[An analysis of human marker chromosomes originating from chromosome 21 by using in situ hybridization].

Four cases of patients with additional marker chromosomes are described. The clinical, cytogenetic and molecular cytogenetic methods have been used for investigation. The identification of marker chromosomes was made by using in situ hybridization and the collection of chromosome-specific DNA probes.

[A review of the data from cytogenetic and molecular cytogenetic research on human supernumerary minichromosomes].

The literature about the nature of marker chromosomes (mini-chromosomes of unknown origin) in patients with mental retardation, hereditary defects of development as well as in healthy individuals is reviewed. The advantage of the use of modern molecular methods of research for the analysis of nature and origin of additional mini-chromosomes is demonstrated.

[Limited genetic monitoring in Kiev in relation to the accident at the Chernobyl Atomic Electric Power Station].

Frequency of innate developmental defects, perinatal death rate, spontaneous and induced abortions were statistically studied on the basis of primary medical information from archives of two largest maternity hospitals of Kiev for the period between 1969 and 1989. Significant variations in the chosen characters in different years were found, unidirectional changes in time being absent. No increase in the number of innate defects and frequency of spontaneous abortions after 1986 was found.

[The restriction fragment length polymorphism of the DNA loci of human chromosome 7].

The results of comparative RFLP analysis in some DNA loci of chromosome 7 in the populations of different Ukrainian regions are presented. Significant differences in RFLP-genotype distributions among regional populations are found. The role of different genetical processes which take place in the populations of different regions of the Ukraine is under discussion.