Trisomy 8 in acute promyelocytic leukaemia: an interphase study by fluorescence in situ hybridization.
Acute promyelocytic leukaemia (APL) is characterized by t(15;17)(q24;q21). Trisomy 8 is the commonest accompanying karyotypic aberration. We investigated 14 APL patients for trisomy 8 using fluorescence in situ hybridization (FISH). Conventional cytogenetic analysis showed trisomy 8 in two of nine successfully karyotyped cases. With FISH, a possible third case showing a subclone (1-2.5%) with trisomy 8 was found. The trisomy 8 clone size defined by karyotyping and FISH was concordant in one case and discordant in another, in which trisomy 8 was found in 100% of metaphases but only in 48% of leukaemic promyelocytes by FISH. Therefore trisomy 8 was mosaic in all the cases, suggesting that it had arisen from clonal evolution. All-trans-retinoic acid successfully induced morphologic remission in both cases with trisomy 8.
Kwong
Y L
YL
University Department of Medicine, Queen Mary Hospital, Hong Kong.
Wong
K F
KF
Chan
T K
TK
D000328:Adult; D000368:Aged; D002675:Child, Preschool; D002898:Chromosomes, Human, Pair 8; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D014314:Trisomy