Paeds Endocrine Flashcards
What level HbA1c are you aiming for in good control of diabetes in children?
<7.5%
What can cause disorders of the hypothalamic pituitary axis?
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
What are the signs of GH defieciency?
Short stature , reduced height velocity, increased adiposity, mid facial hypoplasia, frontal bossing.
What are the signs of TSH defieciency?
Short and fat, dry skin, Bradycardia, oedema, hypothermia, increased reflex relaxation time.
Can lead to severe learning difficulties
What are the signs of LH and FSH deficiency?
Neonatal- micro penis, undescended testis, underdeveloped scrotum.
Child- Failure to progress into puberty.
What are the signs of vasopressin deficiency?
Dehydration, polyuria, polydipsia
What is the endocrine physiology for growth?
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
Which gene causes short stature and is associated with turners syndrome?
SHOX gene
What is silver-Russell syndrome?
Type of primordial dwarfism. Thought to be caused by hypomethylation of h19-igf2 region on chrom 11p.15
What disease may be suspected by looking at a growth chart before and after weaning?
Coeliac disease- FTT during/after weaning
What mutation leads to Marfans syndrome?
Fbn1 on chromosome 15. Fibrillin-1 used in biogenesis and elastic fibres.
What is beckwith- wiedemann syndrome?
Overgrowth disorder
Chromosome 11, 11p15. Overactivity of IGF-2 gene (growth factor) and no activity if cdkn1c (inhibits cell proliferation)
What are the first signs of puberty in boys and girls?
Boys- increase testical volume
Girl - breast development
What age in boys and girls defines precocious puberty?
Girls <8, menarche <10
Boys <9
Treatment GnRH analogues (stops pulsatile signalling)
In males, what hormone is responsible to stop the growth of a uterus?
Sertoli cells-> anti-mullerian hormone (AMH) which suppresses female structures
What is the most common cause of disorders of sexual development?
Congenital andrenal hyperplasia
Ambiguous genitalia
When does TSH, FT4 and FT3 enter the normal range in neonatal life?
TSH - by day 5
FT3 and ft4 - by day 14
What is Pendred syndrome?
Congenital deafness and goitre/hypothyroidism
AR- PDS gene which codes for pendrin (SLC26A4)
What are the signs of neonatal thyroxicosis?
Growth retardation, goitre (may compress trachea), jittery, tachycardia, hypertension, hypermetabolic (Hungry, wt loss, sweating, diarrhoea)
Which is the most common enzyme affected in CAH (congenital adrenal hyperplasia)?
21- hydroxylase deficiency (cyp21a2)
Leading to high amounts of 17a-hydroxyprogesterone (this is what causes salt-wasting)
What are the signs of CAH? In males/ females
Females - ambiguous genitalia, growth acceleration
Males- salt wasting -> hyponatimia/ hypovolemia. Later: virillization
How do you investigate CAH?
Synachten test with 17OHP, USP Electrolytes Bone age Genetics
What is the treatment for CAH (21OH def)?
- Hydrocortisone (reduces hyperplasia and overproduction of androgens and mineralocorticiods)
- Fludrocortisone and initially NaCl supplementation
How does acute adrenal insufficiency present?
Shock, apathy, nausea, vomiting, abdominal pain, hypoglycaemia.
Rx - hydrocortisone
What are the main causes of cushings in children?
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)
How does phenylketonuria present if missed in the heel prick?
High phenylalanine leads to learning difficulties/ development delay and seizures
Often blonde hair and blue eyes
Eczema
Musty odour to urine and sweat
