Glutathione S Transferase Mutation causes low vitamin C blood level

[Jellyfish5432]

Vitamin C levels in blood are influenced by polymorphisms in glutathione S-transferases

Subjects with deletion of GST had lower vitamin C levels compared with subjects carrying the functional gene variant.

Vitamin C levels were approximately 20% lower in subjects with both functionally deficient genes in the whole group (p < 0.01) and in all non-exposed subjects (p < 0.05).

Conclusions: The correspondence of lower vitamin C levels with non-functional GST isoenzymes may indicate a causal connection between two antioxidant defence pathways, also the underlying mechanism is not yet clear

Glutathione S transferase omega recycles dehydroascorbate to ascorbate as part of the glutathione ascorbate cycle.
GSTO1 - Wikipedia
Biochemie und Pathobiochemie: Druckversion – Wikibooks, Sammlung freier Lehr-, Sach- und Fachbücher

In this reaction:
Dehydroascorbate + 2 reduced glutathione (GSH) -> Ascorbate + oxidized glutathione (GSSG)


So this gene mutation reduces vitamin C levels in the blood probably by reduced recycling via lower glutathione S transferase activity.
I think these mutations have similar relevance as the MTHFR mutation causing low folate levels.