dysgenesis (GD) have been exposed prenatally to some testosterone and are born with genitalia that are ambiguous to some degree. 46,XY gonadal dysgenesis is much less common than GD associated with sex chromosome aneuploidy (e.g 45,X/46,XY). A uterus is present in some but not all. The risk of germ cell cancer is very high3, especially if the gonad is intra-abdominal. In a streak gonad, gonadoblastoma is the premalignant condition seen, while in a better differentiated testis with seminiferous tubules, carcinoma-in-situ (CIS) is the precursor to germ cell cancer (seminoma/ germinoma).
A great deal of research has been focused on patients with XY GD, looking for mutations in genes that make up the pathway regulating testicular development, and many have been identified. Some of the mutated genes are expressed not only in the gonad, but also in other tissues. WT1, for example (the Wilms tumour suppressor gene) is expressed in the developing kidneys as well as the gonad, so patients with WT1 mutations have gonadal dysgenesis and dysplastic kidneys prone to the development of either Wilms tumour, renal failure due to glomerulosclerosis, or both. SOX9 is expressed in the skeleton as well as the developing testis, which explains why affected individuals may have the combination of campomelic dysplasia and XY gonadal dysgenesis.
Only 25% or less of cases of ovotesticular DSD have a 46,XY karyotype – the majority have 46,XX chromosomes. Experimental research in mice has shown that both 46,XY ovotesticular DSD and 46,XY gonadal dysgenesis can occur if the timing of action of Sry is disturbed very slightly5. The possibility that some human DSD could be due to variations affecting the time of onset of gene expression is an interesting one.
Disorders of androgen synthesis or action
17b-Hydroxysteroid dehydrogenase 3 (HSD17B3) deficiency causes hypogonadism in genetic males by interrupting the testicular conversion of Δ4-androstenedione to testosterone. After puberty, the ratio of Δ4-androstenedione to testosterone will be high. The administration of human chorionic gonadotrophin will be necessary to reveal this in a prepubertal child. The genitalia of an affected XY individual will generally be ambiguous. Phallic enlargement can occur before puberty. There is no uterus because the secretion of anti-Mullerian hormone is normal. Virilization takes place after puberty and some individuals raised female will develop gender dysphoria or affirm a male identity, even in cases whose testes were removed during childhood. The other DSD in which this commonly occurs is 5a-reductase 2 deficiency15. HSD17B3 deficiency has a high prevalence in the Palestinian Arab population of the Gaza Strip and the natural history has been well documented there16. Unless a good steroid laboratory is available, it can be difficult to distinguish this condition from partial androgen insensitivity syndrome. The pattern of inheritance for HSD17B3 deficiency is autosomal recessive (PAIS is an X-linked condition) but the phenotype is only seen in genetic males; affected females have no phenotype. Mutational analysis of the HSD17B3 gene will confirm the diagnosis.
See description of this condition (above) under 46,XX DSD
Deficiency of 17a-hydroxylase (a very rare condition) affects the adrenal cortex and the gonad, blocking both the cortisol and androgen pathways in the adrenal cortex, and the secretion of sex steroids by the testis or ovary. The phenotype is therefore female or ambiguous in both XY and XX individuals. In addition, there is arterial hypertension associated with hypokalaemia due to the accumulation of mineralocorticoids. The hypertension can be controlled by suppressing ACTH secretion using hydrocortisone. Affected XY individuals have no uterus because their testes secrete AMH, but XX individuals do have a uterus. Some virilisation does occur at puberty in XY individuals whose testes have not been removed and a male gender identity is possible.
The cause of lipoid adrenal hyperplasia is a mutation in the gene for the steroid acute regulatory protein (StAR)17. The StAR protein transports cholesterol across the mitochondrial membrane and in its absence, steroid biosynthesis from cholesterol cannot take place and lipoid droplets accumulate in the cytoplasm of steroidogenic cells of the adrenal cortex and gonads, making these organs enlarged and dysfunctional. The hyperplastic adrenals have a bright yellow colour. An infant born with the complete form of the condition will be phenotypically female regardless of genotype, will have ACTH-related hyperpigmentation of the skin and will develop severe adrenal insufficiency with hyponatraemia, hyperkalaemia and hypoglycaemia in the first postnatal week. Milder forms of the condition occur and patients with these can present months or years after birth with adrenal insufficiency18. Treatment with hydrocortisone and fludrocortisone leads to a good outcome. Sex hormone replacement with oestrogen at puberty is necessary for the development of secondary sex characteristics. Genetic female patients will have a uterus and will therefore need a progestogen in addition to oestrogen.
