Disorders of sexual development Flashcards
Primary hypogonadism:
Klinefelter’s
LH: High
Testosterone: Low
Hypogondaotrophic hypogonadism:
Kallman’s syndrome
LH: Low
Testosterone: High
Androgen insensitivity syndrome:
LH: High
Testosterone: Normal/high
Testosterone-secreting tumour:
LH: Low
Testosterone: High
Karyotype of Klinefelter’s:
47, XXY
Features of Klinefelter’s:
Tall Lack of secondary sexual characteristics Small, firm testes Infertile Gynaecomastia Elevated gonadotrophin levels
What is Kallman’s syndrome?
Cause of delayed puberty secondary to hypogonadtrophic hypogonadism
Failure of GnRH releasing neurones to migrate to the hypothalamus
Usually inherited as an X-linked recessive trait
Key differential feature of Kallman’s?
Anosmia (inability to smell)
Features of Kallman’s:
Anosmia (inability to smell) Delayed puberty Hypogonadism, cryptorchidism Sex hormones, LH and FSH are inappropriately low (FSH and LH can be inappropriately normal) Normal or above average height
Associated signs of Kallman’s in some patients?
Cleft lip and palate
Visual/hearing defects
What is androgen insensitivity syndrome?
End-organ resistance to testosterone makes genotypical male children (46, XY) appear phenotypically female
Features of androgen insensitivity syndrome:
Primary amenorrhoea
Undescended testes causing groin swellings
Breast development may occur due to the conversion of testosterone to oestradiol
Management of androgen insensitivity syndrome:
Counselling
Bilateral orchidectomy - raised chance of testicular cancer with undescended testes
Oestrogen therapy
First pubertal development in males?
Testicular growth at around 12 years of age
Volume >4ml indicates onset of puberty
When is the height spurt in males and females?
Males: 14 years
Females: 12 years
