The retinoic acid receptor-alpha (RAR-α) gene was previously localized to chromosome 17q21, a region close to the t(15;17) (q22;q21) abnormality in acute promyelocytic leukemia (APL). We used the RAR-α gene as a probe and found that eight of nine APL patient samples with t(15;17) (q22;q21) showed rearranged bands. A tenth APL patient was diploid and demonstrated no rearrangement. One patient who had rearrangement as an acute leukemia did not have rearrangement in remission. The results obtained from intron/exon mapping of the RAR-α gene demonstrated that breakpoints of seven of the eight patients occurred within intron 1. Northern blot analysis of leukemic samples indicated the expression of two RAR-α mRNA of 2.7 and 3.7 kb. However, two additional mRNA of 4.1 and 3.2 kb were found in an APL patient. We conclude that the RAR-α gene is directly involved in the t(15;17) translocation in APL and may transcribe aberrant messages.
|Number of pages||5|
|Publication status||Published - 1991 Mar|