[Karyotyping in chronic myeloproliferative syndrome (except chronic myeloid leukemia)].

Cytogenetics studies in chronic myeloproliferative disorders have brought evidence of acquired chromosomal abnormalities. Some markers are frequently seen: = 1 partial trisomy, with numerous varieties, = 7 monosomy, = 8 trisomy, = 9 trisomy, = 20 long arm deletion (20q-), and less often: iso 17q, Dq-, 6p-, 21q-. Cytogenetics studies performed during active therapy have shown various abnormalities, probably therapeutic-related. Prospectives studies are useful in order to estimate the frequency and significance of karyotype variation.