SF-1 (also known as NR5A1) is expressed in the developing adrenals, gonads and hypothalamus. A child with a complete defect in SF-1 would show failure of adrenal and gonadal development and would be born female regardless of genotype. Gonadotrophin levels would, however, be low because of a deficiency of hypothalamic GnRH.
Heterozygous SF1 mutations are much more common than was previously thought and can present as a child with penoscrotal hypospadias, micropenis and bilateral anorchia, micropenis and undescended testes, or as premature ovarian failure in an otherwise healthy girl19. In all of these examples, adrenal function has generally been normal but whether or not in the longer term adrenal insufficiency will ensue is unknown. Similarly, it is unknown if DSD or hypospadiac patients with SF-1 mutations will have normal puberty and fertility or if there is an increased risk of testicular tumors due to gonadal dysgenesis. Long term surveillance of gonadal and adrenal status is advised.
CAIS is a well known condition caused by a mutation in the androgen receptor (AR) gene, located at Xq11-q12. Infants with CAIS have a completely female phenotype, but have testes that secrete testosterone and MIS, no uterus or fallopian tubes, and a short, blind-ending vagina. The karyotype is 46,XY. The diagnosis is made either during childhood, when an inguinal hernia is found to contain a testis, or after the onset of puberty, when the girl develops breasts but no pubic or axillary hair, and there are no menses. Gender identity is always female. All tissues in the body lack the androgen receptor, including the hypothalamus, and therefore the normal negative feedback loop, in which high levels of testosterone suppress pituitary gonadotrophin secretion, does not operate. Women with CAIS have serum testosterone levels above the normal male range and it is aromatized to oestrogen. Serum LH levels are also high. Although the serum oestradiol levels exceed the normal male range, they are lower than levels in women with ovaries, and this may explain why women with CAIS are at risk of osteoporosis20. The shorter length of the vagina is a significant problem in some women and may make penetrative intercourse impossible. Generally, satisfactory lengthening of the vagina can be achieved by non-surgical dilatation methods, even by sexual activity with a patient and persistent partner. Because they have a 46,XY karyotype, women with CAIS have an average height that is taller than the average height of women.
There is an increased risk of germ cell cancer in the testes of women with CAIS21 but the risk has been revised22 and is now thought to be around 2-3%. These cancers only occur after puberty. In the past it was common for the testes to be removed in childhood ‘to prevent cancer’ but this was also in a paternalistic era when doctors were reluctant to tell parents their daughter had ‘male’ chromosomes and testes. Removing the ‘abnormal gonads’ provided a solution and avoided a difficult discussion later on. Policies of full disclosure to parents have made it easy to explain the nature of the condition to them and to involve them in formulating the risk management plan. Leaving the testes in until after puberty allows physiological breast development to take place. The recommendation to remove the testes then still stands, but even this is being questioned, given that there are other ways of checking the testes for the development of pre-malignant changes (e.g biopsy for carcinoma-in-situ), provided they are located in a superficial position. Some women request removal of inguinal testes because of discomfort and pain.
PAIS is also believed to be caused by a defect in androgen receptor function, although in the majority of cases studied, it has not been possible to identify an AR gene mutation. A few cases have been proven to have had mutations affecting various AR gene cofactors, but a mystery continues to surround the nature of many cases. At a clinical level, patients with PAIS have a highly variable phenotype, even within the one family, and not all have ambiguous genitalia or even hypospadias. At puberty, most develop significant gynaecomastia. Body hair is reduced. Positive pointers to a diagnosis of PAIS are a family history suggesting X-linked inheritance, the combination of a high serum testosterone and a high serum LH, and identification of an AR gene mutation. In the absence of the latter, other diagnoses, particularly 17b-hydroxysteroid dehydrogenase 3 deficiency or X-linked 46,XY gonadal dysgenesis, should be considered.
