[Investigation of chromosomal anomalies by fluorescence in-situ hybridization (fish) in Armenia].

Prenatal and postnatal molecular-cytogenetic investigations of 75 patients have been performed. 3-stage international standard of patients' examination was used, including general clinical examination, investigation by the methods of conventional cytogenetics and molecular-cytogenetic fluorescence in-situ hybridization (FISH) analysis. On the basis of cytogenetic investigation we can conclude that in 25% of cases of complex chromosomal anomalies the cytogenetic diagnosis, obtained by means of conventional karyotyping, needed further specification. Only in 50% of these cases FISH-investigations confirm the results, received on the basis of conventional cytogenetics. In other cases diagnosis was specified or changed. The investigations were carried out with consultations of Institute of Medical Genetics (University of Zurich). Some cases of chromosomal pathology, representing scientific interest, were included in the European Cytogeneticists Association Register of Unbalanced Chromosomal Aberrations (ECARUCA).

[Diagnosis of mosaic forms of karyotype anomalies in clinical cytogenetic research]. / Diagnostika mozaichnykh form anomalii kariotipa v kliniko-tsitogeneticheskikh issledovaniiakh.

Mosaicism cases have been statistically analyzed with the aim to develop a general scheme of the cytogenetic study. Using the Bernoulli formula it is shown that when P = 0.95 and proportion of clones is 10:90% and more 29 cells should be initially analyzed. If all the cells are of the same chromosomal constitution (m = 0) the mosaicism is rejected. Mosaicism is highly probable when m = 4 and more among n = 29. When m = 1, 2 or 3 the number of cells should be increased to 44 in accordance with calculations by the formula: 1--Cnm.pm.(1--p)n-m = P.