Linkage and genetic counselling for the fragile X using DNA probes 52A, F9, DX13, and ST14
✍ Scribed by Mulley, John C. ;Gedeon, Agi K. ;Thorn, Kerry A. ;Bates, Lyndall J. ;Sutherland, Grant R. ;Opitz, John M. ;Reynolds, James F.
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Weight
- 708 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0148-7299
No coin nor oath required. For personal study only.
✦ Synopsis
Linkage data using the markers DXS.51, F9, DXSl.5, and DXS.52 are presented from 14 pedigrees segregating with the fragile X. Cytogenetic and DNA data were combined by twoor three-point linkage analysis for estimation of lod sc2res and carrier probabilities in potential carriers. Recombination frequencies (t) corresponding to m a x i m y z scores (2) were obtained for DXSSl (2 = 3.45, 0 =O.O): DXS15 (2 = 0.40, 0 = 0.06), F9 (2 = 3.15, 8 = 0.09), and DXS.52 (2 = 3.60, 0 = 0.11) with the fragile X. Considerable alterations to carrier probabilities occurred in some cases, especially when flanking markers were informative. The chance of mentally impaired offspring was reduced to 1 % for five of eight women with prior carrier probabilities of 32%. Three pedigrees were identified in which mutation had possibly occurred. An alternative explanation for two of these was inheritance of the fragile X from normal males and for the other inheritance from a clinically normal woman. Probabilities were computed for each of these alternatives.