Rearrangement of chromosome no. 3 in a case of preleukemia with thrombocytosis.
The clinical and cytogenetic findings of a patient with the preleukemic syndrome and a structural rearrangement involving both chromosomes No. 3 are described. The karyotypic abnormality consisted of an insertion of a part of the long arm of one chromosome No. 3 into the other, i.e., ins(3;3)(q27;q21q27). A prominent feature of the bone marrow was a marked megakaryocytic hyperplasia. The platelet count temporarily exceeded 1000 x 10(9)/liter. The findings of the present case, together with similar observations by others, suggest that the long arm of chromosome No. 3 may contain a region involved in the regulation of megakaryopoiesis.