A lod score method for detecting linkage on the X chromosone between a marker locus and a major gene locus for a quantitative.

A sequential lod-score method is proposed for detecting linkage on the X chromosome between a marker locus and the locus of a major gene influencing a quantitative trait, The method uses information from sons of doubly heterozygous mothers. The average number of families required to detect linkage is substantially less than that of the fixed sample-size method proposed by Hill.