Structure-function features of the long-arm iso-X-chromosome of 45, X/46X, i(Xq) patients]

Differences in the morphology of the human iso-X-chromosome differentially condensed by the treatment with 5-bromodeoxyuridine were revealed by means of quantitative morphometry. It is shown that these differences are not random and are correlated with the asynchrony of the reduplication of iso-arms. It is assumed that the differences in the structural organization and in the chronology of the reproduction of iso-arms are due to the different degree of their inactivation.