Errors of Inborn Metabolism (Heartnup Disease)

Question 1

What is the inheritance pattern of this disease and describe this disease?

Answer 1

AR inheritance, there is defective neutral amino acid transporters in the renal and intestinal epithelial cells.

Question 2

What is the main complication of Heartnup disease?

Answer 2

It will lead to pellagra, which is caused by decreased intake of tryptophan or niacin (B3).

Question 3

What does Heartnup disease cause physiologically?

Answer 3

Causes excretion of tryptophan in the urine (due to defective transporters of neutral amino acids) and decreases its absoorption from the gut.