PT disorders Flashcards
Hereditary Renal Glucosuria mutation?
SGLT2 transporter
Hereditary Renal Glucosuria clinical effect?
Mild to severe glucosuria with normal/low blood sugar
Cystinuria mutation?
SLC3A1 or SCL7A9 transporter
SLC3A1 transporter, transports what?
(COLA) = Cysteine, Ornithine, Lysine, and Arginine reabsorption
Cystinuria clinical effect?
Cystine stones and cystine crystals in urine. Fairly benign, rarely leads to severe complications
X-linked hypophosphatemic rickets mutation?
PHEX gene
Mechanism of PHEX gene?
PHEX gene down regulates FGF-23 (which negatively inhibits Na-Pi transporter. Mutation in it therefore up regulates FGF-23, preventing phosphate transport into cell
X-linked hypophosphatemic rickets clinical effect?
Urinary phosphate wasting, low serum phosphorus, elevated serum alkalinity
CALCIUM NORMAL
Rickets in children
Osteomalacia in adults
Oncogenic hypophosphatemic osteomalacia mutation?
Increased production of FGF-23
Oncogenic hypophosphatemic osteomalacia effect?
Defect in phosphate reabsorption and Vit D production
Hartnup disease mutation?
SLC6A19 defect
SLC6A19 transports what?
neutral AA transporter
Hartnup disease clinical effects?
“Pellegra-like” rash, failure to thrive, photosensitivity, intermittent ataxia, nystagmus, tremors
Vit D Dependent Rickets Type 1 mutation?
1 alpha hydroxylase mutation
Vit D Dependent Rickets Type 1 clinical effect?
hypophosphatemia and rickets
Is Fanconi syndrome more likely to be inherited or acquired?
Most commonly acquired, but can be inherited
Fanconi syndrome mechanism?
Multiple possibly mechanisms, varying with underlying cause. Examples include:
- defective binding of Na with transport proteins
- defective insertion of carriers into brush border membrane
- inhibited or abnormal Na-K-ATPase
- impaired mitochondrial energy generation
Fanconi Syndrome metabolic abnormalities?
- aminoaciduria (generalized)
- Glucosuria (WITH NORMAL SERUM GLUCOSE)
- hypophosphatemia (multifactorial mechanism)
- hyperchloremic metabolic acidosis (bicarb loss)
- hypokalemia (along with natriuresis due to bicarb loss)
- uricosuria
Most common inherited cause of fanconi syndrome?
Cystinosis
2 most common acquired causes of fanconi syndrome?
Tenofovir, multiple myeloma
