Summary
Six heterozygous carriers of a fragile site at 16q22 were available for the current study. We demonstrated that the observed fragile site was a “BrdUrd-sensitive” fra(16)(q22) or FRA16B, capable of spontaneous expression in some individuals (= “spontaneous” FRA16B). Significant differences either in spontaneous or in ethylmethane sulfonate (EMS)-induced sister chromatid exchange (SCE) frequencies were found between the fragile 16q22 site, whether expressed or not, and its homologous normal site. These data complement our previous findings on FRAXA and provide additional arguments indicating that fragility and SCE are variable cytogenetic expressions of the same DNA structural alteration.
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Lukusa, T., Meulepas, E., Fryns, J.P. et al. “Spontaneous” FRA16B is a hot spot for sister chromatid exchanges. Hum Genet 87, 583–586 (1991). https://doi.org/10.1007/BF00209017
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DOI: https://doi.org/10.1007/BF00209017