Endocrine/Reproductive - Gonadotropin Deficiency + Kellamann

Question 1

Defintion

Answer 1

Lack of sex hormones, oestrogen, and testosterone
Causes delay in puberty

Question 2

Causes

Answer 2

• Hypogonadotrophic hypogonadism: adeficiency of LH and FSH
• Hypergonadotrophic hypogonadism: a lack of response to LH and FSH by the gonads

Question 3

Hypogonadotrphic hypogonadism definition

Answer 3

Deficiency of LH and FSH → no stimulation to gonads → cannot produce testosterone or oestrogen

Question 4

Causes of hypogonadotropic hypogonadism

Answer 4

• radiotherapy or cancer
• growth hormone deficiency
• hypothyroidism
• hyperprolactinaemia
• IBD, CF
• excessive exercise
• kallman

Question 5

Hypergonaotropic hypogonadism defintion

Answer 5

• glands fail to respond to stimulation from gonadotrophins (LH and FSH)
• no negative feedback from sex hormones → anterior pituitary produces increasing amounts of LH and FSH → high FHS,LH levels but low sex hormones levels

Question 6

Causes of hypergonadotropic hypogonadism

Answer 6

• testicular torsion, cancer, infection
• Congenital absence of the testes or ovaries
• Kleinfelter’s Syndrome (XXY)
• Turner’s Syndrome (XO)

Question 7

KELLMANN

Answer 7

• Delayed puberty secondary to hypogonadotrophic hypogonadism
• X-linked recessive trait

Question 8

Aetiology

Answer 8

Caused by failure of GnRH-secreting neurons to migrate to the hypothalamus.

Question 9

Features

Answer 9

• ‘delayed puberty’
• hypogonadism, cryptorchidism
  anosmia
• sex hormone levels are low
• LH, FSH levels are inappropriately low/normal
  patients are typically of normal or above-average height
• Cleft lip/palate and visual/hearing defects are also seen in some patients

Question 10

Diagnosis

Answer 10

• threshold → no pubertal changes in girls >13 and boys >14
• FBC and ferritin → anaemia
• U&E for CKD
• anti-TTG and anti EMA → coeliac
• early morning FSH and LH serum (low in hypo and high in hyper)
• TFT
• GH testing
• serum prolactin
• genetic testing → Kleinfelter and Turner
• imaging → XRAY wrist (delay), pelvic USS, MRI of brain (olfactory bulbs in Kallman syndrome

Question 11

Treatment

Answer 11

• Treat underlying condition
• Replace sex hormones - gonadotrophin supplementation may result in sperm production if fertility is desired later in life