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A person’s sex is affected by genetic, hormonal and psychosocial factors. In this context, one can distinguish the chromosomal, gonadal and phenotypic sex on the biological side, and the gender role and identity on
the other side. Discrepancies between the chromosomal, gonadal and phenotypic sex are referred to as intersexuality. The chromosomal sex is determined at the time of conception; the gonadal sex is determined by the
development of the genital glands, or gonads; the phenotypic differentiation of the primary and secondary sexual characteristics is regulated by hormones. Usually, sexual identity develops during the first 14 months
of life but it can still change at a later time, depending on biological and psychosocial factors. Both autosomal genes and genes on the gonosomes play a role here. Disorders in the genes for development can lead to
disorders of gonadal development, subsequently impeding or impairing hormone production and thus influencing the phenotypic sex, resulting in intersexuality and maybe uncertainty about sexual identity.
In
contrast to disorders of gonadal development with a ubiquitous change in the hormone environment, there are on the other hand also specific defects in steroid biosynthesis, which can lead to an excess or lack of
certain metabolites. The androgen receptor defect, in which the effect of androgenic steroids is impeded, is a special case. The gene for the androgen receptor has been identified on the X chromosome. A large number
of mutations of this gene have been described in connection with androgen insensitivity. However, so far there are only very incomplete explanations for the often high variability in the genotype-phenotype
correlation in sexual differentiation disorders. Primary genetic phenomena, such as postzygotic mutation accompanied by the formation of somatic mosaicism, may play a crucial role in androgen receptor defects.
Beyond this, there is evidence suggesting that the interaction between various key enzymes involved in androgen biosynthesis and the androgen receptor, may be decisive in determining the
clinical phenotype. This is particularly true also for the supply of the various steroid hormone metabolites such as androstenedione, testosterone and dihydrotestosterone, which transmit different effects via the
receptor. The identification of androgen-regulating genes will be crucial in order to help understand the regulatory mechanism downstream from the receptor.
Sexual identity, gender role behaviour and sexual
orientation in human beings are influenced by the above-mentioned biological factors, and to a considerable extent also modified by psychological, social and cultural factors. The phenomenon of a lack of
identification with the assigned sexual identity (gender identity disorder), which occurs distinctly more often in intersex people than within the normal population, to the point of desiring to change their sex,
suggests that various different factors must contribute towards the development of an individual’s sexual identity. In particular, the prenatal exposure to androgens, but also to other steroids, seems to play an
important role in imprinting the human brain. This is confirmed, among other things, by research on sex-specific children’s play, which proves to be strikingly stable in spite of the changing socialisation in
modern societies. At the moment, however, there is only a scant understanding of the role played by genetic factors that are independent of the sex chromosomes, by prenatal and postnatal hormonal factors, by social
sex assignment, preferences within the environment, early childhood identification and interaction processes, or social learning.
While progress in molecular genetic and endocrinological research over recent
years has considerably contributed towards an etiological clarification of sexual differentiation disorders, the specific diagnosis and prognosis for individual patients always remains difficult. In particular at
the birth of a child with an abnormal external genitalia, the urgent question often arises, though very difficult to answer, as to the correct sexual assignment, as well as the indication for and possible sequence
of surgical interventions or hormone treatment. Since the 1950s, the early and extensive correction of the external genitalia by paediatric surgical, urological and gynaecological experts has been recommended –
initially by Money and coworkers at the Johns Hopkins University and later by other centres too – based on the assumption that the core sexual identity is fully developed by the 24th month of a child’s life. In
particular, it was recommended that children with a micropenis be raised as girls, since it was assumed that a penis that was too small or that was inadequate for vaginal intercourse would make identification with a
male gender role impossible, and lead to social stigmatisation. This approach was thought to save parents from uncertainty and give them confidence in bringing up the child. However, this concept – also adopted in
Germany – has been the subject of criticism over recent years: critics believe that the insecurity and in particular the sense of shame is in fact induced precisely by doctors seeking ‘normalisation’. The
long-term success of early reconstructive interventions has been called into question by long-range studies. Considerable insecurity is also apparent in terms of informing the child itself and counselling the
family, with increasing criticism of the previously common practice of not telling children about their intersexuality or their deviant chromosomal sex. Many patients report considerable traumatisation as a result
of the treatment process, in particular the shame of being different, but also shame about the repeated medical examinations associated with the surgery, and about the surgery itself and the consequences, as well as
the loss of the capacity for sexual experiences. One possible long-term effect under discussion is post-traumatic stress disorders (PTSD), which many of those affected do indeed report suffering from. Follow-up
examinations of intersex children have shown that in 39% of those concerned, psychopathological findings also had to be ascertained. Self-reporting by intersex patients, media reports, the foundation of self-help
groups (especially in the USA, more recently also in Germany) and ethical disputes within the medical profession have led to a debate, heated at times, as to the best approach in the interest of the children
concerned. This debate is taking place in the context of questions about the right of sexual self-determination, personal autonomy, “informed consent” and the relationship between doctors and their patients.
However providing the appropriate information and obtaining the consent of the patients and their parents are made very difficult by the fact that long-term results of treatment are completely lacking. Where they
are nevertheless attempted, family counselling is based on the personal experiences of the medical professionals, or on casuistic observations.
In view of the heterogeneity in the aetiology, phenomenology and
therapeutic interventions, intersex patients are looked after by a large number of medical disciplines (paediatricians, internists, endocrinologists, gynaecologists, paediatric surgeons, general surgeons and
urologists, as well as a range of psychotherapeutic or social services). In the studies to date, the psychological aspect has been confined to the simple question, what the individual is, and what he or she likes to
play. The lack of interaction between the various disciplines involved means that it is often difficult to find a team of cooperating experts for the particular problems of a specific child, or to inform patients
and their parents comprehensively. Experiences in the UK and the USA show that a support group of affected individuals can be an important source of support and advice for others. However it is no substitute for
expert psychological care. The demand for “evidence-based medicine” calls for the critical examination and evaluation of treatment outcomes, outcomes which include not only the success of somatic aspects, e.g.
surgical treatment, but all aspects of quality of life and the psychosexual development of the individuals concerned.
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