Linkage between the X-linked retinitis pigmentosa locus and the L1.28 locus.

Segregation of alleles at the L1.28 locus in members of four informative families with X-linked retinitis pigmentosa was consistent with linkage between the loci for L1.28 and X-linked retinitis pigmentosa. Linkage analysis showed that the best estimate for the recombination distance in these families is 10 centimorgans. When our data are combined with the previously published linkage data, we conclude that the genetic distance between the two loci is 5 centimorgans, or approximately 5 million base pairs of DNA, with a 90% confidence interval of 1.5 to 14 centimorgans.