Glutathione S-transferase M1 and T1 polymorphisms may predict adverse effects after therapy in children with medulloblastoma

Nadia Barahmani, Sarah Carpentieri, Xio Nan Li, Tao Wang, Yumei Cao, Laura Howe, Lindsay Kilburn, Murali Chintagumpala, Ching Lau, M. Fatih Okcu

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


Glutathione S-transferases (GSTs) are polymorphic enzymes that catalyze the glutathione conjugation of alkylating agents, platinum compounds, and free radicals formed by radiation used to treat medulloblastoma. We hypothesized that GST polymorphisms may be responsible, in part, for individual differences in toxicity and responses in pediatric medulloblastoma. We investigated the relationship between GSTM1 and GSTT1 polymorphisms and survival and toxicity in 42 children with medulloblastoma diagnosed and treated at the Texas Children's Cancer Center. We conducted Kaplan-Meier analyses to determine if the GST polymorphisms were related to progression-free survival (PFS) and performed logistic regression to explore associations between GST polymorphisms and occurrence of grade 3 or greater (≥Gr 3) myelosuppression, ototoxicity, nephrotoxicity, neurotoxicity, and intellectual impairment. Patients with at least one null genotype had a 4.3 (95% confidence interval, 1.1-16.8), 3.7 (1-13.6), and 6.4 (1.2-34) times increased risk for any ≥Gr 3 toxicity, any ≥Gr 3 toxicity excluding peripheral neuropathy, and any ≥Gr 3 toxicity requiring omission or cessation of chemotherapy, respectively. Compared with all others, patients with at least one null genotype had, on average, 27.2 (p = 0.0002), 29 (p = 0.0004), and 21.7 (p = 0.002) lower full-scale, performance, and verbal intelligence quotient (IQ) scores, respectively. GSTM1 and GSTT1 polymorphisms may predict adverse events, including cognitive impairment after therapy, in patients with medulloblastoma. A larger study to validate these findings is under way.

Original languageEnglish (US)
Pages (from-to)292-300
Number of pages9
Issue number3
StatePublished - Jun 2009


  • Glutathione S-transferase polymorphisms
  • Intellectual impairment
  • Medulloblastoma
  • Pharmacogenetics
  • Toxicity

ASJC Scopus subject areas

  • Cancer Research
  • Oncology
  • Clinical Neurology


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