A study of genetically proven PAIS carried out in Baltimore23 showed that 25% of individuals had significant discomfort related to their gender as adults and some wanted surgery to change their sex. This was regardless of the initial sex of rearing. Because an unstable gender identity seems to be such a part of PAIS, any surgery should be planned in such a way that all options for the future remain open, in other words, tissue should not be removed (as in feminizing genitoplasty) when gender identity cannot be predicted. Some people advocate raising all patients with PAIS as boys and carrying out very conservative hypospadias repair. Others advocate deferring surgery until the individual has affirmed their gender identity24. The debate continues. It is clear from the evidence that an intra-abdominal testis associated with PAIS is highly likely to undergo malignant change and its removal is essential. The risk of malignancy in a scrotal or inguinal PAIS testis is lower, but still higher in than the general population, and life-long surveillance is required if it is to be retained. Biopsy after the onset of puberty to look for CIS is strongly recommended.
High-dose testosterone has been shown to bring about some penile growth in adolescents with PAIS25.
This condition is inherited as an autosomal recessive trait. The tissue levels of the enzyme 5a-reductase-2 are low, and this leads to impairment in the conversion of testosterone to the more biologically active androgen, 5a-dihydrotestosterone (DHT). Masculine development of the external genitalia is dependent on DHT, and so affected 46,XY individuals are born with ambiguous genitalia and testes. Parents often choose to raise the children as girls, but at puberty, substantial masculinization takes place, with growth of the phallus and a muscular physique, and often there is a change in gender identity from female to male. 5a-reductase-2 deficiency has been reported in many parts of the world but is rare in Caucasian people. Many different mutations in the 5a-reductase-2 gene have been identified15.
Sex chromosome aneuploidy DSD
After congenital adrenal hyperplasia, 45,X/46,XY mosaicism is the second most common cause of ambiguous genitalia. Having said that, 95% of babies identified from prenatal testing as having this karyotype are born with a normal male phenotype and two apparently normal testes26. Mixed gonadal dysgenesis refers to the presence of a streak gonad on one side and a dysplastic testis on the other. Some affected individuals have additional features of Turner syndrome (dysmorphic features, congenital heart disease, horseshoe kidney, impaired linear growth). The risk of germ cell tumours in the gonads is high. Streak gonads should always be removed at diagnosis and if it is decided to raise the child as a boy, the retained testis should be brought down to the scrotum, closely monitored throughout childhood, and biopsied for CAIS after the onset of puberty. If CAIS is detected, the testis should either be removed or irradiated.
Approximately 25% of patients with MGD have a uterus, which would allow them to bear a pregnancy (with a donated egg). This may influence the decision about sex of rearing. The risk of gender dysphoria is higher in this group than in the general population27 and more patients raised female are unhappy than those raised male. Male sex of rearing appears to be a safer option, but the decision is always a difficult one.
A detailed discussion about Turner syndrome is outside the scope of this chapter because few patients require the attention of a urologist, unless they have urinary obstruction related to a malformation of the kidneys and collecting system. The risk of cancer in the dysgenetic ovaries is low.
A small percentage of children with Klinefelter syndrome is born with ambiguous genitalia28. Klinefelter syndrome is also associated with a degree of gender instability in some patients. Although men with KS have dysgenetic testes (rarely larger than 6-10 mL) and high gonadotrophin levels, they do not appear to have a high risk of gonadal cancers. The reason for this is unclear. Men with KS do, however, have an increased of non-testicular germ cell tumours, particularly in the mediastinum, and they also have an increased life time risk of breast cancer.
Bladder extrophy and cloacal extrophy are regarded as developmental anomalies of the cloaca that have no endocrine basis. The cause is unknown.
Dysmorphic syndromes with a DSD component
Smith-Lemli-Opitz syndrome is an autosomal recessive multiple congenital malformation and mental retardation syndrome caused by a deficiency of 7-dehydrocholesterol reductase. The original description was of microcephaly, mental retardation, hypotonia, incomplete development of the male genitalia, short nose with anteverted nostrils, and pyloric stenosis.
