3. Paeds [Endocrine, Diabetes & Growth]

Question 1

Give 5 clinical features of Turner Syndrome.

Answer 1

Short stature (may be the only clinical abnormality)

Primary amenorrhoea

Webbed neck

Wide spaced nipples

Bicuspid aortic valve / coarctation of the aorta

Question 2

What syndrome is denoted by 45,XO or 45,X

Answer 2

Turner Syndrome

Question 3

Define precocious puberty.

Answer 3

Developmental of secondary sex characteristics before the age of 8 years in females and 9 years in males.

Question 4

What 2 categories can precocious puberty be classified as?

Answer 4

Gonadotrophin dependent (‘central’)

Gonadotrophin independent (‘pseudo’)

Question 5

What is the physiological cause of ‘central’ precocious puberty, and what would the FSH and LH test show?

Answer 5

Gonadotrophin dependent; due to premature activation of the HPG axis.

FSH and LH raised.

Question 6

What is the physiological cause of ‘pseudo’ precocious puberty?

Answer 6

Gonadotrophin independent; due to excess sex hormones.

FSH and LH low.

Question 7

In males presenting with precocious puberty, there is usually an organic cause as it is much more uncommon than females. Give 3 different presentations of testes and what they might mean in terms of an organic cause.

Answer 7

Bilateral enlarged: gonadotrophin release from intracranial lesion

Unilateral enlarged: gonadal tumour

Small testes: adrenal cause (tumour or adrenal hyperplasia)

Question 8

Define delayed puberty.

Answer 8

Absence of pubertal development / secondary sex characteristics by the age of 13 in girls and 14 in boys.

Question 9

Give 3 causes of delayed puberty.

Answer 9

Constitutional / familial delay of growth and puberty

Low gonadotrophin secretion (hypogonadotrophic hypogonadism)

High gonadotrophin secretion (hypergonadotrophic hypogonadism)

‘Constitutional’ is by far the most common in boys. As the ovaries are sensitive to gonadotrophins, delayed puberty in girls should be investigated.

Question 10

Give 2 chromosomal abnormalitied and 2 examples of acquired gonadal damage that can result in hypergonadotrophic hypogonadism.

Answer 10

Turner’s (45,XO) and Klinefelter’s (47,XXY)

Surgery / chemo / radiotherapy etc

Question 11

Causes of hypogonadotrophic hypogonadism can be split into systemic and hypothalamic-pituitary disorders. Give 3 systemic and 3 HP disorders that can cause this.

Answer 11

Systemic; excess physical training, CF, severe asthma, Crohn’s, anorexia / starvation

HP; pituitary dysfunction, intracranial tumours, Kallmann syndrome (LH deficiency + anosmia), isolated Gntrophin or GH deficiency

Question 12

As delayed puberty in girls is more uncommon, it should be investigated. Outline 3 investigations that should be undertaken.

Answer 12

MRI to rule out pituitary pathology
Karyotyping for Turner’s and Klinefelter’s
Hormone levels (GH, LH, FSH,)

Also consider eating disorder

Question 13

In what condition does 90% of the patient group have a 21-hydroxylase enzyme deficiency, and what is this enzyme needed for?

Answer 13

Congenital Adrenal Hyperplasia

21-hydroxylase is needed for cortisol biosynthesis

Question 14

CAH is the most common cause of non-iatrogenic cortisol and mineralocorticoid deficiency. Describe the effects of the lack of these hormones physiologically.

Answer 14

Cortisol; lack of cortisol stimulates the pituitary to produce more ACTH, which drives overproduction of adrenal androgens

Aldosterone; salt loss with low Na+ and high K+ (in some cases)

Question 15

Long term management of CAH (3 points):

Answer 15

Lifelong glucocorticoids e.g. hydrocortisone to suppress ACTH levels, and therefore testosterone, to allow normal growth and maturation

If there is salt loss, fludrocortisone may also be prescribed

Additional hormone replacement in illness or surgery, as unable to amount a cortisol response

Question 16

5 clinical features of CAH:

Answer 16

Virilisation (ambiguous genitalia in females etc)
Salt-wasting crisis
Precocious puberty
Infertility
Height and growth abnormalities

Question 17

In salt-losers with CAH, what are the biochemical abnormalities?

Answer 17

Low sodium
High potassium
Metabolic acidosis
Hypoglycaemia

Question 18

Cushing syndrome in children is very rarely non-iatrogenic. What are 3 conditions that may require prolonged courses of steroids that could cause this syndrome in children?

Answer 18

Nephrotic syndrome
Asthma
ALL

Question 19

3 tools imperative to assessing a child with short stature.

Answer 19

History
Examination
Growth charts

Question 20

Give 3 endocrine causes of short stature.

Answer 20

Hypothyroidism

Steroid excess (iatrogenic causing Cushing syndrome) (*very rarely non-iatrogenic in children)

GH deficiency / IGF-1 deficiency

*These are associated with children being overweight relative to their height, unlike nutritional obesity where children are usually relatively tall compared to their mid-parent centile.

Question 21

What condition is caused by a mutation in FGFR-3 and is inherited in an AD pattern?

Answer 21

Achondroplasia

Sporadic mutation in 70% and then passed on in AD fashion after that.

Question 22

5 clinical features of achondroplasia

Answer 22

Rhizomelia (short limbs)
Brachydacytly (shortened fingers)
Frontal bossing and large head
Midface hypoplasia with flattened nasal bridge
Lumbar lordosis

Question 23

What is the main risk factor for achondroplasia?

Answer 23

Advancing parental age

Question 24

Outline some standard investigations for short stature when a child is below the 0.4th centile

Answer 24

FBC (anaemia indicating nutritional deficiency, Crohn’s, coeliac)

TSH; hypothyroidism

Karyotyping in all girls (Turner’s)

XR left hand and wrist; skeletal maturity mild (constitutional delay) vs marked (hypothyroid, GH def. )

Creatinine, LFTs, electrolytes; renal or hepatic dysfunction

Anti-TTG with paired IgA; coeliac

IGF-1 (GH deficiency)