Uworld question - PRPP synthetase mutation

[voicesinmyhead]

---

Members don't see this ad.

Q id 2090 talks about a X linked mutation of prpp synthtase that causes an increased substrate concentration etc and asks about consequence?

Answer says this will cause gout through increased production of purines through feed forward activation!

Just wondering how this is possible? Wont purine synthesis (PRPP) be blocked altogether?

 

[SBR249]

The most commonly identified X-linked mutation of PRPP synthetase causes hyper-activity of the enzyme, leading to increased substrates for purine synthesis which then leads to increased purine production and degradation and thus hyperuricemia and gout. I think you may have misunderstood the question stem.