Homozygous or compound heterozygous mutations in the gene encoding cytochrome P450 oxidoreductase (POR) on chromosome 7q11.2 can cause Antley-Bickler syndrome with disordered steroidogenesis29. The physical features of the syndrome are midface hypoplasia, choanal stenosis or atresia, multiple joint contractures, and visceral anomalies (particularly of the genitourinary system). Biochemically, there is a high ratio of metabolites of the primary adrenal steroid precursors pregnenolone and progesterone to cortisol metabolites.
46,XY individuals with mutations in the SOX9 gene may have a skeletal dysplasia, commonly lethal, combined with ambiguous or female genitalia due to gonadal dysgenesis30. The characteristic skeletal deformity is severe anterior bowing of both tibiae.
The investigation of an infant with ambiguous genitalia
Appropriate first-line investigation includes a full karyotype, which can take a number of days, but it is helpful if the laboratory can provide a rapid test to detect Y chromosome material. Where it is available, an urgently requested fluorescent in-situ hybridisation (FISH) to detect Y chromosome sequences can confirm the presence of Y chromosome material within hours. The probes used vary according to what is being looked for, starting with a centromeric probe to detect Y material in a 45,X patient and adding probes to SRY and heterochromatin when there is the possibility of a structurally altered chromosome. It should be noted that FISH is not used everywhere and many laboratories would consider a rapid high resolution karyotype to be an acceptable alternative. A pelvic ultrasound should also be urgently requested for determination of internal genitalia. It should be noted that the accuracy of this investigation is highly dependent on the skill and experience of the sonographer and the availability of small probes. Measurement of serum electrolytes, 17-hydroxyprogesterone, testosterone, follicle stimulating hormone and luteinizing hormone also constitute baseline investigations. Serum anti-Mullerian hormone is recommended but is not widely available. Further investigation is determined by the results of expert assessment and initial investigations. These may include the hCG stimulation test to assess presence of functional androgen-producing testicular tissue. The adrenocorticotrophic hormone (ACTH) stimulation test can outline a steroid hormone biosynthetic defect affecting adrenal gland as well as testis function. Urinary steroid profiling by gas chromatography and mass spectrometry can outline the level of any enzyme defect in steroid synthesis pathways, ideally using a 24 hour urine collection, but this test is not available everywhere. Detailed imaging of the internal genitalia through use of magnetic resonance imaging is used in some centres. A urogenital sinugram to outline the anatomy of the lower genital tract is useful. In some centres, gonadal biopsy to exclude pre-malignant or frankly malignant changes would be performed in infants with Y chromosome material and ambiguous genitalia, while in others, no biopsy would be performed until after the onset of puberty. Molecular genetic testing for specific gene mutations is being increasingly requested. Diagnostic algorithms are available to guide the use of these investigations but despite the increasing sophistication of investigation strategies, it is widespread experience that many infants with 46,XY DSD will be left without a precise etiological diagnosis.
Risk analysis and management
Before any surgery is undertaken, infants and children with DSD must be considered to be at risk. An infant with ambiguous genitalia, has, until proved otherwise, the risk of death or severe illness from adrenal crisis associated with congenital adrenal hyperplasia. If the infant has a Y chromosome, the risks include death in the long term from gonadal germ cell cancer. The same infant has a high likelihood of infertility and perhaps of hormone deficiency that could expose the person to the risk of osteoporosis. If the labioscrotal folds are fused, there is a risk of back-flow of urine into the vagina and recurrent urinary tract infection, that could in turn cause kidney damage. An infant with 46,XY DSD must be considered at risk of renal failure or Wilms tumour because they might have either Denys-Drash or Frasier syndrome31. Any infant with ambiguous genitalia is at risk of gender dysphoria, even gender identity disorder after reaching adolescence, or even before. The baby is at risk of being neglected by its parents, if the parents have been traumatised by the baby’s birth and not given emotional support.
