Disorders of sex development


Disorders of sex development, also known as differences in sex development, variations in sex characteristics, sexual anomalies, or sexual abnormalities, are congenital conditions affecting the reproductive system, in which development of chromosomal, gonadal, or anatomical sex is atypical.
DSDs are subdivided into groups in which the labels generally emphasize the karyotype's role in diagnosis: 46,XX; 46,XY; sex chromosome; XX, sex reversal; ovotesticular disorder; and XY, sex reversal.
In the cases when a baby is born with an atypical anatomical sex, families often experience confusion and distress. Sexual and psychological developpement are influenced by numerous factors that include, but are not limited to, gender differences in brain structure, genes associated with sexual development, prenatal androgen exposure, interactions with family, and cultural and societal factors. Because of the complex and multifaceted factors involved, communication and psychosexual support are all important.
A team of experts, or patient support groups, are usually recommended for cases related to sexual anomalies. This team of experts are usually derived from a variety of disciplines including pediatricians, neonatologists, pediatric urologists, pediatric general surgeons, endocrinologists, geneticists, radiologists, psychologists and social workers. These professionals are capable of providing first line and second line diagnostic tests to examine and diagnose sexual anomalies.

Overview

DSDs are defined as "any problem noted at birth where the genitalia are atypical in relation to the chromosomes or gonads". There are several types of DSDs, and their effect on the external and internal reproductive organs varies greatly.
A frequently used, casual social adjective for people with DSDs is "intersex". Urologists were concerned that terms like intersex, hermaphrodite, and pseudohermaphrodite were confusing and pejorative with respect to humans. This led to the Chicago Consensus, recommending a new terminology based on the umbrella term disorders of sex development. However, intersex people have continued to prefer the term "intersex" over "DSD" by large margins. Other than disorders of sex development, another term is congenital conditions of sex development. Since 2006, people who were previously incorrectly categorized as hermaphrodites are now labelled as having ovotesticular syndrome.
DSDs are divided into the following categories, emphasizing the karyotype's role in diagnosis:
The penis and clitoris have a common origin, both arising from an embryonic structure called the primordial phallus. In typical males, the urethra is located at the tip of the penis, while in typical females the urethra is located below the base of the clitoris. It is also possible to have a urethral opening located along the shaft; this condition is known as hypospadias.

Management of DSDs

Due to the significant and life-long impacts that DSDs can have on patients and their families, it is widely accepted that children with DSDs should be managed by an experienced multidisciplinary team. Health care providers generally agree that children with DSDs should be notified early.
Appropriate and conservative medical intervention and age-appropriate child involvement in the treatment plan contribute greatly to successful outcomes for the entire range of DSDs.

Key hormones

In the normal prenatal stages of fetal development, the fetus is exposed to testosterone - albeit more in male fetuses than female ones. Upon the presence of the 5α-reductase enzyme, testosterone is converted to dihydrotestosterone. If DHT is present, the male external genitalia will develop.
Development of male external genitalia:
On the other hand, if maternal placenta estrogen is present without DHT, then the development of female external genitalia occurs.
Development of female external genitalia :
However, in abnormal cases, sexual anomalies occur due to a variety of factors that lead to an excess of androgens in the fetus. The effects of excessive androgens differ in fetuses with XX chromosome and XY chromosomes.
In XX chromosome fetuses, excess androgens result in ambiguous genitalia. This makes identification of external genitalia as male or female difficult. Additionally, the individual may have clitoromegaly, a shallow vagina, early and rapid growth of pubic hair in childhood, delayed puberty, hirsutism, virilisation, irregular menstrual cycle in adolescence and infertility due to anovulation.
In XY chromosome fetuses, excess androgens result in a functional and average-sized penis with extreme virilisation, but the inability for sperm production. Additionally, the individual will also experience early and rapid growth of pubic hair during childhood and precocious puberty stages.

