“Male pseudohermaphroditism” is an outdated clinical label that has been formally replaced by “46,XY disorders of sex development” (46,XY DSD). The change was driven by a 2006 international consensus recognizing that the old terminology was medically imprecise, confusing, and stigmatizing to patients and families. Under the newer system, the karyotype itself serves as the organizing prefix, so conditions once lumped under “male pseudohermaphroditism” are now classified as 46,XY DSD, while conditions formerly called “female pseudohermaphroditism” became 46,XX DSD.1PubMed. Disorders of sex development: a new definition and classification The shift in language was more than cosmetic. It reflected a broader rethinking of how clinicians approach these conditions, from diagnosis through long-term care.
Why the Old Term Was Abandoned
The word “hermaphrodite” traces back to Greek mythology, and its medical usage carried connotations that many patients and families found dehumanizing. “Pseudohermaphroditism” was particularly confusing because it implied a false version of something most people already misunderstood. The prefix “male” referred to the 46,XY karyotype, not to the person’s appearance or identity, which created a mismatch that was disorienting for families hearing their child’s diagnosis for the first time.
The 2006 Chicago Consensus, organized under the Lawson Wilkins Pediatric Endocrine Society and the European Society for Paediatric Endocrinology, proposed a karyotype-based system specifically to eliminate these problems. A survey evaluating the new terminology found that roughly 86% of participants preferred “DSD” over “intersex,” and parents of affected children had an even higher preference at about 95%.2Journal of Pediatric Urology. Evaluation of terminology used to describe disorders of sex development Parents reported that the newer terms helped them understand their child’s condition and explain it to relatives. Health professionals, meanwhile, tended to favor the genotype-based subcategories (like 46,XY DSD) for their clinical specificity. The term “DSD” itself has drawn some criticism from intersex advocacy groups who prefer identity-affirming language, but it remains the dominant framework in clinical medicine.
How Fetal Sex Development Works, and Where It Diverges
To make sense of 46,XY DSD, it helps to understand the basics of what happens during fetal development. The process unfolds in three broad stages: first, an undifferentiated period when XX and XY embryos have identical reproductive structures; second, the gonads begin to differentiate into either testes or ovaries; and third, the internal and external genitalia develop under the influence of gonadal hormones.3Elsevier / PubMed Central. Normal male sexual differentiation and aetiology of disorders of sex development In a typical 46,XY fetus, the SRY gene on the Y chromosome triggers the gonads to become testes, which then produce testosterone and other hormones that drive masculinization of the body.
46,XY DSD occurs when something disrupts one or more of those stages. The disruption can happen at many points: the gene that triggers testis formation might not function, the testes might form but fail to produce adequate hormones, the hormones might be produced but not converted into their active forms, or the body’s tissues might not respond to the hormones at all. Each of these breakdowns produces a different clinical picture, which is why 46,XY DSD is not a single condition but an umbrella covering many distinct diagnoses.
Gonadal Dysgenesis
One major category of 46,XY DSD involves problems with gonad formation itself. In gonadal dysgenesis, the testes either fail to develop entirely (complete gonadal dysgenesis, sometimes called Swyer syndrome) or develop only partially (partial gonadal dysgenesis). The result is that the gonads produce little or no testosterone, so the body does not masculinize during fetal development. People with complete gonadal dysgenesis typically have female-appearing external genitalia and are often not diagnosed until puberty fails to occur on its own.
The genetic roots are diverse. Mutations in testis-determining genes like SRY, SF1, and SOX9 have been identified in patients with 46,XY gonadal dysgenesis.4PLoS ONE. Failure of SOX9 Regulation in 46XY Disorders of Sex Development with SRY, SOX9 and SF1 Mutations Other genetic culprits include mutations in FOG2/ZFPM2, WT1, and deletions on chromosome 9p.5PubMed. Genetic mutations and somatic anomalies in association with 46,XY gonadal dysgenesis In many cases, though, the specific genetic cause is never identified, which reflects how much remains unknown about the full genetic architecture of gonad development.
