Endocrinology Flashcards
What are the known genes that can cause precocious puberty?
MKRN3, KISS1R, KISSPEPTIN, DLK1
What can you treat precocious puberty with?
GnRH agonist
What cancer are boys with Klinfelters more predisposed to?
Breast cancer
What medication can be used in boys with gynaecomastia?
Aromatase inhibitors
Tamoxifen
Blocks oestrogen which then doesn’t have negative feedback to hypothalamus which results in increased production of LH and FSH = increased androgen
What happens to the calcium, PTH and phosphate in hypoparathyroidism?
Low calcium, high/normal phosphate and low/normal PTH
Treatment of hypoparathyroidism?
Oral calcium supplements
IV infusion is severe
Calcitriol (1,25 dihydroxy vitamin D) - PTH activates vitamin D therefore can’t given inactive replacement
Short stature, obesity
Shortened 3rd ‐5th metacarpals
Syndactyly between 2nd and 3rd toes
Round face , flat nasal bridge, short neck
Subcutaneous calcifications
Cataracts
Pseudohypoparathyroidism
Albright’s hereditary osteodystrophy
What is Burosumab?
Human monoclonal antibody against FGF23 used in X-linked hypophosphatemic rickets. It increases tubular reabsorption of phosphate.
What is the action of bisphosphonates and what are they used for?
Inhibit calcium release by interfering with the
metabolic activity of osteoclasts/cytotoxic to
osteoclasts.
Used to treat hypercalcaemia
What is tolvaptin and what is it used for?
Selective V2 receptor antagonist used in severe refractory SIADH.
Binds to vasopressin receptor stopping activation.
What is the triphasic response following a craniopharyngioma surgical resection?
Acute phase - patient presents with hypernatraemia due to DI
Interphase phase - patient then goes into SIADH
Permanent phase - patient then goes back to DI
What are the clinical features of cerebral salt wasting?
Hyponatraemic
Polyuria with high urine sodium
Usually clinically dehydrated
What is central pontine myelinolysis?
Central pontine myelinolysis (CPM), also known as osmotic demyelination syndrome, is a neurological disorder that most frequently occurs after too rapid medical correction of sodium deficiency (hyponatremia). The rapid rise in sodium concentration also involves the movement of small molecules and pulls water from brain cells that leads to the destruction of myelin, a substance that surrounds and protects nerve fibers. Nerve cells (neurons) also can be damaged.
What can be used to treat nephrogenic DI?
Indomethocin -Inhibitor of PgE2 synthesis.
proximal tubular Na reabsorption due to
increased medullary tonicity
Hydrochlorothiazide -Body Na depletion leads to increases fractional fluid resorption in proximal tubule.
What is the genetic mutation associated with Pendred syndrome?
SLC26A4
