Map of the investigated HLA region with p values of the markers used in the initial screen. Figure shows the investigated fragment of chromosome 6 comprising the previously defined WG associated region encompassing the HLA-DPB1 and RXRB genes. Vertical lines represent studied microsatellites. The lengths/heights of these lines correspond to p values after analyses in the initial screen with pooled DNA. The 4 markers, which were genotyped individually, are labelled. The p values of markers #220.127.116.11, #18.104.22.168 and #22.214.171.124 (pool analysis) could not be replicated by genotyping individually. Drawn in red is the marker (#126.96.36.199) that remained significantly different after individual genotyping. This marker has been used as a positive control (see text). For further information of fine localisation of each investigated marker and inter-marker distances see additional file 1.