Androgen Insensitivity Syndrome
Perhaps the best-known form of 46,XY DSD is androgen insensitivity syndrome (AIS). In AIS, the testes form and produce testosterone normally, but the body’s cells cannot respond to it because of mutations in the androgen receptor gene on the X chromosome. The spectrum of effects ranges dramatically: complete androgen insensitivity (CAIS) produces entirely female-appearing external genitalia, while partial forms (PAIS) produce a wide range of genital appearances, and mild forms may present only as infertility in an otherwise typical-looking male.6PubMed. Androgen insensitivity syndrome: clinical features and molecular defects
Over 600 different mutations in the androgen receptor gene have been documented, affecting either its ability to bind DNA or its ability to bind androgens, or introducing premature stop signals that truncate the receptor protein entirely.7Molecular and Cellular Endocrinology. Molecular basis of androgen insensitivity This molecular diversity helps explain the wide phenotypic spectrum. People with CAIS are typically raised female, identify as female, and often learn of their diagnosis only when they are evaluated for absent menstruation or discovered to have undescended testes during an unrelated medical procedure.
Enzyme Deficiencies That Block Masculinization
Several enzyme deficiencies can interrupt the hormonal cascade needed for masculinization, each with its own distinctive pattern.
5-alpha reductase type 2 deficiency prevents the conversion of testosterone to dihydrotestosterone (DHT), the more potent androgen required for full development of external genitalia. The condition is caused by mutations in the SRD5A2 gene and produces a broad range of appearances at birth, from female-appearing to male-appearing genitalia with everything in between.8PubMed Central. Phenotype, Sex of Rearing, Gender Re-Assignment, and Response to Medical Treatment in Extended Family Members with a Novel Mutation in the SRD5A2 Gene A hallmark of this condition is significant virilization at puberty, when rising testosterone levels partially compensate for the missing DHT, sometimes causing dramatic physical changes in individuals who had been raised as girls. The classic presentation was historically described as “pseudovaginal perineoscrotal hypospadias,” another term that has fallen out of use.9American Journal of Medical Genetics. 10PubMed. Pitfalls in hormonal diagnosis of 17-beta hydroxysteroid dehydrogenase III deficiency Like 5-alpha reductase deficiency, 17β-HSD3 deficiency is inherited in an autosomal recessive pattern, meaning both copies of the HSD17B3 gene must carry mutations.11PubMed. 17Beta-hydroxysteroid dehydrogenase-3 deficiency: diagnosis, phenotypic variability, population genetics, and worldwide distribution of ancient and de novo mutations Affected individuals often present with predominantly female-appearing genitalia at birth and, like those with 5-alpha reductase deficiency, may virilize substantially at puberty.
Rarer Causes
Leydig cell hypoplasia is a rare condition where the cells in the testes responsible for producing testosterone are underdeveloped or absent. Because testosterone production is impaired at its source, affected 46,XY individuals can present with a range of undermasculinized phenotypes. The condition is linked to defects in the LH receptor gene (LHCGR), though genetic analysis does not always identify a mutation.12PubMed Central. LEYDIG CELL HYPOPLASIA: A UNIQUE PARADOX IN THE DIAGNOSIS OF 46,XY DISORDERS OF SEX DEVELOPMENT.
Persistent Müllerian duct syndrome (PMDS) is a different kind of problem entirely. In typical male development, anti-Müllerian hormone (AMH) causes the Müllerian ducts (which would otherwise become the uterus and fallopian tubes) to regress. In PMDS, either AMH itself is deficient or its receptor is defective, so these structures persist in an otherwise male-appearing individual. PMDS is usually discovered incidentally during surgery for an undescended testis or inguinal hernia.13PubMed Central. Persistent Müllerian duct syndrome: A case report and review
How 46,XY DSD Is Diagnosed
Diagnosis typically begins when ambiguous genitalia are noticed at birth, when expected puberty does not occur, or when an incidental finding surfaces during unrelated medical care. The workup involves a combination of physical examination, hormone measurements, imaging, and increasingly, genetic testing.
