3. Paeds [Endocrine, Diabetes & Growth] Flashcards
Give 5 clinical features of Turner Syndrome.
Short stature (may be the only clinical abnormality)
Primary amenorrhoea
Webbed neck
Wide spaced nipples
Bicuspid aortic valve / coarctation of the aorta
What syndrome is denoted by 45,XO or 45,X
Turner Syndrome
Define precocious puberty.
Developmental of secondary sex characteristics before the age of 8 years in females and 9 years in males.
What 2 categories can precocious puberty be classified as?
Gonadotrophin dependent (‘central’)
Gonadotrophin independent (‘pseudo’)
What is the physiological cause of ‘central’ precocious puberty, and what would the FSH and LH test show?
Gonadotrophin dependent; due to premature activation of the HPG axis.
FSH and LH raised.
What is the physiological cause of ‘pseudo’ precocious puberty?
Gonadotrophin independent; due to excess sex hormones.
FSH and LH low.
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.
Bilateral enlarged: gonadotrophin release from intracranial lesion
Unilateral enlarged: gonadal tumour
Small testes: adrenal cause (tumour or adrenal hyperplasia)
Define delayed puberty.
Absence of pubertal development / secondary sex characteristics by the age of 13 in girls and 14 in boys.
Give 3 causes of delayed puberty.
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.
Give 2 chromosomal abnormalitied and 2 examples of acquired gonadal damage that can result in hypergonadotrophic hypogonadism.
Turner’s (45,XO) and Klinefelter’s (47,XXY)
Surgery / chemo / radiotherapy etc
Causes of hypogonadotrophic hypogonadism can be split into systemic and hypothalamic-pituitary disorders. Give 3 systemic and 3 HP disorders that can cause this.
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
As delayed puberty in girls is more uncommon, it should be investigated. Outline 3 investigations that should be undertaken.
MRI to rule out pituitary pathology
Karyotyping for Turner’s and Klinefelter’s
Hormone levels (GH, LH, FSH,)
Also consider eating disorder
In what condition does 90% of the patient group have a 21-hydroxylase enzyme deficiency, and what is this enzyme needed for?
Congenital Adrenal Hyperplasia
21-hydroxylase is needed for cortisol biosynthesis
CAH is the most common cause of non-iatrogenic cortisol and mineralocorticoid deficiency. Describe the effects of the lack of these hormones physiologically.
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)
Long term management of CAH (3 points):
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
5 clinical features of CAH:
Virilisation (ambiguous genitalia in females etc)
Salt-wasting crisis
Precocious puberty
Infertility
Height and growth abnormalities
In salt-losers with CAH, what are the biochemical abnormalities?
Low sodium
High potassium
Metabolic acidosis
Hypoglycaemia
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?
Nephrotic syndrome
Asthma
ALL
3 tools imperative to assessing a child with short stature.
History
Examination
Growth charts
Give 3 endocrine causes of short stature.
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.
What condition is caused by a mutation in FGFR-3 and is inherited in an AD pattern?
Achondroplasia
Sporadic mutation in 70% and then passed on in AD fashion after that.
5 clinical features of achondroplasia
Rhizomelia (short limbs)
Brachydacytly (shortened fingers)
Frontal bossing and large head
Midface hypoplasia with flattened nasal bridge
Lumbar lordosis
What is the main risk factor for achondroplasia?
Advancing parental age
Outline some standard investigations for short stature when a child is below the 0.4th centile
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)
