The document discusses ambiguous genitalia or intersex conditions. It defines ambiguous genitalia and provides classifications based on karyotype and etiology. Key causes include congenital adrenal hyperplasia, androgen insensitivity syndrome, and true gonadal intersex. The document outlines approaches to diagnosis, including family history, physical exam, imaging, hormonal testing, and biopsy. Determining the karyotype, presence of uterus, and hormone levels helps to differentiate between conditions like hermaphroditism versus disorders of sex development.
1. Ambiguous Genitalia
( Hermaphroditism )
Definition –
The term ambiguous genitalia applies to any confusing appearance
of the external genitalia. This includes any infant with
1 A phallus but bilaterally unpalpable testes
2 Unilateral cryptorchidism and hypospadias
3 Penoscrotal or perineoscrotal hypospadias , even if the
testes are descended
Normal full-term male infant – Phallus at least 2.5 cm long
Normal full-term female infant – Clitoris less than 1cm ,
No posterior labial fusion
3. Normal sexual differentiation
Female phenotype development
• It requires 46,XX ch complement, WNT-4 signaling molecule, DAX-1 genetic factor.
• It is independent of fetal gonads
• Ovaries are formed by 13-16 wks of gestation
• Mullerian ducts – fallopian tubes, uterus and upper portion of vagina
• Urogenital tubercle, swelling and folds – clitoris, labia majora and labia minora.
Male phenotype development-
• It requires 46,XY ch complement, SRY gene, SOX-9, SF-1 and WT1 genatic factors
• 6-7 wks – AMH production by sertoli cells
• 8 wks – Testosterone by Leydig Cells
• 8-12 wks – hCG by placenta
• > 12 wks – LH by pituitary
• Virilization of wolffian duct –epididymis, vas, seminal vesical
• DHT – penis and scrotum
4. Etiological classification of intersex conditions
46,XX-Intersex ( 46,XX-Virilized )
Androgen Exposure.
Fetal source
21- Hydroxylase deficiency
11β- Hydroxylase deficiency
3β-HSD װ deficiency
Aromatase deficiency
Glucocorticoid receptor gene mutation
Maternal source
Virilizing ovarian tumor
Virilizing adrenal tumor
Androgenic drugs
46,XY-Intersex ( 46,XY-Undervirilized )
Defects in testicular differentiation
Denys-Drash syndrome
WAGR syndrome
Camptomelic syndrome
XY pure gonadal dysgenesis
Mutation in SRY gene
XY gonadal agenesis
Deficiency of testicular hormones
Leydig cell aplasia
Mutation in LH receptor
Lipoid adrenal hyperplasia
3β-HSD װ deficiency
17- Hydroxylase deficiency
Persistent mullerian duct syndrome
Antimullerian hormone
Receptor defects for anti-mullerian hormone
Defects in Androgen action
5α-Reductase װ mutations
Androgen receptor defects
Complete AIS
Partial AIS
Smith-Lemli-Opitz syndrome
Defect in conversion of 7-
dehydrocholesterol to cholesterol
True Gonadal Intersex
X X
XY
XX / XY chimeras
6. 46,XX Intersex ( 46,XX with virilization )
( female pseudohermaphroditism )
Genotype is XX, gonads are ovaries but external genitalia are virilized
Uterus, tubes and ovaries are developed
Clitoral hypertrophy and labioscrotal fusion
a) Congenital adrenal hyperplasia
- 21-hydrxylase, 11-hydrxylase, type װ3 β-HSD
- Salt looser have more virilization than non salt loosers
b) Aromatase deficiency
- Hypergonadotropic hypogonadism
- Enlargement of clitoris and posterior labial fusion
- Large ovarian cysts
- Low estrogen,high serum andrgens, high GnRH
7. c) Glucocorticoid receptor gene mutation-
- Autosomal dominant
- Elevated cortisol level
- Homozygus mutation in exons 5 of receptor
d) Virilizing maternal tumors –
- Adrenal adenoma, androblastoma, luteomas, krukenberg tumor
- Mother will manifest enlargement of clitoris, acne, deepening of
voice, decreased laction, hirsutism
- Elevated levels of testosterone, DHEA, androstenedione
- Infant will show enlargement of clitoris and labial fusion
e) Androgenic drugs-
- Testosterone, 17 methyl testosterone, progesterone
46,XX Intersex ( 46,XX with virilization )
( female pseudohermaphroditism )
8. 46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism )
Genotype is male, but external genitalia are ambiguous or completely female
Defects in testicular differentiation –
Deletion in short arm of Y chromosome , male differentiation
does not occur..Phenotype is female. Mullerian ducts are well
developed. Azoospermia and short stature.
(a) Denys –Drash syndrome –
- Focal and diffuse mesengial sclerosis
- Male pseudohermaphroditism
- Bilateral wilms tumor
(b) WAGR syndrome –
- Wilms tumor
- Aniridia
- Genitourinary malformations
- Retardation
9. (c) Camtomelic syndrome –
- Short limb dysplasia, anterior bowing of tibia and fibula.
- External internal genitalia are female.
- Gene responsible is SOX-9.
- It regulates the type 2 collagen gene development.
