Polymorphism of the regulatory region of tumour necrosis factor alpha gene in patients with systemic lupus erythematosus.

A single-base change in the regulatory region of the tumour necrosis factor alpha (TNF-alpha) gene and the TNF2 allele said to be associated with Caucasian lupus patients has been reported. We studied this genetic polymorphism in 89 normal individuals and 67 Chinese lupus patients, 45% of whom has renal involvement. The allelic frequencies of TNF1 and TNF2 alleles in our male controls (n = 49) were 0.86 and 0.14 respectively, in the female controls (n = 40) they were 0.91 and 0.09 respectively, and as a combined group they were 0.88 and 0.12 respectively. The corresponding frequencies in our lupus patients were 0.81 and 0.19 respectively. Comparing the allelic frequencies of the combined control and patient group as well as only between the female control and female lupus patients, we did not find any association between the TNF2 allele and systemic lupus erythematosus in our cohort of Chinese patients. The TNF2 gene may be in linkage disequilibrium with the DR3 allele.