A review of the essential concepts in diagnosis, therapy, and gender assignment in disorders of sexual development

Annals of Pediatric Surgery

Table 1 The aetiological classification of DSD

Etiology	Type	Subtypes
A. Sex chromosomal DSD
	Turner’s syndrome, XO	Variants
	Klinefelter’s syndrome, XXY	Variants
	Mixed gonadal dysgenesis, XO/XY
	Ovotesticular DSD, XX/XY
	SR + 46 XX testicular DSD
B. Disorders of gonadal development
	46 XY complete gonadal dysgenesis
	46 XY partial gonadal dysgenesis
	46 XY ovotesticular DSD
	Testicular regression syndrome
	46 XX pure gonadal dysgenesis
	46 XX ovotesticular DSD
C. Abnormalities in phenotypic sex secondary to hormonal defects
a. 46 XY DSD	Defects in androgen synthesis	Leydig cell hypoplasia, testosterone biosynthesis defects, 5-alpha reductase deficiency
	Defect in androgen action	Androgen insensitivity syndrome (complete/partial)
	Defect in AMH synthesis or action	Persistent Mullerian duct syndrome
b. 46 XX DSD	Disorders of genital development due to androgen excess
	1. Fetal origin	Congenital adrenal hyperplasia (CYP21A2 deficiency, CYP11B1 deficiency, etc.)
	2. Fetoplacental origin	Aromatase deficiency, androgen secreting tumors
	3. Maternal origin	Drugs/virilizing tumors
D. Primary endocrine abnormalities
	Central endocrine dysfunction	Congenital hypogonadotropic hypogonadism, pan-hypopitutarism
E. Malformation syndromes	Associated with external genital anomalies	Persistent Cloaca, cloacal exstrophy, MRKH syndrome/Mullerian agenesis, vaginal atresia

46 XY DSD male pseudohermaphrodite, under-virilized male; 46 XX DSD female pseudohermaphrodite, androgenized female; True hermaphrodite ovotesticular DSD; 46 XX testicular DSD XX male/XX sex reversal; 46 XY complete gonadal dysgenesis XY sex reversal