Causes

Sexual anomalies often generate from genetic abnormalities caused by many factors, leading to different sexual development. These genetic abnormalities occur during the prenatal stage of an individual's fetal development. During this stage, genetic mutations can result from endocrine disrupters in the mother's diet or environmental factors. The general causes of sexual anomalies can not be outlined due to the high variability of each individual's situations. Thus, the cause of each specific anomaly has to be studied independently.
Sexual differentiation occurs through various processes during the prenatal development period of the fetus. These processes are initiated and regulated by biological metabolites such as DNA, hormones and proteins. The initial steps of sexual differentiation begin with the development of the gonads and genitals. This process is consistent with both genders spanning over the course of the first 6 weeks following conception, during which the embryo remains pluripotent. Differentiation of the gonads begins after the 6th week, which is determined by the sex-determining region Y gene in the Y chromosome.
The SRY gene plays an important role in developing the testes of a male individual. Following the development of the testes, hormones synthesized within the testes regulate the differentiation of both internal and external parts of the genitals. The absence of the testicles or the hormones synthesized may lead to irregular differentiation of the genitals. Genetic abnormalities or environmental factors that influence these procedures may lead to the incomplete development of the gonads and the genitals. These malformations can occur any time during the development or the birth of the embryo, manifesting as ambiguous genitals or dissonance within the genotypic and phenotypic sex of the individual, leading to a late onset of puberty, amenorrhea, a lack of or excess virilization, or later in life, infertility or early occurrence of menopause.

Chromosomal variation

DSDs caused by chromosomal variation generally do not present with genital ambiguity. This includes sex chromosome DSDs such as Klinefelter syndrome, Turner syndrome and 45,X or 46,XY gonadal dysgenesis.
Males with Klinefelter syndrome usually have a karyotype of 47,XXY as a result of having two or more X chromosomes. Affected patients generally have normal genital development, yet are infertile and have small, poor functioning testes, breast growth and delayed puberty. The incidence for 47,XXY is 1 in 500 males, but severe and rare cases of Klinefelter syndrome presents as three or more X chromosomes.
Turner syndrome is classified as aneuploidy or structural rearrangement of the X chromosome. Signs and symptoms of affected females vary among them, such as low birth weight, low-set ears, short stature, short neck and delayed puberty. The incidence is 1 in 2,500 live-born females, while most patients do not survive for more than one year after birth.

Gonadal development disorders

Gonadal development disorders form a wide spectrum, classified by their cytogenetic and histopathological features. However, unsolved diagnosis and malignancy still represent difficulties in the sex determination of these patients. Such disorders include partial or complete gonadal dysgenesis, ovotesticular DSD, testicular DSD and sex reversal.

Abnormal genital development

Genital abnormality can occur in the penis, scrotum or testes in males; and vagina and labia in females. Sometimes, ambiguous genitalia could occur, where the clear distinction of external genitalia is absent in both male and female. Hence, examination is carried out where the sex of the patient will be determined through imaging and blood tests. Abnormal genital development includes disorders of fetal origin, disorders in androgen synthesis or action, disorders in anti-Müllerian hormone synthesis or action.

Others

In addition to the aforementioned sexual anomalies, there are other unclassified sexual anomalies. In males, this includes severe early-onset intrauterine growth restriction, isolated hypospadias, congenital hypogonadotropic hypogonadism, hypogonadism and cryptorchidism. In females, this includes Malformation syndromes, Müllerian agenesis/hypoplasia, uterine anomalies, vaginal atresia and labial adhesions.

Conditions

First line diagnostic tests (prenatal)

Family history

  • Symptoms such as infertility, early menopause, amenorrhea or sudden infant death syndrome could be a sign. Hence, an early check-up should be conducted.

    Analysis of karyotype

  • Peripheral blood is collected for karyotyping. This helps classify the patient in one of the three main categories of DSD: chromosomal variation, gonadal development disorders and abnormal genital development.

    Abdominal ultrasounds

  • The presence of gonads, uterus and vagina should be monitored. This can be done through abdominal ultrasounds. However, the absence of these sex organs will lead to difficulties in gender identification.

