Karyotypic abnormalities in myelofibrosis following polycythemia vera.
Polycythemia vera (PV) is a chronic myeloproliferative disease characterized by an increase of total red cell volume; in 10% to 15% of cases, bone marrow fibrosis complicates the course of the disease after several years, resulting in a hematologic picture mimicking myelofibrosis with myelocytic metaplasia (MMM). This condition is known as post polycythemic myelofibrosis (PPMF). Among 30 patients with PPMF followed in Northern France, 27 (90%) expressed one or two abnormal clones in myelocytic cell cultures. Of these, 19 (70%) had partial or complete trisomy 1q. This common anomaly either resulted from unbalanced translocations with acrocentric chromosomes, that is, 13, 14, and 15, or other chromosomes, that is, 1, 6, 7, 9, 16, 19, and Y, or from partial or total duplication of long arm of chromosome 1. A single patient had an isochromosome 1q leading to tetrasomy 1q. In all cases, a common trisomic region spanning 1q21 to 1q32 has been identified. Given that most patients had previously received chemotherapy or radio-phosphorus to control the polycythemic phase of their disease, this study illustrates the increased frequency of cytogenetic abnormalities after such treatments: 90% versus 50% in de novo MMM. Moreover, karyotype can be used to distinguish PPMF-where trisomy 1q is the main anomaly-from primary MMM where trisomy 1q is rare and deletions 13q or 20q are far more common. Whether trisomy 1q is or is not a secondary event remains a matter of debate, as well as the role of cytotoxic treatments.
Andrieux
Joris
J
Laboratoire de Génétique Médicale, Hôpital Jeanne de Flandre, Barre Nord CHRU, Lille Cedex, France. j-andrieux@chru-lille.fr
Demory
Jean Loup
JL
Caulier
Marie Thérèse
MT
Agape
Philippe
P
Wetterwald
Marc
M
Bauters
Francis
F
Laï
Jean Luc
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002877:Chromosomes, Human / Q000235:genetics / Q000648:ultrastructure; D018450:Disease Progression; D005260:Female; D006801:Humans; D007621:Karyotyping; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000150:complications* / Q000473:pathology; D055728:Primary Myelofibrosis / Q000209:etiology / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D016019:Survival Analysis