Hormonal evaluation often includes a human chorionic gonadotropin (hCG) stimulation test. This test checks whether testicular tissue is present and functional by administering hCG injections and measuring how testosterone levels respond. Specific hormone ratios help distinguish between conditions: the ratio of testosterone to DHT can point toward 5-alpha reductase deficiency when it’s elevated, while the ratio of androstenedione to testosterone helps flag 17β-HSD3 deficiency.14PubMed Central. Clinical, hormonal and radiological profile of 46XY disorders of sexual development In suspected 5-alpha reductase deficiency, stimulated testosterone-to-DHT ratios above 10 are considered strongly suggestive, though values below that threshold do not necessarily rule it out.15Endocrine Abstracts. The value of the stimulated testosterone: dihydrotestosterone ratio in 46, XY DSD due to 5alpha-reductase type 2 deficiency
Genetic testing has transformed the diagnostic landscape. Traditional approaches relied on testing one gene at a time based on clinical suspicion, which was slow and often inconclusive. Next-generation sequencing panels that screen dozens of DSD-related genes simultaneously have significantly improved diagnostic yield. One study found that a panel approach identified a likely molecular diagnosis in about 28% of patients, roughly three times the rate of the prior single-gene testing strategy.16Scientific Reports. Diagnostic Application of Targeted Next-Generation Sequencing of 80 Genes Associated with Disorders of Sexual Development Another research group reported confirmed diagnoses in about a third of their 46,XY DSD patients using a similar approach, with mutations found across genes including AR, SRD5A2, HSD17B3, AMH, AMHR2, NR5A1, and WT1, many of which led directly to changes in patient management.17PubMed Central. Next generation sequencing (NGS) to improve the diagnosis and management of patients with disorders of sex development (DSD) Even so, a substantial proportion of 46,XY DSD cases remain without a definitive genetic explanation, underscoring how many contributing genes likely remain undiscovered.
Gonadal Tumor Risk
One of the most clinically consequential aspects of 46,XY DSD is the elevated risk of gonadal tumors, particularly germ cell tumors. The risk varies dramatically depending on the specific underlying diagnosis. Dysgenetic gonads carry the highest risk: germ cell tumors have been reported in roughly 20 to 30% of individuals with 46,XY DSD involving gonadal dysgenesis.18Journal of Clinical Research in Pediatric Endocrinology. The Evaluation of Cases with Y-Chromosome Gonadal Dysgenesis: Clinical Experience over 18 Years The most common tumor type in this group is gonadoblastoma, a generally benign tumor that can, however, give rise to invasive malignancies like dysgerminoma or seminoma.
A large study of 292 patients with various 46,XY DSD diagnoses found an overall germ cell tumor risk of about 15%, with pure gonadal dysgenesis carrying the highest risk at about 23%. Complete androgen insensitivity syndrome came next, while conditions like mixed gonadal dysgenesis and 17-alpha hydroxylase deficiency had risks below 10%.19PubMed. Gonadal tumour risk in 292 phenotypic female patients with disorders of sex development containing Y chromosome or Y-derived sequence These risk differences matter enormously for clinical decisions about whether and when to remove gonads. In high-risk conditions like complete gonadal dysgenesis, early gonadectomy is often recommended. In CAIS, where tumor risk is lower and the gonads provide a natural source of estrogen, the decision is more nuanced, with many clinicians and patients opting to defer gonadectomy until after puberty.
The Debate Over Early Genital Surgery
Few topics in DSD care generate more passionate disagreement than the question of genital surgery in infancy. For decades, the prevailing medical approach was to surgically “normalize” ambiguous genitalia early in life, usually to align with the sex of rearing. The rationale was that early surgery would spare children from social stigma and help solidify gender identity. But this approach came under sharp criticism from patient advocates, ethicists, and human rights bodies who argued that irreversible surgery performed without the patient’s consent violated their rights to bodily integrity and self-determination.