    Second line diagnostic tests (postnatal)

Physical examination

  1. Inspection of the genitalia with care and palpation must be conducted with the following points in mind.
  2. * Determining the degree of virilization or masculinisation:
  3. ** In a female fetus, the Prader scale should be used to assess the extent of the virilisation if the karyotyping results are not out yet.
  4. ** In males, the external masculinization score should be used.
  5. Palpation of gonads from the labioscrotal fold to the abdomen.
  6. Hydration and blood pressure assessment should be conducted.
  7. Additional dysmorphic features should be ruled out because genitalia malformations would occur if the patient has multiple malformation syndromes.

    Evaluation of hormones 48 hours after birth

  • 17-Hydroxyprogesterone can be used to screen for congenital adrenal hyperplasia . This is commonly found in patients with 46, XX DSD.
  • Dehydroepiandrosterone in addition to progesterone allows for the diagnosis of more uncommon forms of CAH and other inherited disorders.
  • Base testosterone, follicle stimulating hormone and luteinising hormone levels are precursors in individuals with 46,XX DSD. These tests are conducted within the timeframe of thirty hours post-birth to anywhere between fifteen and ninety days post-birth. This data collected within time frame can be used to gauge the growth of the fetus when it reaches six months of age.
  • Basal cortisol levels and adrenocorticotropic hormone is essential in diagnosing panhypopituitarism and enzymatic disorders affecting adrenal steroidogenesis.
  • The anti-Müllerian hormone is used for evaluating the function of Sertoli cells.
  • A urinary steroid profile shows the ratio of precursor metabolites within measured urine concentrations and the resultant products produced indicates the enzyme is the cause of a sexual defect. This is a more specific procedure in the detection of the defect in comparison to analysing blood.

    Treatment and management

The treatment and/or management of DSDs with atypical genitalia will vary from person to person. This may include gender affirmation surgery, medical treatment and surgical treatment.

Gender affirmation surgery

Gender affirmation plays a critical role in the management of sexual anomaly cases. Ultimately, the parents and a multidisciplinary team are responsible for assigning the sex that is affirmative the gender of the concerned person. The current guidelines of gender affirmation include the psychosocial effects in adults with etiological diagnosis, the potential for fertility, surgical opportunities and hormone replacement therapy in the course of puberty.
There are other factors considered during this process. This may include cultural and religious factors as well as the implications it has on the individual in later life. It is regulated by reference centers with groups specialised in managing cases of sexual anomalies.

Medical treatment

Hormonal treatment is an accepted and standardised approach to treat different congenital sexual anomalies. Patients that are deficient in hormones produced by the adrenal glands require immediate medical attention. They are given a hormone called hydrocortisone, a form of hormone replacement therapy, with the objective to induce puberty.
Utilizing sex steroids as hormonal therapy is deemed controversial with concerns of its duration of initiation, dosage and regimen. However, it is agreed amongst most clinicians that low doses of hormonal treatment should begin around the age of 11 to 12 years old and should be increased progressively.

Surgical treatment

Surgical procedures are an alternative to hormonal treatment available for patients to address genital anomalies and improve the body's sexual functions. However, a common dilemma in these procedures is that they are often derived from the patient's expectation of 'normal' genitals from an aesthetic and functional standpoint. Oftentimes, this leads to extensive surgical interventions.
In most cases, surgical procedures result in permanent changes to the appearance and function of the patient's body. Therefore, the decision to proceed with this arrangement must be a joint agreement between the family and the multidisciplinary team. The most ideal situation would be to include the patient as part of the decision-making process. However, cases where surgical treatments were performed at an early age are recognised as mutilation of the body. Subsequently, it has become increasingly common to defer surgical treatments until the patient is of appropriate age to be involved in the decision-making process.

Organizations

Clinical networks and organizations

DSD-TRN

The Differences of Sex Development-Translational Research Network is based in the United States and aims to improve DSD care across the United States.

I-DSD

The International-Differences of Sex Development is a research organization in Europe. This organization connects medical and research centers internationally in an effort to improve clinical practice, research, and general understanding of differences of sex development. I-DSD regularly hosts a symposium to provide updates on current care in DSD internationally, facilitate networking for those in DSD Care, and promote high quality DSD research.

