Genetic mapping of 12 marker loci in the Xp22.3-p21.2 region

To provide a more precise genetic map of the p22.3-p21.2 region on the short arm of the human X chromosome, we performed multilocus linkage studies in an expanded database including 31 retinoschisis families and 40 normal families. Twelve loci from this region were examined. Although significant lod scores were observed between various pairs of markers by two-point linkage analysis, the confidence limits were found to be broad. The most likely gene order on the basis of multilocus analysis was Xpter-DXS89-DXS85-DXS16-(DXS207,DXS43++ +)-DXS274-(DXS41, DXS92)-ZFX-DXS164-Xcen. All other alternative orders were excluded by odds of at least 40:1.