Motor neuron disease (MND) results in selective degeneration of motor neurons of the cerebral cortex, brain stem and spinal cord. It is a complex disease in the patho­genesis of which many genetic systems may be involved. A significant etiological factor of MND may be oxygen free radicals which damage neuronal cells when present in high concentrations. In detoxification processes, free radi­cals may be formed that become transformed into non toxic products. The major participants of these processes are the cytochromes P-450 CYP2E1, CYP2D6, the glutathione-S-transferases GSTM1, GSTT1, GSTP1, and the N-acetyltransferase NAT2. To investigate their role in the development of MND, we have studied polymorphisms in these genes in 75 Russian patients with MND and 105 controls. We have established a statistical distinction in frequencies of CYP2E1*1D, and GSTM1 (0/0) homozy­gotes between the patient and the control samples. Where­as the analysis of the CYP2D6, GSTT1, GSTP1 and NAT2 gene polymorphisms has revealed no differences, the GSTP1*A/GSTP1*A genotype was associated with classical upper and lower motor neuron involvement. The GSTP1*B allele was associated predominantly with  lower and upper motor neuron involvement. We propose that the genes of phases I and II of the detoxification system, CYP2E1, GSTP1, and GSTM1, participate in the development of sporadic MND in patients in Russia.

      Key words: Detoxification processes; Gene polymor­phisms; Motor neuron disease (MND)