Patient support and advocacy organizations

Notable patient support and advocacy organizations include:

Controversy

Even though the term disorder of sex development is widely accepted by the medical community, its suitability and adequacy to represent these individuals are criticised by many support and advocacy groups. Firstly, the word 'disorder' carries negative connotations. Secondly, with current nomenclature, DSD is an overly generalised term for conditions that do not have differences in genital appearance or gender identity. Thirdly, the term 'DSD' lacks specificity and clarity; and therefore unhelpful in the diagnosis process. Hence, many support groups and advocates believe that the medical community should discontinue the use of 'DSD' as a designation tool.
Furthermore, people who live with conditions regarding sexual abnormalities may encounter various mental and physical health problems. This may include traumatic experience with their own bodies, dissatisfaction with body image, low-self esteem, anxiety, depression, bipolar disorders, eating disorders, personality disorders, schizophrenia disorders, trauma and stress-related disorders, etc.
Many intersex people are engaged in activism to stop hormonal treatments, citing the extreme and harmful nature of many of the treatments, further arguing that many of the treatments serve no medical purpose.

Terminology

The term disorders of sex development has generally been accepted by the medical community, as well as being a popular term in academic literature. However, the term is not universal among patients or support groups. One study stated that it can affect individuals covered by the description in a negative way, and that the terminology might impact choice and utilization of health care providers. Another study found that most affected individuals did not find the term offensive. The ICD-11, which is the World Health Organization's international guide to medical coding, references DSDs as intersex traits or conditions, as do some medical journals. The Council of Europe and Inter-American Commission on Human Rights have called for a review of medical classifications that unnecessarily medicalize intersex traits.
The DSD as a model was advocated for by intersex advocates to include all variation of atypical sexual development. Specifically the DSD exists as replacement for the "optimum gender rearing model," which was the standard model for individuals with atypical sexual development. This model stated goal was to assign a gender binary, usually female via non-consensual medicalization, often via the falsification of medical records. After the publication of individuals who had undergone the OGR model and had gone through serious physiological distress,, the model was discredited. The term "disorders of sexual development" was chosen to reflect the variation of sexual development over differences which effects all individuals, this however has been controversial, with many instead opting for "differentiation" or "variation."
Sociological research in Australia on 272 "people born with atypical sex characteristics," published in 2016, found that 3% of respondents used the term "disorders of sex development" or "DSD" to define their sex characteristics, while 21% use the term when accessing medical services. In contrast, 60% used the term "intersex" in some form to self-describe their sex characteristics. U.S. research by the Lurie Children's Hospital, Chicago, and the AIS-DSD Support Group published in 2017 found that "disorders of sex development" terminology may negatively affect care, give offense, and result in lower attendance at medical clinics.
A "dsd-LIFE" study in 2020 found that around 69% of 1,040 participants reported that DSD applied to their condition or that they felt neutral about the term, with most participants preferring terms that were specific to their somatic condition.

