{"id":4422439,"date":"2025-01-11T19:04:30","date_gmt":"2025-01-12T01:04:30","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/disorders-of-sex-development\/"},"modified":"2025-01-13T07:02:04","modified_gmt":"2025-01-13T13:02:04","slug":"disorders-of-sex-development","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/disorders-of-sex-development\/","title":{"rendered":"Disorders of Sex Development"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">DISORDERS OF SEX DEVELOPMENT (DSD)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Classification of DSD<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition<\/strong>: Congenital discrepancies between external genitalia and gonadal\/chromosomal sex.<\/li>\n\n\n\n<li><strong>Prevalence<\/strong>: Ambiguous genitalia in ~1:4000 births.<\/li>\n\n\n\n<li><strong>Three Main Categories<\/strong>:\n<ol class=\"wp-block-list\">\n<li><strong>Sex Chromosome DSD<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/turner-syndrome\/\"  data-wpil-monitor-id=\"351\">Turner syndrome<\/a> (45,X)<\/strong><\/li>\n\n\n\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/klinefelter-syndrome\/\"  data-wpil-monitor-id=\"352\">Klinefelter syndrome<\/a> (47,XXY)<\/strong><\/li>\n\n\n\n<li><strong>Mixed gonadal dysgenesis (45,X\/46,XY)<\/strong><\/li>\n\n\n\n<li><strong>Chimerism (46,XX\/46,XY)<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>46,XX DSD (Virilized XX Female)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Disorders of gonadal development (gonadal dysgenesis, ovotesticular DSD, testicular DSD)<\/li>\n\n\n\n<li>Androgen excess (fetal or maternal in origin)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>46,XY DSD (Undervirilized XY Male)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Disorders of testis development (complete\/partial gonadal dysgenesis, ovotesticular DSD, testis regression)<\/li>\n\n\n\n<li>Disorders of androgen synthesis or action (e.g., CAH, LH receptor mutations, 5\u03b1-reductase 2 deficiency)<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Components of Sex Determination<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Chromosomal Sex<\/strong> (e.g., 46,XX or 46,XY)<\/li>\n\n\n\n<li><strong>Phenotypic Sex<\/strong> (external genitalia: male or female)<\/li>\n\n\n\n<li><strong>Gonadal Sex<\/strong> (presence of ovaries or testes)<\/li>\n\n\n\n<li><strong>Psychosocial Development<\/strong> (gender identity, gender role, sexual orientation).<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>DSD<\/strong> = congenital disorder in which the development of chromosomal, phenotypic, or gonadal sex is atypical.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">CHROMOSOMAL SEX<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Usually<\/strong>: 46,XX (female), 46,XY (male).<\/li>\n\n\n\n<li><strong>Aneuploidy<\/strong>: Meiotic nondisjunction \u2192 gain\/loss of sex chromosome (e.g., 47,XXY [Klinefelter], 45,X [Turner]).<\/li>\n\n\n\n<li><strong>Mosaicism<\/strong>: Mitotic nondisjunction \u2192 45,X\/46,XX or 45,X\/46,XY, etc.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">GONADAL SEX<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Determined by <strong>presence of ovaries or testes<\/strong>.<\/li>\n\n\n\n<li><strong>Y chromosome<\/strong> has <strong>SRY<\/strong> (testis-determining gene); it + <strong>SOX9<\/strong> \u2192 testis development, AMH production \u2192 m\u00fcllerian duct regression.<\/li>\n\n\n\n<li><strong>Ovarian development<\/strong>: Absence of SRY\/SOX9 expression and lack of AMH secretion \u2192 normal female internal duct formation.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PHENOTYPIC SEX<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Male Differentiation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Sertoli cells<\/strong>: Produce <strong>AMH<\/strong> \u2192 m\u00fcllerian duct regression (uterus, fallopian tubes, upper vagina).\n<ul class=\"wp-block-list\">\n<li>If AMH or its receptor is defective \u2192 Persistent M\u00fcllerian Duct Syndrome (PMDS).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Leydig cells<\/strong>: Secrete androgens (testosterone) by 9th week.\n<ul class=\"wp-block-list\">\n<li>Stimulated first by hCG (1st\u20132nd trimesters), then by fetal LH (3rd trimester).<\/li>\n\n\n\n<li>Testosterone stabilizes wolffian duct structures (vas deferens, epididymis, seminal vesicles).<\/li>\n\n\n\n<li><strong>DHT<\/strong> (via 5\u03b1-reductase type 2) \u2192 <a href=\"https:\/\/myendoconsult.com\/learn\/male-external-genitalia-exam\/\"  data-wpil-monitor-id=\"356\">male external genitalia<\/a> (penis, scrotum).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Testicular Descent<\/strong>: Two stages\u2014transabdominal (~12 wks) and transinguinal (androgen + LH dependent).