Sexual Differentiation And Their Disorders Flashcards
What is the gene that gives instructions for the undifferentiated gonads to become a testis?
SRY gene on chromosome Y
What is the region on the Y chromosome where crossing over occurs with chromosome X during meiosis?
Pseudoautosomal region
When does differentiation of sexual organs begin? And completed?
At 6 months and completed by 8-12 w Intrauterine
What are the cells that secrete mullerian inhibitory factor in the testis
Sertoli cells
What are the cells secreting testosyerone in the testis causing wolfian development?
Leidig cells
In steroidogenesis, what is the enzyme needed for production of cortisol?
11 beta hydroxylase
In steroidogenesis, what is the enzyme responsibile for converting testosterone into DHEA?
5alpha reductase
In steroidogenesis, what is the enzyme used for convertion of deoxycorticosterone into corticoaterone?
11beta haydroxylase
In steroidogenesis, what is the enzyme used for convertion of androstenedione to testosterone?
17 beta hydroxydehydrogenase
What is the type of hypogonadism in turner syndrome?
Hypergonadotrophic Hypogonadism (↑LH,↑FSH,↓estradiol)
What is the karyotype of mixed gonadal dysgeneis?
(45XO, 46XY mosaicism)
Karyotype of kleinfelter syndrome
47 xxy
A 25 day old baby with salt losing manifestations (Addisonian
crisis). There are 2 normally sized testes present in a bifid scrotum,
micropenis and a penoscrotal hypospadius. There is also bilateral
hydrocele. Low levels of Androstendione and testosterone but high
levels of dehydroepiandrostenedione. Absent mullerian structures
What is the diagnosis?
Disorders of sexual Differentiation and congenital adrenal hyperplasia due to defect in 3 beta hydrosteroid dehydrogenase enzyme
Most common cause of congenital adrenal hyperplasia
21 hydroxylase deficiency
