Excerpt from the busulfan drug label:
"Busulfan is clearly less effective in patients with chronic myelogenous leukemia who lack the Philadelphia (Ph1) chromosome. Also, the so-called "juvenile" type of chronic myelogenous leukemia, typically occurring in young children and associated with the absence of a Philadelphia chromosome, responds poorly to busulfan."
(For the complete drug label text with sections containing pharmacogenetic information highlighted, see the Busulfan drug label PDF.)
*Disclaimer: The contents of this page have not been endorsed by the FDA and are the sole responsibility of PharmGKB.