Genetic Modifiers of the GSH System

It is possible that the effectiveness of GSH supplementation in CF persons may be in part dependent upon their genetic status with reference to a gene called "GSTM1." GSTM1 is one of the family of glutathione S-transferases (GST), which enzymes allow GSH to be conjugated with harmful organic hydroperoxides and thus neutralized. It is possible to possess a genetic makeup (GSTM1-0/0) that does not allow for the production of this protein product. It has been estimated that 40-60% of the population may be homozygous for the null allele, and the health outlook for CF persons with GSTM1-0/0 is worse than for those who do not possess that genetic make-up.

Here is an article addressing this issue:

Polymorphisms in the glutathione pathway modulate cystic fibrosis severity: a cross-sectional study.
Marson FA, Bertuzzo CS, Ribeiro AF, Ribeiro JD.
BMC Med Genet. 2014 Mar 4

We also refer you to the article, by Jeremy Hull and Anne H Thomson, "Contribution of genetic factors other than CFTR to disease severity in cystic fibrosis," Thorax 1998; 53:1018-1021 "