Rearrangement of one RAR-alpha gene in an acute promyelocytic leukemia case with t(15;17) and t(6;17) involving chromosomes 17 band q21.
Acute promyelocytic leukemia (APL) is a specific type of acute myelogenous leukemia characterized by a typical morphology and by a translocation between chromosomes 15 and 17, t(15;17)(q22;q21). Because this translocation is not found in other subtypes of acute myelogenous leukemias, it has become an important marker in the diagnosis and treatment of APL. Here we report a case with apparent absence of t(15;17) cells by cytogenetic techniques at diagnosis. At relapse, a metaphase FISH analysis (not dependent on chromosomal quality), followed by G-banding, was performed. t(15;17) was detected in 60% of the metaphases. In 30% of metaphases, an additional t(6;17) was detected involving the other chromosome 17 at band q21. In parallel, a molecular study (using the Southern blotting technique) was carried out and a single molecular rearrangement of the RAR-alpha gene was detected implying that RAR-alpha was not rearranged in the t(6;17) translocation.
Arranz
E
E
Department of Genetics, Fundación Jiménez Díaz, Madrid, Spain.
López
J L
JL
Robledo
M
M
Martínez
B
B
Escudero
A
A
Benítez
J
J
D000328:Adult; D015139:Blotting, Southern; D002871:Chromosome Banding; D002877:Chromosomes, Human; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D002896:Chromosomes, Human, Pair 6; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D008297:Male; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D000072482:Retinoic Acid Receptor alpha; D014178:Translocation, Genetic
C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha