[The relationship between polymorphisms of epidermal growth factor gene and silicosis]

To investigate the relationship between epidermal growth factor (EGF) gene polymorphisms at G-61A, R431K, and D784V and susceptibility to silicosis.

In a case-control study, 116 patients diagnosed with stage I silicosis were included in the case group, and 149 workers without silicosis of the same gender and nationality, exposed to the same nature of dust, and with similar age and cumulative time of dust exposure were included in the control group. Peripheral venous blood was collected, DNA was extracted by salting out, polymerase chain reaction-restriction fragment length polymorphism was used to identify the genotypes at three polymorphic loci of EGF and the allele frequencies, and their distributions in the case group and control group were analyzed.

The genotype frequencies of G-61A GG, GA, and AA in the case group were 50.9%, 34.5%, and 14.7%, respectively, and significant differences were found when comparing the data with those in the control group (35.6%,44.3%, and 20.1%), (χ(2) = 6.283, P = 0.048). The distribution frequencies of allele A in the case group and control group were 31.9%and 42.3%, respectively, and the difference between the two groups was statistically significant (χ2 = 5.554, P = 0.018). The risk of silicosis in workers carrying allele G at G-61A was increased by 1.564 times (OR = 1.564, 95%CI: 1.092∼2.024). The genotype frequencies of D784V AA, AT, and TT in the case group were 58.6%, 34.5%, and 6.9%, respectively, versus 65.1%, 31.5%, and 3.4% in the control group, and the differences between the two groups were not statistically significant (χ(2) = 2.278, P = 0.320). The genotype frequencies of R431K GG, GA, and AA in the case group were 56.9%, 39.7%, and 3.4%, respectively, versus 55.0%, 39.6%, and 5.4% in the control group, and the differences between the two groups were not statistically significant (χ(2) = 0.572, P = 0.751).

The EGF gene polymorphism at G-61A is associated with susceptibility to silicosis, and the risk of silicosis in dust-exposed workers carrying GG genotype is relatively high. No relationship between EGF gene polymorphisms at D784V and R431K and silicosis is found.