DNA linkage analysis of 26 families with fragile X syndrome

✍ Scribed by Carpenter, Nancy J.

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 594 KB
• Volume: 38
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320380229

✦ Synopsis

Linkage data using the markers F9 (factor IX), DXS15 (DX131, and DXS134 (cpX67) are presented from 26 pedigrees segregating with fragile X (fra[XI) syndrome. Cytogenetic and DNA data were combined in 2-point linkage analysis for the estimation of lod scores and carrier probabilities in potential carriers. Recombination fractions (0) corresponding to the maximum lod scores (Z) were obtained for F9(Z = 2.78,e = 0.15),DXSl05(Z = 1.72,e = 141, DXS98 (Z = 3.74, ea= O.OO), DXS52 (Z = 3.53,e = 0.171, DXSlB (Z = 4.03, 8 = 0.111, and DXS134 (Z = 2.12,e = 0.16) and for the fragile X locus (FRAXA). Recombination fractions between marker loci in the families are also presented. Discordance between the results of cytogenetic and DNA analyses in 2 potential carrier females was investigated by reexamination of the fragile site expression and was concluded to be due to the expression of the common fragile site at Xq27.2. DXSlO5 (cX55.7), DXS98 (4D-81, DXS52 (St14),