Dysgenesis of the sexes (DSD), formerly known as hermaphroditism, is a congenital developmental abnormality or mismatch of chromosomes, gonads, and phenotypic sexes, with limited data on its prevalence, and an overall prevalence rate of approximately 1/4500-1/5500.Congenital adrenocortical hyperplasia (CAH) and mixed gonadal hypoplasia are the two most common etiologic factors for ambiguous external genitalia, accounting for more than 50 percent of cases of ambiguous external genitalia in the neonatal period. external genitalia in more than 50% of cases. The worldwide prevalence of these two diseases is 1:15,000 and 1:10,000, respectively, but the prevalence varies in different populations. Clinical typing: according to the chromosomal karyotype is divided into three major types, and each type is further divided into different types according to different etiologies. (1) Abnormal gonadal (ovarian) development: including ovotesticular DSD, 46XX male (testicular DSD), simple gonadal hypoplasia (2) Androgen excess: including fetal causes: CAH (21-, 11-hydroxylase deficiency is the most common, and 3β-hydroxysteroid dehydrogenase 2 deficiency); maternal causes: luteinoma of pregnancy, exogenous drugs; placental causes: aromatase deficiency, P450 oxidoreductase (POR) deficiency; (3) other causes: cloacal ectopia, vaginal atresia, Mullerian duct, kidney, cervicothoracic segmental dysplasia (MURCS), other rare syndromes. 2. 46XYDSD: (1) abnormal gonadal (testicular) development: complete gonadal hypoplasia (Swyer syndrome, also known as 46XY female), partial gonadal hypoplasia, bilateral testicular disappearance or degeneration syndrome, ovotesticular DSD; (2) Leydig cell dysplasia (LH receptor defect); (3) abnormal androgen synthesis: 17,20-cleaving enzyme deficiency, 17β-hydroxysteroid oxidoreductase, 17β-hydroxysteroid oxidoreductase deficiency, 17β-hydroxysteroid oxidoreductase deficiency, 17β-hydroxysteroid oxidase, 17β-hydroxysteroid oxidase; and other rare syndromes. hydroxysteroid oxidoreductase (type 3) deficiency, male CAH (cholesterol side-chain cleaving enzyme StAR deficiency, cytochrome P450 oxidoreductase POR deficiency, 3β-hydroxysteroid dehydrogenase deficiency, 17α-hydroxylase deficiency); (4) androgen receptor and post-receptor deficiencies: complete and mild androgen insensitivity syndrome; (5) testosterone metabolism in peripheral tissue (5) Abnormal metabolism of testosterone in peripheral tissues: 5α reductase deficiency; (6) Abnormal synthesis and secretion of anti-Mullerian duct inhibitory substance (AMH) or its receptor: Mullerian duct perpetuation syndrome; (7) Others: severe hypospadias, cloacal exstrophy. Sex chromosome DSD: (1) 45X (Turner syndrome and variants); (2) 47XXY (Klinefelter syndrome and variants); (3) 45X/46XY (mixed gonadal dysgenesis, ovotesticular DSD); (4) 46XX/46XY (chimerism, ovotesticular DSD). Clinical presentation: Patients of different ages often present for different reasons. Newborns are often seen for the following reasons: prominent ambiguous external genitalia, marked female external genitalia with clitoromegaly, or posterior labial fusion, or inguinal/labial masses, marked male external genitalia with bilateral undescended testes, or micropenis, or a single perineal hypospadias, or mild hypospadias combined with undescended testes, family history of CAIS, and inconsistency between external genital phenotype and karyotype. Reasons for consultation in older children include the presence of ambiguous external genitalia not originally recognized, inguinal hernia in girls, delayed or incomplete puberty, primary amenorrhea or masculinization in girls, mammary gland development in boys, and microscopic or periodic hematuria in boys. Diagnosis: 1, ask detailed family history and maternal pregnancy history; 2, physical examination: focus on external genitalia and special signs of endocrine diseases; 3, laboratory tests: determine the chromosomal karyotype, serological testing of various hormone levels, DNA analysis of special gene mutations, hCG stimulation test, ACTH excitation test, GnRH stimulation test; 4, imaging tests: ultrasound, reproductive tract photographic imaging, Pelvic MRI, etc. 5, diagnostic exploration surgery: if after laboratory and imaging tests still can not determine the diagnosis and the nature of the gonads, it is necessary to carry out gonadal exploration, the nature of the gonads is not clear need to carry out a gonadal biopsy. Treatment: (1) Non-surgical treatment; (1) Children with CAH first need systematic treatment in pediatric endocrinology; (2) Hormone replacement therapy: For those whose gonadal function is insufficient to initiate puberty and maintain secondary sexual characteristics, systematic endocrine therapy is needed before puberty; (3) Psychotherapy: From neonatal to adulthood, regular sexual, psychological and social support can enable DSD patients to obtain good long-term results. Surgical treatment: (1) sex determination; (2) external genital plastic surgery: male external genital plastic surgery: correction of penile recurvature, reconstruction of the urethra, scrotal molding, testicular fixation, etc.; female external genital plastic surgery: to retain the dorsal vascular and nerve bundles of the clitoris as well as the head of the clitoris clitoridoplasty, vaginoplasty and labiaplasty. Summary: Gender dysphoria cannot be judged solely on the basis of the first impression of the external genitalia, and more than half of DSD patients cannot be diagnosed even after detailed examination and evaluation. The first step is to make a definitive diagnosis through a detailed history, physical examination, laboratory and imaging tests, and if necessary, surgical gonadal exploration, and then the parents or the patient will make the decision to determine an appropriate sex for rearing after they have been fully informed about the condition and the related knowledge. Long-term follow-up and psychological interventions are required after surgery.