Human rights and community concerns

The term DSD has been controversial. The argument over terminology reflects a deeper disagreement over the extent to which intersex conditions require medical intervention, the appropriateness of certain interventions, and whether physicians and parents should make irreversible treatment decisions on behalf of young children if the condition is not life-threatening.
  • Use of the term disorder of sex development is controversial among many activists and community organizations due to the label "disorders". Many governments and international institutions use the term 'intersex' in preference to 'DSD', or have called for the review of medical classifications. In May 2019, more than 50 intersex-led organizations signed a multilingual joint statement condemning the introduction of "disorders of sex development" language into the International Classification of Diseases, stating that this causes "harm" and facilitates human rights violations, calling on the World Health Organization to publish clear policy to ensure that intersex medical interventions are "fully compatible with human rights norms".
  • Lee et al. in a 2006 Consensus statement on management of intersex disorders proposed a system of nomenclature based on "disorders of sex development" for clinical use, suggesting that "terms such as intersex, pseudohermaphroditism, hermaphroditism, sex reversal, and gender based diagnostic labels are particularly controversial," may be perceived as pejorative, and are confusing to practitioners and parents alike. However, research by the Lurie Children's Hospital, Chicago, and the AIS-DSD Support Group published in 2017 found that affected persons, and care givers, object to the term, and that this may impact choice, access, and utilization of health care providers. Australian sociological research on people born with atypical sex characteristics, published in 2016, found that 3% of respondents choose the term "disorders of sex development" or "DSD" to define their sex characteristics, while 21% use the term when accessing medical services. In contrast, 60% used the term "intersex" in some form to self-describe their sex characteristics.
  • A committee of the Senate of Australia found that labelling intersex as "pejorative" appeared to be a post-hoc rationalisation in the 2006 Consensus statement. It recommended a review of clinical use of the term.
  • Alternative terms have been offered: Milton Diamond has suggested the use of "variation" or of "difference", Elizabeth Reis has suggested "divergence"; Liao and Simmonds suggest "diverse sex development". The latter suggestions would retain the initial D in DSD.
  • The 2006 Consensus statement on management of intersex disorders stated that evidence for early surgery for cosmetic reasons is lacking, outcomes include "decreased sexual sensitivity" and long term outcome data is absent. A 2016 Global Disorders of Sex Development Update since 2006 states that there is "still no consensual attitude regarding indications, timing, procedure and evaluation of outcome of DSD surgery" and "no evidence regarding the impact of surgically treated or non-treated DSDs during childhood for the individual, the parents, society or the risk of stigmatization".
  • In 2013, Juan E. Méndez, the United Nations Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment, condemned "irreversible sex assignment, involuntary sterilization, involuntary genital normalizing surgery, performed without their informed consent, or that of their parents, 'in an attempt to fix their sex'" stating that "members of sexual minorities are disproportionately subjected to torture and other forms of ill-treatment because they fail to conform to socially constructed gender expectations".
  • In May 2014, the World Health Organization issued a joint statement on Eliminating forced, coercive and otherwise involuntary sterilization, An interagency statement with the OHCHR, UN Women, UNAIDS, UNDP, UNFPA and UNICEF. Referencing the involuntary surgical "sex-normalising or other procedures" on "intersex persons", the report recommends a range of guiding principles for medical treatment, including ensuring patient autonomy in decision-making, ensuring non-discrimination, accountability and access to remedies.
  • During 2015, the Council of Europe and Inter-American Commission on Human Rights called for a review of medical classifications that may unnecessarily medicalize intersex traits, an end to medical interventions without consent, and improved disclosure. The Council of Europe's Human Rights Commissioner recommended:
  • The European Union Agency for Fundamental Rights and UN Treaty Bodies have called for informed consent by individuals subjected to medical treatment, improved disclosure, and access to redress.

    Clinical disagreements about the term

While the 2006 clinical consensus statement that introduced the term, its 2016 update, included some sex chromosome anomalies within the term DSD, the inclusion of those conditions is opposed by some clinicians. Medical historian David Griffiths has identified continued controversy about the relationship between sex chromosome variations and intersex/DSD classifications.
Similarly, some clinicians have proposed that congenital adrenal hyperplasia be excluded. Human rights advocate Morgan Carpenter has remarked that this proposal appears motivated by support for contentious medical interventions.
A member of the legal committee for the World Professional Association for Transgender Health and co-founder of the Australian and New Zealand Professional Association for Transgender Health has described "transsexualism" as "an intersex condition and a disorder of sexual development therapeutically medically treated by hormonal therapy and Genital Reassignment Surgery". Such views are contested.

People with DSDs competing in sporting events

There is particular contention around female-presenting athletes with DSDs competing in female-only sports events.
World Athletics claimed that while 46 XY DSD occurs in roughly 1 in 20,000 people in the general population, it is found in about 7 in 1,000 elite female athletes arguing that this offers significant performance advantage. Within the scientific community there is ongoing debate over whether any physiological advantage, in fact, exists.