Recombinational event between Norrie disease and DXS7 loci.

We have identified a family affected with X-linked recessive Norrie disease, in which a recombinational event occurred between the disease locus and the DXS7 locus identified by the probe L1.28. The addition of our family brings the total of published informative families to seven, with a maximum lod score of 7.58 at a recombination frequency of 0.038 +/- 0.036. This finding indicates that the L1.28 probe is useful but may not be completely reliable for prenatal diagnosis and that the gene for Norrie disease is not within the DNA sequence identified by the L1.28 probe.