Oscar, the 5a THF/5b THF ratio (or in inverted form with appropriate range) is the one Crisler and many other doctors cite as being the most sensitive and reliable from a diagnostic standpoint. The Chinese paper clearly indicates that one of the other ratios is not sensitive to the condition (don’t feel like looking up that portion of the paper at the moment).
Look, if half our urinary metabolite ratios are low it must mean something, e.g. gene expression at a minimum, possible damage to one or more of the 19 genes that encode SRD5AR2 at the maximum. The men being studied were born with ambiguous genitilia via mutation of the genes at birth/due to inbreeding etc. Therefore they are worse, as exemplified by very low DHT levels (mine and many others are normal or at least mid range). I can not agree with your conclusion just because some of us have 5a metabolites that are not “unambiguously low” via serum testing doesn’t mean the urine ratios aren’t a marker of something wrong. I have further information here I can PM you if you would like.
Mariobros, ever try to get an academic research lab to actually run the genital skin fibroblast testing? I mean one that knows how - they aren’t interested outside of doing it within a research grant setting due to “human subject” regulations/red tape etc. This has been my experience thus far, if anyone has found a lab willing to do this for a reasonable amount of money please let me know.