Genetic linkage analysis places locus DXS250 between locus DXYS1 and locus DXS3 in Xq21.3.

@article{Epting1992GeneticLA,
  title={Genetic linkage analysis places locus DXS250 between locus DXYS1 and locus DXS3 in Xq21.3.},
  author={S Epting and Charles Schwartz},
  journal={Cytogenetics and cell genetics},
  year={1992},
  volume={60 2},
  pages={112-3}
}
The locus DXS250, which is linked to the Allan-Herndon type of X-linked mental retardation, maps between DXS3 and DXYS1 in a panel of 40 families established by the Centre d'Etude du Polymorphisme Humain, Paris.