(d) XY Pure gonadal dysgenesis (SWYER syndrome) –
- X-linked recessive, mutation in SYR gene
- Normal stature
- Female phenotype
- Vagina, uterus ,fallopian tubes are present
- Gonads consist of undifferentiated streaks
- Breast development and menarche fail to occur at puberty
(e) XY Pure gonadal agenesis –
- External genitalia female
- No uterus vagina and gonadal tissue found
- Hypoplasia of labia, labioscrotal fusion, perianal urethra
- No sexual development occur at puberty
46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism )
10. Defects in testicular hormones –
a) Leydig cell aplasia
- Autosomal dominant
- Phenotype female
- Testes, vas, epididymis are present
- Uterus and fallopian tubes are absent
- No secondary sexual characteristics at puberty
- Testosterone decreased, no hCG response, increased LH, low FSH
b) Lipoid adrenal hyperplasia
- Mutation in StAR
- Enlarged adrenal gland due to accumulation of chlosterol and cholesteraol
esters
- All steroids are low where as corticotropin and plasma renin level are high
- Phenotype is female in genetic male and female
- Genetic males produce AMH but no steroids
- Present in infancy as acute adrenal crisis with salt wasting
46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism )
11. 46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism )
c) 3β HSD deficiency –
- Point mutation in type װ3 β HSD in gonads and adrena0ls
- Hypospadias with or without bifid scrotum and cryptorchidism
- Salt loosing manifestations shortly after birth
- Normal pubertal development in some patients due to type 1 3β HSD in
peripheral tissue
d) 17 hydroxylase & 17,20 lyase deficiency –
- Genetic males usually present with undervirilization from labioscrotal fusion
to perineal hypospadias and cryptorchidism
- DOC level is increased leading to hypokalemia and hypertension
- Renin- aldosterone axis is suppressed
- Cortisol levels are low, corticotropin and corticosterone are high
- Virilization does not occur at puberty
12. 46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism
e) 17 ketosteroid reductase deficiency –
- Autosomal recessive
- 46 xy males with complete femal phenotype
- Mullerian ducts are absent
- Diagnosed at puberty due to failure to menstruate and
virilization
f) Persistent mullerian duct syndrome –
- Cryptorchidism in 80% cases
- Testicular functions are normal
- Low AMH level
- Some patients may acquire testicular tumor
13. 46,XY Intersex (46,XY with undervirilization )
( Male pseudohermaphroditism
Defects in androgen action –
a) 5α Reductase deficiency
- Autosomal recessive
- Biosynthesis and peripheral conversion actions of testosterone are normal
- Small phallus,bifid scrotum, urogenital sinus with perineal hypospadias and
blind vaginal pouch
- Growth of facial hair and of prostate are DHT dependent
- Normal testosterone level, low DHT, testosterone : DHT >17
- High ratio of urinary etiocholanolone to androsterone and 5β to 5 α
metabolites
b) Androgen insensitivity syndrome –
- X-linked recessive, normal 46 XY chromosome
- Testicular tissue and testosterone are normal
- Genetic males appear female at birth
- At puberty, normal development of breast, habitus is female but
menstruation does not occur
- Normal levels of testosterone and DHT, high gonadotropin level
- Azoospermia and infertility are common
14. True hermaphroditism
• Both ovarian and testicular tissue present either in the same or in
the opposite gonads
• Kayotypes – 46,XX ( 70% );
– 46,XY ( 10% );
– 46,XX / 46,XY ( 20% ).
• Most frequent gonads are bilateral ovotestes
• Ovarian tissue is normal but testicular tissue is dysgenetic
• Patient who are highly virilized, have good testicular function, and
have no uterus are usually reared as males
• If uterus exists, virilization mild, testicular function minimal, reared
as females
• 5α reductase deficiency – reared as males
• Androgen receptor defect – reared as females
• 46,XX / 46,XY – reared as females
• XY males with receptor defect and micropenis are treated by three
monthly IM injections 25-50 mg of testosterone enanthate.
15. Clinical approach to the diagnosis of ambiguous
genitalia
Family history –
- Testicular feminization – X-linked recessive
- CAH – Autosomal recessive
- Gestational history – H/O testosterone and progesterone
Growth failure –
- Girls with Turner – short
- Boys with klenifelter – Tall
- CAH – short
Gonads –
- Palpable gonad at inguinal ring is always testes
- Ovary seldom herniats at inguinal ring
- Rectal examination – useful for evaluation of vaginal pouch,
uterus or prostate
Imaging techniques –
- Bone age advanced – CAH
- Bone age delayed – gonadal dysgenesis, hypopituitarism
- Retrograde genitourethrogram – urogenital sinus
- Pelvic USG,CT, MRI – Internal genitalia, undescended gonads, adrenal anomaly
16. Clinical approach to the dignosis of ambiguous
genitalia
Peripheral blood karyotype –
a) If sex chromatin is positive or karyotype is 46,XX the patient may be true
hermaphrodite or female pseudohermaphrodite
b) If sex chromatin is negative or karyotype is 46,XY the patient may be male
pseudohermaphrodite and true hermaphrodite is rare
Hormonal investigations –
- Basal testosterone, estrogen and gonadotropin levels
- Testosterone / DHT ratio
- 24 hr urinary 17 ketosteroids and pregnanetriol
- Adrenal steroids – 17-OHP , DHEA, cortisol