Is It Easy to Supply a Cytogenetic Diagnosis? Examples of Two Clinical Cases with Mosaicism on the 18th Chromosome
The article presents two observations with chromosomal aberrations: 1) mosaic partial monosomy of the long arm of the 18th chromosome, 29Mb in size; 2) partial monosomy of the long arm of chromosome 18, 14Mb in size, presented in two clones of cells (with deleted and ring chromosomes). The material for the study were peripheral blood cells. Clinical data, stages of a genetic diagnosis, the role of the genetic consultant in the identification of genetic pathology, research results by standard karyotyping (GTG- banding) and chromosomal microarray analysis (SNP array) are considered. Deletion of the genetic material was detected using chromosomal microarray analysis, the final karyotype was established by the combination of the results of the two methods. The possibility of revealing structural rearrangement and mosaicism by different research methods is analyzed.