Genetic analysis workshop IV: The 11P data sets

Although their exact physical locations have not been clearly resolved, the seven loci; insulin (INS), oncogene c-Ha-ras-1 (HRAS1), ADJ (D11S12), β-globin (HBBC), parathyroid hormone (PTH), calcitonin (CALC1) and catalase (CAT) have all been assigned to the short arm of chromosome 11 (Human Gene Mapping Workshop 8). Using DNA polymorphisms and 2-point linkage analysis, the linkage map: CAT - CALC1 - PTH - HBBC - D11S12 - (HRAS1:INS) was constructed with CAT being closest to the centromere. The HBBC and D11S12 loci are relatively tightly linked to the HRAS1 and INS loci. Since the HRAS1 and INS loci are only a few cM apart, it had not been possible to establish their order from family studies. Indeed, at the time that the workshop topics were selected, there were two conflicting orders published for these loci on 11p. This question of genetic order coincided with uncertainty over the precise locations of the various loci, with some studies suggesting that HBBC was on proximal 11p and others suggesting distal 11p. There was similar uncertainty on the location of INS within 11p.