Abnormal sexual Development Flashcards
What week of gestation do testes differentiate?
6th week gestation
What is the default sex?
female
What must be present for gonads to become testes?
Testes Determining Factor (TDF)
SRY
Where is SRY located, in what genetic region?
Located on the short arm of the Y chromosome in the SRY region
The wollfian ducts are also known as the _____ and represent the ______ (male /female) structures.
Mesonephric ducts, male.
The Mullerian ducts are also known as the ____ and represent the _____(male/female) structures.
Paramesonephric ducts, female
What contributes to the regression of the wolffian ducts?
absence of SRY, presence of estrogen
Anti-Mullerian Hormone (AMH) is produced by what cells?
Sertoli Leydig cells
AMH is responsible for what in terms of sexual differentiation?
Regression of mullerian ducts, abdominal descent of testes
When do the sertoli Leydig cells begin to produce testosterone during embryological development?
8 weeks gestation
What does testosterone stimulate during sexual differentiation?
Stimulates descent of testes into inguinal canal, differentiation of Wolffian ducts
What do the wolffian ducts turn into?
Epididymis, vas deferens, seminal vesicles
What do the mullerian ducts turn into?
Uterus, Fallopian tubes, upper vagina
at what weeks gestation does external masculinization occur?
Week 9 - 14
What are the three embryologic structures that will become the external genitalia?
Genital tubercle, urogenital sinus, labioscrotal swelling
Testosterone must be converted to _____ by the enzyme_____ in order for masculine external genitalia to develop.
Dihydrotestosterone (DHT), 5 alpha reductase
By what week gestation is female external genitalia developed?
20 weeks
The Genital Tubercle turns into the _____ in the presence of DHT
Penis
The Genital Tubercle turns into the ____ without presence of DHT
Clitoris
The Urogenital Sinus turns into the ____ in the presence of DHT
Urethra
The Urogenital Sinus turns into the ______ in the absence of DHT
Urethra, vagina, labia minora
The labialscrotal swellings turn into the ____ in the absence of DHT
Labia Majora
What three syndromes can cause 46 XX but male phenotype?
CAH, High maternal androgen state, Aromatase deficiency
What is the most common cause of ambiguous genitalia?
Congenital Adrenal Hyperplasia
What two types of ovarian tumors can cause high maternal androgen production during pregnancy?
Pregnancy Luteoma, Theca Lutein Cysts
Do Theca lutein cysts cause fetal virilization?
No
Do Pregnancy luteomas cause fetal virilization?
Yes
For patients with Androgen Insensitivity syndrome, What is there Karyotype and what is their phenotypic external genitalia?
46 XY, Female
Do patients with Androgen Insensitivity have a uterus?
No
When should testes be removed in a patient with androgen insensitivity syndrome?
After completion of puberty
What is the genetic inheritance pattern for Androgen Insensitivity?
X linked Recessive
What is the genetic inheritance pattern for 5 alpha reductase deficiency?
Autosomal Recessive
True or false: in a patient with 5 alpha reductase deficiency, starting at puberty masculinization can occur?
True
When should the testes be removed in a patient with Swyer syndrome?
As soon as possible
What is the most common gonadal tumor to occur in individuals with 46 XY karyotype and female phenotype?
Gonadoblastoma
What is the most common karyotype of true hermaphrodites?
46 XX
In a baby born with ambiguous genitalia, what should be ruled out first?
CAH
What tests should be ordered to rule out CAH?
17 - OHP, 11- deoxycorticosterone, 11-deoxycortisol
What will ordering a FISH accomplish in the workup of ambiguous genitalia?
Presence of SRY
