New distal marker closely linked to the fragile X locus

✍ Scribed by T. J. M. Hulsebos; B. A. Oostra; S. Broersen; A. Smits; B. A. Oost; A. Westerveld

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 468 KB
• Volume: 87
• Category: Article
• ISSN: 0340-6717
• DOI: 10.1007/bf00200922

✦ Synopsis

We have isolated II-10, a new X-chromosomal probe that identifies a highly informative two-allele TaqI restriction fragment length polymorphism at locus DXS466. Using somatic cell hybrids containing distinct portions of the long arm of the X chromosome, we could localize DXS466 between DXS296 and DXS304, both of which are closely linked distal markers for fragile X. This regional localization was supported by the analysis, in fragile X families, of recombination events between these three loci, the fragile X locus and locus DXS52, the latter being located at a more distal position. DXS466 is closely linked to the fragile X locus with a peak lod score of 7.79 at a recombination fraction of 0.02. Heterozygosity of DXS466 is approximately 50%. Its close proximity and relatively high informativity make DXS466 a valuable new diagnostic DNA marker for fragile X.