PT disorders

Question 1

Hereditary Renal Glucosuria mutation?

Answer 1

SGLT2 transporter

Question 2

Hereditary Renal Glucosuria clinical effect?

Answer 2

Mild to severe glucosuria with normal/low blood sugar

Question 3

Cystinuria mutation?

Answer 3

SLC3A1 or SCL7A9 transporter

Question 4

SLC3A1 transporter, transports what?

Answer 4

(COLA) = Cysteine, Ornithine, Lysine, and Arginine reabsorption

Question 5

Cystinuria clinical effect?

Answer 5

Cystine stones and cystine crystals in urine. Fairly benign, rarely leads to severe complications

Question 6

X-linked hypophosphatemic rickets mutation?

Answer 6

PHEX gene

Question 7

Mechanism of PHEX gene?

Answer 7

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

Question 8

X-linked hypophosphatemic rickets clinical effect?

Answer 8

Urinary phosphate wasting, low serum phosphorus, elevated serum alkalinity

CALCIUM NORMAL

Rickets in children
Osteomalacia in adults

Question 9

Oncogenic hypophosphatemic osteomalacia mutation?

Answer 9

Increased production of FGF-23

Question 10

Oncogenic hypophosphatemic osteomalacia effect?

Answer 10

Defect in phosphate reabsorption and Vit D production

Question 11

Hartnup disease mutation?

Answer 11

SLC6A19 defect

Question 12

SLC6A19 transports what?

Answer 12

neutral AA transporter

Question 13

Hartnup disease clinical effects?

Answer 13

“Pellegra-like” rash, failure to thrive, photosensitivity, intermittent ataxia, nystagmus, tremors

Question 14

Vit D Dependent Rickets Type 1 mutation?

Answer 14

1 alpha hydroxylase mutation

Question 15

Vit D Dependent Rickets Type 1 clinical effect?

Answer 15

hypophosphatemia and rickets

Question 16

Is Fanconi syndrome more likely to be inherited or acquired?

Answer 16

Most commonly acquired, but can be inherited

Question 17

Fanconi syndrome mechanism?

Answer 17

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

Question 18

Fanconi Syndrome metabolic abnormalities?

Answer 18

• aminoaciduria (generalized)
• Glucosuria (WITH NORMAL SERUM GLUCOSE)
• hypophosphatemia (multifactorial mechanism)
• hyperchloremic metabolic acidosis (bicarb loss)
• hypokalemia (along with natriuresis due to bicarb loss)
• uricosuria

Question 19

Most common inherited cause of fanconi syndrome?

Answer 19

Cystinosis

Question 20

2 most common acquired causes of fanconi syndrome?

Answer 20

Tenofovir, multiple myeloma