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Female Differentiation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>M\u00fcllerian ducts<\/strong> \u2192 uterus, upper vagina, fallopian tubes in absence of testicular factors.<\/li>\n\n\n\n<li><strong>Wolffian ducts<\/strong> regress without local testosterone.<\/li>\n\n\n\n<li><strong>External Genitalia<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Genital tubercle \u2192 clitoris.<\/li>\n\n\n\n<li>Urogenital folds \u2192 labia minora.<\/li>\n\n\n\n<li>Urogenital swellings \u2192 labia majora.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Ovarian estrogen is minimal in fetus; female ductal development does not require gonadal hormones.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Psychosocial Development<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Gender identity, gender role, sexual orientation<\/strong> are influenced by prenatal hormone levels + postnatal environment.<\/li>\n\n\n\n<li>Example: <strong>Complete <a href=\"https:\/\/myendoconsult.com\/learn\/androgen-insensitivity-syndrome\/\"  data-wpil-monitor-id=\"353\">Androgen Insensitivity Syndrome<\/a> (CAIS)<\/strong> (46,XY) \u2192 typical female psychosocial development.<\/li>\n\n\n\n<li>Some changes may occur at puberty (e.g., 5\u03b1-reductase deficiency).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">SEX CHROMOSOME DISORDERS OF SEX DEVELOPMENT<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Klinefelter Syndrome (47,XXY)<\/strong>: <\/li>\n\n\n\n<li><strong>Turner Syndrome (45,X)<\/strong>:<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Mixed Gonadal Dysgenesis (45,X\/46,XY)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Phenotypic Range<\/strong>: From typical female external genitalia to ambiguous or typical male.<\/li>\n\n\n\n<li><strong>Gonadal Range<\/strong>: Streak gonads to normal testes.<\/li>\n\n\n\n<li><strong>Uterus<\/strong> may be present if AMH is insufficient \u2192 persistent m\u00fcllerian structures.<\/li>\n\n\n\n<li><strong>Management<\/strong>:\n<ul class=\"wp-block-list\">\n<li>If raised as girl (with minimal virilization), remove dysgenic gonads (high tumor risk), then start estrogen therapy at puberty.<\/li>\n\n\n\n<li>If raised as boy (hypospadias, partial testis function), then hypospadias repair, orchiopexy if needed, possibly testosterone at puberty.<\/li>\n\n\n\n<li>In very ambiguous cases, complex decisions are made with a multidisciplinary team.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Chimerism (46,XX\/46,XY)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Results from double fertilization or ovum fusion.<\/li>\n\n\n\n<li>Can lead to <strong>ovotesticular DSD<\/strong> (true hermaphroditism).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">46,XX DISORDERS OF SEX DEVELOPMENT<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>(Virilized XX Female)<\/strong><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Main Causes<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Gonadal Dysgenesis<\/strong> (primary ovarian failure, minimal estrogen).<\/li>\n\n\n\n<li><strong>Ovotesticular DSD<\/strong> (ovary + testis tissue).<\/li>\n\n\n\n<li><strong>Testicular DSD<\/strong> (SRY translocation, SOX9 duplication).<\/li>\n\n\n\n<li><strong>Androgen Excess<\/strong> (most common):\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/congenital-adrenal-hyperplasia-cah\/\"  data-wpil-monitor-id=\"354\">Congenital Adrenal Hyperplasia<\/a> (CAH)<\/strong>, typically 21-hydroxylase deficiency.<\/li>\n\n\n\n<li><strong>Gestational hyperandrogenism<\/strong> (e.g., maternal androgen-secreting tumor, theca-lutein cysts, placental aromatase deficiency).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Congenital Adrenal Hyperplasia<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Most frequent cause of <strong>virilized XX newborns<\/strong> (46,XX DSD).<\/li>\n\n\n\n<li>Usually 21-hydroxylase deficiency.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Ovotesticular DSD (True Hermaphroditism)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Presence of both testicular and ovarian tissue<\/strong> in one or both gonads.<\/li>\n\n\n\n<li>Typically 46,XX karyotype (~60%), less commonly 46,XX\/46,XY chimeric.<\/li>\n\n\n\n<li>Gonads can be: ovotestis on one side + ovary\/testis on other, bilateral ovotestes, or testis on one side + ovary on the other (least common).<\/li>\n\n\n\n<li>External phenotype can vary from near male to near female; many have ambiguous genitalia.<\/li>\n\n\n\n<li>Management: Complex; depends on functional aspects, tumor risk, potential fertility, and desired gender assignment.