Elevated amino acids (Arg, Phe, Lys, bAla) in serum

Hi all,

I had a fasting serum amino acid panel done, which revealed a few items slightly outside of Quest's reference ranges. The following were high:

-Arginine: 137 umol/L (ref 43-107)
-Beta-Alanine: 7 umol/L (ref <= 5)
-Phenylalanine: 86 umol/L (ref 40-74)
-Lysine: 241 umol/L (ref 119-233)

Only one was low:
-Ethanolamine: 4 umol/L (ref 5-13)

This pattern doesn't suggest any metabolic defects according to the test. However I am just wondering if others with CFS have noted similar results. (Or, if anyone can think of a common pathway to explain this pattern of abnormalities).

Interestingly I read that hyperbetaalaninemia causes daytime somnolence, but my value is certainly not high enough to reflect the actual genetic enzyme deficiency.



  • aminos1.png
    46.8 KB · Views: 18
  • aminos2.png
    23.8 KB · Views: 18


I have had the opportunity to view a good number of LabCorp's version of this test and it is pretty common for a given individual to test slightly high or low on a handful of amino acids. Although I haven't seen results for repeat testing of the same individual, I have developed the opinion that most of these variations (unless markedly high/low) reflect the amino acid content of recent meals and the amino acids that are high or low would likely be different on repeat testing. The tests are generally designed to pick up inborn errors of protein metabolism. I would be interested to hear others experiences, but that has been mine.
Thanks Shanti1 for your reply. I think you are probably right, these seem only slightly beyond normal limits.

Interestingly, I did recently listen to a talk by Ron Davis who suggested phenylalanine is high in most of the patients he's analyzed metabolically.


Senior Member
Interesting, did he say why?
He mentioned low BH4 right after talking about the high Phe which could be a direct cause.
I am going to try a low Phe diet, Vitamin C and Folate for BH4, and I’m toying with the idea of supplementing Tyrosine and BCAA as they share a transporter with Phe. Tyrosine is synthesized from Phe by the BH4 dependent enzyme PAH. So it may make sense to take Tyrosine for at least two reasons. In following, BH4 is also necessary to make l-dopa from tyrosine which may lower dopamine and Ron indeed mentioned low dopamine in the same segment of his talk as the Phe and BH4.


Senior Member
U.S., Earth
I've only ever heard of phenylalanine being increased in BH4 deficiencies (which is one theory of ME).

In case it's relevant, tetrahydrobiopterin (BH4) is one of those compounds that is particularly vulnerable to oxidative stress. For this reason, the human body has two enzymes that can recycle oxidized BH4, and one of them is dihydrofolate reductase (DHFR), which may be familiar to some here...