OBJECTIVETo investigate the relationship between genetic polymorphism of dopamine β-hydroxylase (DBH) and manganese-induced nerve injury.

METHODSIn a cross-sectional study, 402 electric welders who had worked over one year in relatively fixed sites were recruited, and the concentration of manganese in which they worked was stable. These samples was divided into high exposure group (CEI > 1) and low exposure group (CEI < 1) by CEI. Between the two groups, the groups were divided into abnormal group and normal group according to the result of neurologic check (there were 81 workers with abnormal neurological dysfunction in high exposure group and 28 workers in low exposure group, P < 0.05). Polymorphism of DBH gene was analyzed with polymerase chain reaction-restriction fragment length polymorphism.

RESULTSThe distribution of A2A2 genotype and A2 allele of DBH was significantly different. In high exposure group, the distribution of A2A2 genotype and A2 allele of DBH in abnormal group was significantly wider than in normal group (A2A2 genotype, OR = 1.248, P < 0.05, A2 allele, OR = 1.103, P < 0.05). In low exposure group, the distribution of A2 allele of DBH in abnormal group was significantly wider than in normal group (OR = 1.176, P < 0.05).

CONCLUSIONThe individuals who carry A2A2 genotype and A2 allele of DBH have increased risk of neurological dysfunction after explosion to manganese for a certain time, which suggests that polymorphism of DBH (intron 5 Taq I) would play a great role in hereditary susceptibility of neurological dysfunction cause by manganese.