Week 5 - F - Male hypogonadism

Question 1

In male hypogonadism Just like in females There is primary and secondary hypogonadism What is the difference in the measurements when testing for primary/ secondary hypogonadism in men?

Answer 1

Primary - low testosterone with a high LH/FSH

Secondary - Low testosterone with a low LH/FSH

In females it is just oestrogen that is measured instead of testosterone

Question 2

Name 3 congenital causes of primary hypogonadism in males?

Answer 2

Klinefelter syndrome

Y-chromosome micro-deletions

LH and FSH receptor mutations

Question 3

Name an acquired cause of primary hypogonadism in males?

Answer 3

Testicular trauma or torsion

Testicular radiation

Question 4

Name 2 secondary hypogonadism causes in males? (arises in hypothalamus or pituitary)

Answer 4

Idiopathic hypogonadotrophic hypogonadism - Kallman’s syndrome

Hyperprolactinaemia

Question 5

What are the features of Kallman’s syndrome? (3 features) There are over 25 genes implicated in the disruption to the production/actvitiy of the GnRH (gonadotrophic releasing hormone) in Kallmans. Which is the most commonly affected gene?

Answer 5

Kallman’s syndrome is usually

* idiopathic hypogonadotrophic hypogonadism with anosmia

* and often colour blindness

ANOS1 gene defect on X-chromosome is the defect most commonly tested for

Question 6

What are the symptoms of male hypogonadism? What are the signs?

Answer 6

Sexual function (libido, erections, ejaculation)

Age of puberty, shaving frequency etc

Fertility

Symptoms of pituitary disease

Staging of puberty (secondary sexual characteristics)

Testicular volume

Question 7

What is this karyotype showing? Most common congenital form of primary hypogonadism in males

Answer 7

Klinefelter’ syndrome - 47 XXY

Question 8

What symptoms show klinefelters? (levels of testosterone, LH/FSH, SHBG and oestradiol)

Answer 8

Low testicular volume

Gynaecomastia

Remember it is a primary cause of hypogonadism - Low testosterone, high LH/FSH (elevated SHBG/oestradiol)

Question 9

What syndrome arising due to excessive hunger due to increased hormone grhelin can cause secondary hypogonadism? Increased grehlin causes decreased production of GnRH

Answer 9

Prader-Willi syndorme

Question 10

What is the deletion in Prader-Willi syndrome?

Answer 10

The deletion is usually when part of paternal chromsome 15 is deleted (most common)

Or when there are 2 maternal chromosome 15 as the paternal copy lacks

Question 11

In male hypogonadism, testosterone replacement therpay is an option Remember: Testosterone therapy will not restore fertility What can testosterone replacement do to spine and hip BMD?

Answer 11

Increases spine and hip BMD