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Disorders of Sexual Development (DSDs) are a group of congenital conditions in which chromosomal, gonadal, or anatomical sex development is atypical. They encompass a spectrum of phenotypes with discrepancies among genetic sex (karyotype), gonadal sex (ovary/testis), and phenotypic sex (external genitalia).
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https://www.youtube.com/watch?v=sVCJtQKPUno
2006 Chicago Consensus classification:
| Category | Karyotype | Definition |
|---|---|---|
| 46,XX DSD | 46,XX | Individuals with female karyotype and disorders leading to virilization |
| 46,XY DSD | 46,XY | Individuals with male karyotype and under-virilization or feminization |
| Sex Chromosome DSD | 45,X / 47,XXY / 45,X/46,XY | Abnormalities of sex chromosomes (e.g., mosaicism) |
Schematic describing sex chromosome involvement of disorders of sexual development.
Rothkopf AC, John RM. Understanding Disorders of Sexual Development. Journal of Pediatric Nursing. 2014;29(5):e23-e34. doi:https://doi.org/10.1016/j.pedn.2014.04.002
Classification of DSD based on karyotype and diagnostic category leading to a specific diagnosis: This classification uses a genetic approach to characterize differences of sex development (DSD) as recommended in the Chicago Consensus 2005 AMH, anti-Müllerian hormone; MRKH, Mayer–Rokitansky–Küster–Hauser; MURCS, Müllerian duct aplasia, renal aplasia, cervicothoracic somite dysplasia; SCA, sex chromosomal anomalies.
Differences of sex development. Nat Rev Dis Primers 11, 55 (2025). https://doi.org/10.1038/s41572-025-00644-z
Female genotype with male/ambiguous phenotype
| Cause | Features |
|---|---|
| ‣ (most common) | Excess androgens; ambiguous genitalia, clitoromegaly, fused labia; uterus present |
| Maternal androgen exposure | Placental aromatase deficiency, virilizing tumors |
| ‣ (rare) | Presence of both ovarian and testicular tissue; varying phenotype |
Male genotype with female/ambiguous phenotype
| Cause | Features |
|---|---|
| ‣ | Complete: female phenotype, no uterus, undescended testes; Partial: ambiguous genitalia |
| ‣ | Impaired DHT synthesis → ambiguous genitalia; virilization at puberty |
| Gonadal dysgenesis (‣ ) | Streak gonads, uterus present, no pubertal development |
| ‣ | Testosterone production failure; female external genitalia, undescended testes |
| Condition | Karyotype | Features |
|---|---|---|
| ‣ | 45,X | Short stature, streak ovaries, amenorrhea, horseshoe kidney |
| ‣ | 47,XXY | Tall male, small testes, gynecomastia, infertility |
| Mixed gonadal dysgenesis | 45,X/46,XY | One testis + one streak gonad; ambiguous genitalia |
| Ovotesticular DSD | Various | Ovarian + testicular tissue; very rare; ambiguous genitalia |