male gonadal issues

Question 1

give possible causes of hypogonadotrophic hypogonadism

Answer 1

Have a situation of hypopituitarism with causes including:
• Pituitary tumour
o May be exerting a pressure effect on the cells or be a tumour secreting prolactin – high levels of prolactin will suppress LH and FSH
 Suppress normal activity of the testicles
• Pituitary surgery or radiotherapy
• Head injury – shear forces can shear the pituitary (rare)
• Genetic syndromes e.g.polydactyly
• Cerebellar ataxia
o Can have a combined disorder of the two
• Kallmann’s syndrome - Most common cause

Question 2

describe Kallmann’s syndrome

Answer 2

failure of cell migration of GnRH cells to the hypothalamus from the olfactory placode
It is associated with aplasia/hypoplasia of the olfactory lobes so often people have anosmia.
Familial pattern of inheritance but has incomplete penetrance.

Question 3

describe the presentation of Kallmann’s syndrome

Answer 3

childhood - poor growth and undescended testes.
Adolescence - poor growth, small testes, micropenis, delayed or absent puberty
Adulthood - slow but eventually adequate growth, small testes, short phallus, hypogonadal features

Question 4

what is the most common cause of hypoonadotrophic hypogonadism

Answer 4

Kallmann’s syndrome

Question 5

give some causes of primary gonadal disease

Answer 5

Kllinefelter’s Syndrome - Chromosomal defect
• Seminiferous tubule failure
• Adult Leydig cell failure
• Cryptorchidism
• Complex genetic disorders - E.g. myotonic dystrophy

Question 6

how are hypogonadal issues treated

Answer 6

Androgen replacement ± psychological support ± fertility counselling

Question 7

name some side effects of androgen replacement

Answer 7

mood issues - aggression and other behavioural changes, libido issues (can be too high for their partner), increased haematocrit, possible effects of prostate, acne, sweating, gynaecomastia

Question 8

what is the genetic abnormality in Klinefelter’s syndrome

Answer 8

XXY (others can exist)

Question 9

when will Klinefelter’s become obvious?

Answer 9

puberty as they will fail to develop secondary characteristics

Question 10

what are thegonadotrophins like in Klinefelter’s syndrome and why?

Answer 10

LH and FHS are increased as they are trying to stimulate the seminiferous tubules and leydig cells but the tubules regress and Leydig cells do not function normally.

Question 11

which gene is associated with Kallmann’s syndrome

Answer 11

KAL