Paeds Endocrine

Question 1

What level HbA1c are you aiming for in good control of diabetes in children?

Answer 1

<7.5%

Question 2

What can cause disorders of the hypothalamic pituitary axis?

Answer 2

Congenital - gene mutations e.g. Pou1f1, pitx1.

Central nervous system disorders -

• tumours e.g. Craniopharyngioma, germ cell tumours,
• langerhans cell histiocytes
• post infection e.g. Meningitis
• head trauma
• irradiation

Question 3

What are the signs of GH defieciency?

Answer 3

Short stature , reduced height velocity, increased adiposity, mid facial hypoplasia, frontal bossing.

Question 4

What are the signs of TSH defieciency?

Answer 4

Short and fat, dry skin, Bradycardia, oedema, hypothermia, increased reflex relaxation time.

Can lead to severe learning difficulties

Question 5

What are the signs of LH and FSH deficiency?

Answer 5

Neonatal- micro penis, undescended testis, underdeveloped scrotum.

Child- Failure to progress into puberty.

Question 6

What are the signs of vasopressin deficiency?

Answer 6

Dehydration, polyuria, polydipsia

Question 7

What is the endocrine physiology for growth?

Answer 7

Hypothalamus -> GHRH and somatostatin -> pulsatilla release of GH from pit (GH binding protein complex) -> liver and other organs -> igf1 production -> GH and igf1 act on the epiphyseal growth plate -> stimulates proliferation of chondrocytes -> bone

Question 8

Which gene causes short stature and is associated with turners syndrome?

Answer 8

SHOX gene

Question 9

What is silver-Russell syndrome?

Answer 9

Type of primordial dwarfism. Thought to be caused by hypomethylation of h19-igf2 region on chrom 11p.15

Question 10

What disease may be suspected by looking at a growth chart before and after weaning?

Answer 10

Coeliac disease- FTT during/after weaning

Question 11

What mutation leads to Marfans syndrome?

Answer 11

Fbn1 on chromosome 15. Fibrillin-1 used in biogenesis and elastic fibres.

Question 12

What is beckwith- wiedemann syndrome?

Answer 12

Overgrowth disorder

Chromosome 11, 11p15. Overactivity of IGF-2 gene (growth factor) and no activity if cdkn1c (inhibits cell proliferation)

Question 13

What are the first signs of puberty in boys and girls?

Answer 13

Boys- increase testical volume

Girl - breast development

Question 14

What age in boys and girls defines precocious puberty?

Answer 14

Girls <8, menarche <10
Boys <9

Treatment GnRH analogues (stops pulsatile signalling)

Question 15

In males, what hormone is responsible to stop the growth of a uterus?

Answer 15

Sertoli cells-> anti-mullerian hormone (AMH) which suppresses female structures

Question 16

What is the most common cause of disorders of sexual development?

Answer 16

Congenital andrenal hyperplasia

Ambiguous genitalia

Question 17

When does TSH, FT4 and FT3 enter the normal range in neonatal life?

Answer 17

TSH - by day 5

FT3 and ft4 - by day 14

Question 18

What is Pendred syndrome?

Answer 18

Congenital deafness and goitre/hypothyroidism

AR- PDS gene which codes for pendrin (SLC26A4)

Question 19

What are the signs of neonatal thyroxicosis?

Answer 19

Growth retardation, goitre (may compress trachea), jittery, tachycardia, hypertension, hypermetabolic (Hungry, wt loss, sweating, diarrhoea)

Question 20

Which is the most common enzyme affected in CAH (congenital adrenal hyperplasia)?

Answer 20

21- hydroxylase deficiency (cyp21a2)

Leading to high amounts of 17a-hydroxyprogesterone (this is what causes salt-wasting)

Question 21

What are the signs of CAH? In males/ females

Answer 21

Females - ambiguous genitalia, growth acceleration

Males- salt wasting -> hyponatimia/ hypovolemia. Later: virillization

Question 22

How do you investigate CAH?

Answer 22

Synachten test with 17OHP, 
USP
Electrolytes 
Bone age 
Genetics

Question 23

What is the treatment for CAH (21OH def)?

Answer 23

• Hydrocortisone (reduces hyperplasia and overproduction of androgens and mineralocorticiods)
• Fludrocortisone and initially NaCl supplementation

Question 24

How does acute adrenal insufficiency present?

Answer 24

Shock, apathy, nausea, vomiting, abdominal pain, hypoglycaemia.

Rx - hydrocortisone

Question 25

What are the main causes of cushings in children?

Answer 25

Steroid treatment
Pituitary (cushings - older children) e.g. ACTH producing microadenoma
Adrenal (younger children) e.g. Adrenal tumour, Mc Albright syndrome, PPNAD
Ectopic ACTH syndrome (rare)

Question 26

How does phenylketonuria present if missed in the heel prick?

Answer 26

High phenylalanine leads to learning difficulties/ development delay and seizures
Often blonde hair and blue eyes
Eczema
Musty odour to urine and sweat