International human rights authorities within the United Nations, the Council of Europe, and the European Union have identified nonconsensual gender-conforming interventions on children with intersex conditions as violating children’s rights to bodily integrity, privacy, and protection from degrading treatment.20Medical Law Review. Protecting the Rights of Children with Intersex Conditions from Nonconsensual Gender-Conforming Medical Interventions: The View from Europe This growing international consensus has been reinforced by advocacy organizations and legal scholars who call for prohibiting non-consensual medical interventions on intersex persons.21PubMed Central. Intersex care in the United States and international standards of human rights
Current expert recommendations from the European Reference Network for Endocrine Conditions (ENDO-ERN) advocate deferring nonurgent surgeries with irreversible effects until the individual can provide informed consent, while strengthening family support systems and promoting standardized multidisciplinary care.22European Journal of Endocrinology. ENDO-ERN expert opinion: addressing the endocrine needs in considering genital surgery in disorders/differences in sex development individuals in Europe In practice, this means that medically necessary procedures (like creating a urinary opening) may still happen early, but purely cosmetic genital surgeries are increasingly postponed. The shift is far from universal, though. Practices vary widely between countries, between hospitals, and even between individual surgeons.
Fertility and Reproductive Potential
Fertility is often assumed to be impossible for people with 46,XY DSD, but the reality is more nuanced. While many individuals with these conditions do face significant reproductive challenges, research has shown that some gonads in DSD patients retain reproductive potential. Advances in fertility preservation, particularly cryopreservation of testicular tissue, are beginning to open doors that were previously closed. Successful outcomes with ovarian tissue cryopreservation in other contexts have encouraged researchers to explore similar approaches for testicular tissue, and cryopreservation is now being offered to boys before cancer treatment as a proof of concept.23PubMed. Establishing reproductive potential and advances in fertility preservation techniques for XY individuals with differences in sex development For individuals with DSD whose gonads are removed for medical reasons (such as tumor risk), preserving tissue before gonadectomy is an area of active investigation, though it remains largely experimental.
Mental Health and Psychosocial Impact
Living with a DSD condition takes a significant psychosocial toll, and the legacy of the old terminology is part of that burden. A national study of intersex adults in the United States found strikingly high rates of mental health difficulties: about 63% reported a history of anxiety disorders, roughly 61% reported depressive disorders, and around 41% reported post-traumatic stress disorder. Nearly a third of participants reported a previous suicide attempt.24PubMed Central. A national study on the physical and mental health of intersex adults in the U.S. These numbers are far higher than general population averages and reflect a combination of factors: the stress of growing up with a body that doesn’t match societal expectations, the trauma of unwanted medical interventions in childhood, secrecy and shame imposed by families or physicians, and the challenge of navigating a world built around a rigid gender binary.
Younger participants in the study reported higher rates of anxiety than older ones, a pattern consistent with broader generational trends in mental health but also likely shaped by changing norms around disclosure and identity. The shift away from stigmatizing terminology like “pseudohermaphroditism” is part of a larger cultural and clinical effort to reduce shame and secrecy, though language alone cannot undo the structural problems that drive poor mental health outcomes.
Environmental Endocrine Disruptors
Most cases of 46,XY DSD have a clear genetic basis, but environmental factors can contribute as well. Certain chemical pollutants, including organochlorine pesticides, polychlorinated biphenyls, dioxins, phthalates, and some plant-derived compounds, can mimic estrogens or block androgens. When a pregnant woman is exposed to high levels of these endocrine disruptors, fetal male sexual differentiation can be disrupted. A screening program identified newborns with ambiguous genitalia whose mothers had been exposed to environmental pollutants during pregnancy, and the newborns’ blood showed elevated estrogenic activity, strongly suggesting a link between the exposure and the genital differences.25PubMed. Increased serum estrogenic bioactivity in three male newborns with ambiguous genitalia: a potential consequence of prenatal exposure to environmental endocrine disruptors Environmental cases like these are thought to be uncommon compared to genetic causes, but they raise important questions about the reproductive effects of widespread chemical exposure, questions that extend well beyond the DSD population and into broader public health discussions about endocrine-disrupting chemicals in everyday life.