No Evidence for Linkage Between Diabetes and the Kidd Marker

We have studied linkage analysis between the Kidd (Jk) red blood cell marker locus and insulin-dependent diabetes mellitus (IDD) in an attempt to confirm the preliminary report of Hodge et al. One hundred thirtytwo families with one IDD proband (67 simplex and 65 multiplex families) were analyzed using the LIPED computer program and assuming three genetic models (autosomal recessive, additive, and dominant) with parameters similar to those used by Hodge et al. The lod scores at zero recombination were −18.51, −11.62, and −6.03 for the recessive, additive, and dominant models, respectively. These results constitute significant evidence against tight linkage between Kidd and IDD, while providing no evidence for looser linkage, and are in contrast with the positive lod scores found by Hodge et al. in a different population.