Inactivation pattern of the fragile X in heterozygous carriers

Abstract
In this report we present new data on BrdU‐inactivation studies in lymphocytes of five heterozygotes.The present data confirm our previous findings that the prediction of the mental status of female heterozygote carriers cannot be based on the X‐inactivation pattern. The general tendency to carry the fragile site on the active X is confirmed and the results of previous studies and hypotheses are reviewed.