Ten families with fragile X syndrome: linkage relationships with four DNA probes from distal Xq.
We present clinical, cytogenetic, and linkage data of four DNA probes from the terminal long arm of the X chromosome in ten new families with fragile X syndrome. A prior/posterior method of multipoint linkage analysis is employed to combine these results with published data to refine the linkage map of terminal Xq. Ten possible probe/disease orderings were tested. The order with the greatest posterior probability (0.78) of the five loci is 52a-F9-fragile X gene-DX13-St14, although the order with reversal of the positions of 52a and F9 has a posterior probability 0.15. The mean estimates of the distances between the probes and the fragile X gene are 38 cM and 33 cM for the proximal probes 52a and F9, and 8 cM and 12 cM for the distal probes DX13 and St14. Although the current method of choice in the prenatal diagnosis and carrier detection of the fragile X syndrome remains detailed cytogenetic analysis, consideration is given to the potential role of these DNA probes, both singly and in pairs.
D002871:Chromosome Banding; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics*; D004262:DNA Restriction Enzymes; D005260:Female; D005600:Fragile X Syndrome / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D014960:X Chromosome
D005819:Genetic Markers; D004247:DNA; D004262:DNA Restriction Enzymes