Tubular disorders Flashcards
What is Fanconi syndrome?
Generalised impairment of proximal tubular function Leading to; - hypophosphatemia - glycosuria - hypouricaemia - aminoacidemia - LMW protein loss - Bicarbonate loss
Most common cause of Fanconi syndrome in kids?
Cystinosis
What is cystinosis?
lysosomal storage disorder (AR)
Abnormal accumulation of Amino acid cystine leads to renal injury
Type 1 RTA
Impaired distal acid secretion (leading to H retention)
- get stones
Type 2 RTA
Decreased proximal bicarb reabsorption
- no stones
Type 3 RTA
mixed
Type 4 RTA
hypoaldosteronism
Features of Gitelman’s syndrome
Onset during adolescence/young adulthood* hypokalaemia met alkalosis hypocalciuria hypomagnesaemia* elevated renin and aldosterone (DCT disorder) (*differentiated from Bartter's normal BP)
Features of Bartter’s syndrome
Onset during childhood* met alkalosis hypokalaemia hypocalciuria normal BP elevated renin and aldosterone magnesium wasting less common* (*differentiate from Gitelman's) (Loop Na/CL reabsorption disorder)
Features of Liddle’s syndrome
K wasting hypokalaemia alkalosis low renin and aldosterone hypertension
What is the pathological mechanism in Bartter’s syndrome
Impaired Loop Na/CL reabsorption which causes increased renin and aldosterone secretion
–> juxtaglomerular apparatus hyperplasia
Rcikets associated with proximal RTA (type II)
hypophosphataemic rickets (with low bicarb associated)
Rickets associated with distal RTA (type I)
vitamin D dependant rickets
Causes of type 1 RTA (distal)
GENETIC AD, AR forms Ehlers-Danlos syndrome Sickle cell anaemia ACQUIRED Medications: Amphoteracin B, Lithium Autoimmune: Sjogren syndrome, SLE Obstructive uropathy
Management of Bartter’s syndrome
Life long K sparing diuretic + supplementation of K and Mg
NSAIDs
