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Presentation on theme: "DISORDERED SEXUAL DIFFERENTIATION"— Presentation transcript:


2 TERMINOLOGY Ambiguous genitalia New term: complex genital anomaly
Ambiguous genitalia = external phenotype is sufficiently abnormal to cause uncertainty as to which gender should be assigned Complex genital anomaly – more descriptive than ambiguous genitalia and does not have same unfortunate connotation and therefore is the preferred term

3 EMBRYOGENESIS Sex determination Sex differentiation
Transcription and translation of genetic code to direct formation of ovary or testis within urogenital ridge Sex defferentiation: Follows sex determination Dependent upon the stimulation, production, recognition of hormones from the gonads to complete development of the internal and external genital structures. Completed by 12 weeks gestation

4 Presence of sex-determinaing region of Y chromosome (SRY) instructs bipotential gonad to develop into a testis. If no Y chromosome present but 2 X chromosomes the bipotential gonads forms an ovary (both X chromosomes needed for ovarian survival) Testis and ovary consist of supporting cells (sertoli, granulosa cells) Hormone producing cells (leydig, theca) Germ cells (spermatozoa and ova) Primordial germ cells migrate from wall of yolk sac and enter primary sex cords to develop into ova and sperm Murran K, Segal D (2009) Disorderd sexual differentiation (Ambiguous genitalia: an appraoch to diagnosis and management. South African Paediatric Review Volume 6 no 3: 20-30

5 Development of internal gonads results from a paracrine effect from the ipsilateral gonad.
TESTOSERONE from Leydig cells of the testis is responsible for ipsilateral Wolffian duct stabilization (high levels of LOCAL testosterone is needed for stabilization of Wollfian duct Therefore high systemic levels of androgen seen in female fetuses with CAH and maternal androgen exposure do NOT result in male internal genitalia) MULLERIAN INHIBITING SUBSTANCE from Sertoli cells causes regression of the ipsilateral mullerian structures. In ABSENCE OF TESTOSTERONE AND MIS default pathway is that of female differentiation with formation of ovary and persistence of mullerian structures. Murran K, Segal D (2009) Disorderd sexual differentiation (Ambiguous genitalia: an appraoch to diagnosis and management. South African Paediatric Review Volume 6 no 3: 20-30

6 Presence or absence of androgen determines the final sex differentiation of external genitalia.
1st trimester: testosterone production is under stimulation of placental human chorionic gonadotropin (hCG) and later under the stimulation of fetal ptuitary derived lutenizing hormone (LH). 5 alpha reductase enzyme in cytoplasm of cells of external genitalia and urogenital sinus convert testosterone into dihydrotestosterone (DHT) much more potent steroid than testosterone which acts through androgen receptor to complete the process of male external genital differentiation. After 15 weeks testosterone exposure results in elongation of the phallus. In the absence of this androgen effect, female external genitalia develop Murran K, Segal D (2009) Disorderd sexual differentiation (Ambiguous genitalia: an appraoch to diagnosis and management. South African Paediatric Review Volume 6 no 3: 20-30

7 APPROACH History Clinical Special investigations

8 HISTORY Detailed family history
Prenatal exposure to exogenous or endogenous androgens, estrogens or potential endocrine disruptors Maternal virilization during pregnancy Detailed family history – unexplained infant deaths (as infants with CAH could have died prior to diagnosis), consanguinity and infertility Many DSD autosomal recessive inheritance Ask about gynecomastia and infertility (may represent milder phenotypes for some DSD) X-linked disorders eg androgen insensitivity – may be affected maternal family members eg amenorrhoea, infertile aunts or partially virilized uncles

9 EXAMINATION General examination – dysmorphisms
Examination of external genitalia Phallus Phallus – measure phallic length, if less than 2.5cm is considered as micropenis - clitoris length longer than 1 cm is abnormal - measure phallic bredth.