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">46,XY DISORDERS OF SEX DEVELOPMENT<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>(Undervirilized XY Male)<\/strong><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Main Causes<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Abnormal Testis Development<\/strong>\n<ul class=\"wp-block-list\">\n<li>Complete or partial gonadal dysgenesis (e.g., Swyer syndrome).<\/li>\n\n\n\n<li>Ovotesticular DSD.<\/li>\n\n\n\n<li>Testis regression (e.g., vanished testis syndrome).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Impaired Androgen Synthesis<\/strong>\n<ul class=\"wp-block-list\">\n<li>CAH due to 17\u03b1-hydroxylase deficiency, 3\u03b2-HSD deficiency, P450scc deficiency.<\/li>\n\n\n\n<li>LH receptor defects (Leydig cell hypoplasia).<\/li>\n\n\n\n<li>5\u03b1-reductase 2 deficiency \u2192 inadequate DHT \u2192 undervirilized external genitalia.<\/li>\n\n\n\n<li>17\u03b2-HSD type 3 deficiency (most common testosterone synthesis defect).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Impaired Androgen Action<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Androgen Insensitivity Syndrome (AIS)<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Complete (CAIS) \u2192 phenotypic female with undescended testes, no uterus, no pubic\/axillary hair.<\/li>\n\n\n\n<li>Partial (PAIS) \u2192 ambiguous or predominantly male or female with some undervirilization.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Mutations in AR gene; range of clinical phenotypes.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical Presentation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ranges from ambiguous genitalia, micropenis, hypospadias to near-female external appearance.<\/li>\n\n\n\n<li>Gonads may be undescended (risk of tumors).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">EVALUATION AND TREATMENT OF DSD<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Initial Workup<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>History<\/strong>: Family occurrences, maternal exposures, prior pregnancies.<\/li>\n\n\n\n<li><strong>Physical Exam<\/strong>: External genitalia measurements (phallus size, fused labial\/scrotal tissue), presence of gonads in labia\/inguinal canal, TANNER staging if older.<\/li>\n\n\n\n<li><strong>Laboratory<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Serum electrolytes (to rule out salt-wasting CAH).<\/li>\n\n\n\n<li>17-hydroxyprogesterone, cortisol, DHEA, androstenedione, testosterone, LH, FSH, TSH.<\/li>\n\n\n\n<li>\u00b1 \u03b2-hCG, \u03b1-fetoprotein if germ cell tumor suspected.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Karyotype<\/strong> + <strong>FISH<\/strong> for SRY gene.<\/li>\n\n\n\n<li><strong>Imaging<\/strong>: Pelvic and abdominal ultrasound \u2192 uterus\/vagina presence, gonad location\/size.<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Management Implications<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Determine underlying cause<\/strong>: Key for deciding sex assignment, surgical interventions, hormone treatments, tumor risk.<\/li>\n\n\n\n<li><strong>Sex Assignment<\/strong>: Typically guided by the probability of future gonadal function, potential fertility, surgical complexity, and psychosocial considerations.<\/li>\n\n\n\n<li><strong>Hormone Therapy<\/strong>: E.g., glucocorticoid for CAH, GnRH analog for central <a href=\"https:\/\/myendoconsult.com\/learn\/topics\/precocious-puberty\/\"  data-wpil-monitor-id=\"355\">precocious puberty<\/a> if relevant.<\/li>\n\n\n\n<li><strong>Surgical<\/strong>: Gonadectomy of dysgenic gonads (tumor risk), correction of ambiguous genitalia (urogenital sinus anomalies), orchiopexy for undescended testis, or hypospadias repair.<\/li>\n\n\n\n<li><strong>Long-Term Follow-Up<\/strong>: Involves endocrinologists, surgeons, geneticists, psychologists for counseling on fertility, psychosocial identity, risk of neoplasms, etc.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>DISORDERS OF SEX DEVELOPMENT (DSD) Classification of DSD Components of Sex Determination DSD = congenital disorder in which the development of chromosomal, phenotypic, or&hellip;<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[685],"class_list":["post-4422439","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-reproductive-disorders"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422439","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":5,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422439\/revisions"}],"predecessor-version":[{"id":4422874,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422439\/revisions\/4422874"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422439"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}