Surgery exposes the child to additional risks: that the wrong operation will be done or that it will be done badly, leading to urologic damage and impaired sexual function.
Clinicians caring for infants and children with DSD are trained to assess the risks and the magnitude of the risks. In each individual case, the preparation of a risk management plan is an essential part of good management. The wide range of risks cannot be adequately covered by one person and this is why multi-disciplinary teams are able to provide the best care.
Ethical framework for decision making
Decisions about performing surgery to alter the appearance of the genitalia or to remove gonadal tissue have profound implications for the person concerned and they often need to be made long before it is possible to discern the person’s gender identity. The validity of parental consent for such procedures is being challenged and some advocates argue that a decision to operate on an infant with DSD should require authorization from a court of law. Even if this were to become the accepted practice, the ethical issues would remain. The treatment that would be in the best interests of the child would need to fulfil six ethical principles32. They are:
These principles are fully discussed elsewhere32.
General counselling and support for parents and patients
Parents are traumatized by the birth of an infant whose sex is unclear and they need the help of an experienced mental health professional, who might be a social worker or a psychologist, and who would help them to externalize their emotions, as well as discuss how best to deal with friends and relatives. It is also important to consider the family background and to identify any pre-existing risk factors, such as fragile relationships, financial difficulty, lack of support structures, substance abuse or mental illness. The treating team needs to communicate well with one another and with the parents during the period in which the sex is uncertain and while treatment is being started. Any miscommunication, especially about the sex of the baby, can cause great confusion and add to the trauma.
Surgery for ambiguous genitalia
Many operations have been devised to reduce clitoral size and the technical aspects will be discussed elsewhere. Suffice to say there has been no systematic attempt to evaluate these procedures in terms of their long term outcome results and a multi-centre and broadly based study of this kind is long overdue.
Hormonal treatment for DSD
A review of hormones used in the treatment of DSD can be found elsewhere33. Patients whose gonads have been removed or whose gonads are not secreting enough sex hormone are treated with the appropriate form of oestrogen (combined with a progestogen when a uterus is present) or testosterone. Many different preparations and modes of administration are available. Patients with adrenal insufficiency are given hydrocortisone and, if necessary, fludrocortisone.
Genetic counselling, prenatal diagnosis and treatment
All families with a child who has a DSD need genetic counselling. The counselling would include an explanation about the reason for their child’s condition and a discussion about the risk of them having another child with the same condition. In some cases, it might also lead to the identification of other unsuspected cases in the family. A child with CAIS, for example might have a younger sister or a maternal aunt with the same condition. The geneticist might be able to identify the specific mutation that caused the DSD in a child and this information might allow prenatal diagnosis in the mother’s next pregnancy, or if IVF was used, pre-implantation diagnosis and embryo selection. Couples who have previously had a child with 21-hydroxylase deficiency CAH have the option of choosing prenatal treatment with dexamethasone in the mother’s next pregnancy, aimed at preventing masculinization of the genitalia in an affected female foetus.
Women with congenital adrenal hyperplasia should have a good chance of fertility, given that their ovaries are normal, provided the genital surgery allows them to be able to have comfortable sexual intercourse. In practice, however, the fertility rates in women with salt wasting CAH are quite low, for a range of reasons34. High levels of progesterone inhibit gonadotrophin secretion. Ovaries may become polycystic. The clitoris may have lost sensitivity. The vagina may be stenosed and dry, preventing penetration. Psychologically, the woman with CAH may have either no interest in sex, or be attracted to other women.
Fertility in 46,XY DSD and sex chromosome aneuploidy DSD is rare and is usually assumed to be impossible. This assumption, however, needs to be kept under critical review and all of the advances that have been made in assisted reproductive technology should be taken into account. It would be timely to undertake a full review of the options that patients have, even considering what future developments in stem cell technology and germ cell transplantation might be able to bring. The amount of evidence about fertility in many rare conditions is far too small to form the basis for clear recommendations.