10 EXAMINATION Orifices Labioscrotal folds Gonads
Orifices – position of urethral meatus and vaginal orifice Labioscrotal folds – look at assymetry Gonads – note size and consistency

11 INVESTIGATIONS Genetics – 46XX, 46XY, 46 XY/X0
Hormones (see cholesterol pathway) - 17 OH progesterone - DHEA - Androstendione - Testosterone level GENETICS – 46XX most likely overvirilized female or true hermaphrodite - 46XY undervirilized male, true hermaphrodite or testicular dysgenesis - 46 XY/X0 gonadal dysgenesis

Electrolytes Ultrasound Laparoscopy Electrolytes important to determine if infant is salt wasting Ultrasound is the preferred mode of imaging Genitograms done at specialized centres, useful in determining if there is vagina and to outline the uterine canal and follopian tubes Further laparoscopy done for visualisation and biopsy of gonads may be required

13 MANAGEMENT Team approach - Family doctor - Paediatric endocrinologist
- Surgeon - Geneticist - Social worker - Psychologist Involve child and parents

14 GENDER ASSIGNMENT Based on - specific pathophysiology
- prognosis for spontaneous pubertal development - potential for sexual activity - potential for fertility - endocrine function - parental wishes Psychosexual development Psychosexual development - Gender identity – begins as infant with self-recognition as boy or girl - Gender role – develops during childhood as result of society’s expectations concerning behaviour and is influenced by prenatal hormonal exposure - Sexual orientation Process and need to be considered carefully

Medical emergency - do test stat and inform the parents what the diagnosis is - pros and cons Decide gender later and let child decide - Decide gender later and child involved in decision - Pros and cons Medical emergency - positives: have definitive gender for all before they leave the hospital greater surgery success Gender later - positives: have a say in the gender assignment - negatives: Smaller surgical success – technical, phallus enlargement cannot be stimulated by testosterone after puberty

16 SURGERY Surgical treatment of complex genital anomalies is controversial Specific surgical procedures at specific stages dependent on gender assignment Specific surgical procedures - Clitorophallic reduction towards female gender - Hypospadias repair (most difficult) - Vaginal reconstruction - Gonadectomy

1. Overvirilization of female fetus (46 XX DSD) 2. Undervirilization of male fetus (46 XY DSD) 3. True hermaphrodite (or ovotesticular DSD) 4. Gonadal dysgenesis

Congenital adrenal hyperplasia – not difficult to diagnose Autosomal recessive Leads to deficiency in enzyme function in the cortisol and aldosterone pathways Most common 21 hydroxylase (21OH) deficiency Reduced negative feedback from cortisol on ptuitary gland causes increase in ACTH which leads to adrenal hypertrophy Enzyme blockage leads to deficient production of adrenal hormones in affected pathways with overproduction along remaining pathways. Deficient aldosterone production leads to salt wasting and deficient cortisol production and adrenal crisis. Over production of androgens: DHEAS, androstendione and testosterone lead to virilization. Clue to diagnosis is low serum Na and high K.

19 Congenital adrenal hyperplasia
Girl: - present with ambiguous genitalia - low Na , High K - eventually becomes dehydrated Boy - presents with dehydration and hyperkalaemia - normal genitalia therefore no clue to diagnosis

46 XY Defect in testosterone production Defect in testosterone metabolism Defect in testosterone action Defect in testosterone production – Leydig cell hypoplasia / agenesis OR enzyme defect in testosterone biosynthesis Defect in testosterone metabolism – 5 alpha reductase deficiency Defect in testosterone action – androgen insensitivity syndrome

21 TRUE HERMAPHRODITE Ovotesticular Disorder of sexual diffirentiation
Common in central and southern Africa. Both ovarian and testicular tissue present. Diagnosis confirmed on biopsy of gonads Outcome regarding fertility has been disappointing Ovotesticular DSD should be suspected when there is evidence of testicular tissue in presense of Mullerian structures

22 GONADAL DYSGENESIS Spectrum of disorders that lead to the maldevelopment of the gonads and subsequently varying degrees of Disorders of Sexual differentiation

23 REFERENCES Raine J, Donaldson MDC, Gregory JW, Savage MO, Hintz RL (2006) Practical Endocrinology and Diabetes in Children Murran K, Segal D (2009) Disorderd sexual differentiation (Ambiguous genitalia: an appraoch to diagnosis and management. South African Paediatric Review Volume 6 no 3: 20-30 Wiersma R True hermaphroditism in southern Africa: the clinical picture Pediatr Surg Int (2004) 20: Sperling (2008) Ambiguous genitalia. Paediatric Endocrinology 3rd Edition: APPROACHES TO GENDER ASSIGNMENT


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