Six single nucleotide polymorphisms (SNPs) located in the genes for interleukin-1beta (SNP: IL1B-511, +3962), tumour necrosis factor alpha (TNF-308, -238) and interleukin-6 (IL6-174, nt565) were genotyped in 303 Caucasian (Czech) patients with TJA (89 with PJI / 214 without PJI), and 168 unrelated healthy Czech individuals without TJA. Here, TNF is linked to juvenile polyposis syndrome.