ents bei make sense? r protein intake. Why might this HOA escretioa i. eeetrul a
ID: 141012 • Letter: E
Question
ents bei make sense? r protein intake. Why might this HOA escretioa i. eeetrul aad "thesae-treated alaposeria patine, ever the course of Alcaptonuria results from defects in the enzyme homogentisic acid dioxidase. As a deficiency, homogentisic acid accumulates in the body and a lot it excreted in the urine. The graph above shows the homogentisic acids levels in alcaptonuria patients that are being treated with the nitisinone vs control patients who did not get the drug. Baseod on the above, is the drug effective in shutting down this pathway? Why do you say this? ents ranged in age from 40 to 65, and all had severe arthritis and polymer deposits in their tissues. Unfortunately, the drug did not improve their conditions. Why might this be so?Explanation / Answer
Answer - Nitisinone has been shown to be effective in treatment of hereditary tyrosenima type 1 and alkaptonuria which are hereditary diseases. It is effective in reversibile inhibition of 4-Hydroxyphenylpyruvate dioxygenase (HPPD) which in turn results in non-formation of succinyl acetone which can be toxic to liver and kidneys. Also, in alkaptonuria, due to non-functioning homogentisic dioxygenase, homogenisate is build-up and leads to toxic build-up. Efficacy of nitisinone also depends on low-protien intake as when it metabolises it produces tyrosine as a side product. Thus, taking a diet with low tyrosine and derivative amino-acids is recommended.
The graph is not very clear, I cannot see the control and drug-administered responses very clearly. But looking at the graph I can suggest that the peaks have lowered down, so at some-points the HGA levels have decreased.
Patients with severe arthritis and polymer deposits shows excess HGA accumulation in tissues and joints. The arthritis has reached to advanced stage and cannot be treated but needs operative measures. Aslo nitisinone works by inhibiting formation of HGA but cannot dissolve the excess HGA deposited and stored in the tissues. In such patients, thus, nitisinone might not be as effective.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.