Inactivation of one of the two X chromosomes in females is regulated by sequences on the X-chromosome within the
They performed a phenotype-driven genetic screen for mutations that affect X-chromosome silencing choices in mice: they screened mice from parents exposed to chemical mutagens and looked for changes in X-chromosome inactivation patterns. They then identified two mutant females that transmitted altered X inactivation patterns to early embryos. Both mutations exhibited autosomal dominant modes of inheritance. Percec