Summary
The fragile site Xq27–28 was observed in several individuals of a large family. It is expressed at a high frequency among the carrier females, even as adults, and in one clinically normal male. None of the members of this family is affected with the mental retardation normally linked to this fragile site. Cytogenetic and flanking DNA marker polymorphism studies suggest a possible dissociation between the fragile site and clinical expression of the disease.
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Voelckel, M.A., Philip, N., Piquet, C. et al. Study of a family with a fragile site of the X chromosome at Xq27–28 without mental retardation. Hum Genet 81, 353–357 (1989). https://doi.org/10.1007/BF00283690
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DOI: https://doi.org/10.1007/BF00283690