Beating a Dead Horse? Yeah, Maybe

Once again, more published laboratory data bolster the argument that some metabolite values presented by Mark and David Geier in their studies of control and ASD children are highly questionable—and therefore, undermine the validity of their study results and, consequently, their conclusions.

A 1999 article from Melnyk S et al (anchor author Jill James) provides mean plasma thiol levels in 11 healthy adult women (Table 3) as follows. These are contrasted with the very different levels obtained by Geier et al in 2 of their studies (all values presented here are in µmol/L [either as a range or mean value ± SD]).

• In the case of plasma methionine, the published value of Melnyk et al is at least 8 times the control value of Geier et al.
• In the case of plasma cysteine, the published value of Melnyk et al is approximately 10 times the control value of Geier et al.
• In the case of GSH, the published value of Geier et al is at least 84 times that of Melnyk et al.
• In the case of GSSG, the published value of Melnyk et al is at least 3100 times that of Geier et al.

* From Geier DA, Geier MR. A clinical and laboratory evaluation of methionine cycle-transsulfuration and androgen pathway markers in children with autistic disorder. Horm Res. 2006;66:183-188. 

Transsulfuration metabolites in this study were measured at the Great Smokies Diagnostic Laboratory, a laboratory of dubious reputation. Methionine levels were originally presented in units of µmol/L. GSH values were originally presented in units of mg/dL (18-24 in children with ASD), which were then converted here to units of µmol/L for purposes of comparison (molecular weight of GSH, 307.43 µg/µmol).

** From Geier DA, Kern JK, Garver CR, Adams JB, Audhya T, Geier MR. A prospective study of transsulfuration biomarkers in autistic disorders. Neurochem Res. 2008;Jul 9. [Epub ahead of print]

Transsulfuration metabolites in this study were measured at Vitamin Diagnostics, Inc. Levels of GSSG were originally presented in units of nmol/L, which were converted here to units of µmol/L for purposes of comparison.

ASD = autism spectrum disorder; GSH = reduced glutathione; GSSG = oxidized glutathione.