LEVANIAN TRANSLOCATION : AN ENTITY AMONG TRANSLOCATIONS

Attachment of a whole chromosome to one chromatid of a non homologous chromosome is an extremely rare aberration not recognized among several categories of translocations (Borgaonkar, 1991; Schinzel). Such a rare aberration was first observed in urethane induced mitotic cells of Allium sativum L more than two decades ago (Goswami, 1983; this paper is reproduced here for ready reference as appendix of this communication). In order to "establish this type of chromosomal aberration" various other normally occurring aberrations particularly among human lymphocytes need to be extensively searched in preparations of various patients, syndromes and more particularly cancer patients, which can offer variable category of aberrations. Also, in order to recognize the validity one must repeatedly observe such variable so that it could be demonstrable. This short review presents a thorough search through examination of several thousand slides exhibiting clear spreads of chromosomes at prometaphases and metaphases. Most of these slides have been on non banded chromosome spreads and exact categorization of chromosome parts or description cannot be presented. But in order to present a fact that there are translocations involving only one chromatid and the other full / intact chromosome does not necessarily need exclusively banded metaphase plates (Figs. 1 to 7).