Sexual function, sexual orientation
It is unlikely that for men or women who have had genital surgery as infants or children, there is ever a perfect outcome. Many do establish satisfactory sexual relationships but it is equally clear that many do not. Professional help, for example, sexual counselling, should allow some of the difficulties that people experience to be prevented. People with atypical genitalia are unsure about how they can best achieve and give sexual pleasure. They need access to support that would help them build self-esteem and establish healthy and intimate physical relationships. The paediatric urologist, gynaecologist and psychologist or sexual counsellor need to work together to achieve the best outcome for the patient.
Gender identity, gender dysphoria, requests for sex reassignment
A technically perfect operation resulting in cosmetically excellent genitalia does not necessarily lead to a good outcome for the patient, if he or she is unable to live in the gender that was assigned at birth. It is clear that the incidence of gender dysphoria and gender identity disorder is considerably higher in DSD patients than in the general community, especially in 46,XY DSD: PAIS, 5a-reductase-2 deficiency and 17b-hydroxysteroid dehydrogenase 3 deficiency being notable examples35. Knowledge that gender dysphoria is a risk should lead surgeons to become much more conservative about performing feminizing genitoplasty, which can really only be justified in girls with CAH who have been diagnosed at birth and treated adequately from the earliest stage.
Inevitably, some patients with DSD will request sex reassignment and further surgery to reinforce this after the onset of puberty. They should be referred to a psychologist or psychiatrist familiar with gender identity disorder for a full evaluation which will need to be made carefully and over time. In Australia, a decision to proceed with any sex change surgery would require Family Court authorization because parental consent would not be considered valid. Needless to say, prevention is better than cure.
Long-term outcome studies
Our own long term outcome study of a mixed group of DSD patients whose surgical treatment was provided by a stable team of clinicians at the Royal Children’s Hospital Melbourne reported that quality of life was equivalent to that in two hospital-based control groups and that there was no evidence of major emotional problems36. Few patients reported major difficulties in sexual function. Six percent of patients were dissatisfied with their gender as adults. These results were considered to justify early genital surgery37.
Many other long term outcome studies have been published (reviewed by Warne in 200838). Conclusions drawn from these studies have varied widely, for a number of reasons. Some studies reviewed the outcome of surgery carried out by many different surgeons, using different techniques, at different centres. Not surprisingly, the results were inconsistent and in many cases, poor. Many of the studies have focused on sexual function and gender identity, rather than on overall quality of life. The risk of suicide and self-harm was highlighted by one study39.
Genital surgery is also surgery on the lower urinary tract and it is therefore not surprising that many men and also women who had genital surgery as children continue to experience significant urological and other health problems40.
Controversy, debate, legal issues related to consent
Some advocates in Australia and other countries are calling for a moratorium on genital surgery for infants with ambiguous genitalia. In Australia they have also urged governments to make it mandatory for all cases to be referred to the court for a judicial ruling. Some doctors and hospitals have been influenced by the controversy and have actually brought several cases to court, establishing in the process legal precedents that are binding on all practitioners in Australia. The key issue that is in dispute is the validity of parental consent for types of surgery that the advocates consider non-therapeutic. They argue that “cosmetic genital surgery” is not necessary for the health of the infant and can wait until the individual is able to make the decision. Few doctors accept this argument and they justify the surgery on the grounds that it prevents the psychosocial harm that would result from having to grow up with ambiguous genitalia. The debate is far from over.
Optimal management – multi-disciplinary team, clinical ethics response group, whole of life approach
The consensus guidelines for the management of DSD1 recommend that all patients should be managed by a multidisciplinary team, in a centre of excellence where the genital surgery is done by paediatric urologists. A whole of life approach is needed so that services are provided to meet the changing needs of patients as they pass through adolescence, into adult life and beyond. In the past, the needs of many patients were ignored and some adults with DSD have memories of their earlier treatment that are extremely painful and which have made it difficult for them to seek attention from doctors.
A large number of patient support groups have been established around the world. They perform very valuable roles by providing advocacy, liaison with health care professionals, pastoral care, publishing information, allowing opportunities for open-ended discussions with similarly affected people and families, lobbying and fund raising.
There are also a number of more political groups who are fighting for a cause on behalf of their members, often in opposition to traditional medical views. They deserve credit for stimulating a vigorous debate and a radical review of medical practice that is still underway.
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