Help with MMA and Cysteine test results

[Pinn14]

I've posted a couple of times and I'm trying to make sense of what's going on. Total B12 was in the 'normal range' when I was tested earlier in the year but I was fortunate in that the neurologist ordered an MMA test back at the beginning of May, again in June and then July. The July test result has only just come through. Reference range for MMA is 0.10-0.42. Results were 6.17 from 2 May test then 4.80 from the 8 June test. By then I had started supplementing with oral B12 as the neurological symptoms were getting worse by the day and no one else seemed to think there was any hurry to start treatment. The good news is that the July test shows that MMA had come down 0.15 so in the normal range.

However, the letter I received from the neurologist today with the MMA result states that my cysteine level is low at 4 (normal range I think is 5-15, it's not given in the letter).

The complexity of the methylation process is taxing my brain somewhat. Is the low cysteine level something to worry about? A cursory Google search suggests a limited capacity to react to oxidative stress leading to immune problems and rapid ageing.

Any thoughts would be greatly appreciated.

[Gambit62 Administrator]

the process that recycles homocysteine into a useful building block involves both B12 and folate so it may be that your B12 levels are now adequate but your folate levels need to be higher.

B12 is used in a number of processes that go on in your cells - methylation is just one of them. Understanding everything that B12 (and folate) are involved in is hugely complicated ... I can understand bits of it but the biochemistry is incredibly complex.

[Pinn14 in reply to Gambit62]

Thanks Gambit62. Apparently homocysteine was normal (no level or range given) but cysteine was low at 4.

Homocysteine is the normal intermediate for conversion of methionine into cysteine, and thus for production of, among other things, glutathione. Unsure whether I need to do anything else other than the B12 and co factors. Do you think someone at the PA Society could help? I've recently become a member.

[Gambit62 Administrator in reply to Pinn14]

cysteine isn't something I have come across in relation to PA.

whilst it is possible that there may be a biochemist involved with the PAS that knows about cysteine this is going to be a bit of a long shot.

There do seem to be a lot of genes involved in the processing of cysteine

ghr.nlm.nih.gov/search?quer...

but not something that I could claim to even partially understand

[Pinn14 in reply to Gambit62]

Thank you. I have an appointment with a neurologist at the end of October. Hopefully he can enlighten me