ABSTRACT
Characteristics of the chromosomal aberrations diagnosed in 959 prenatal tests in the II trimester of pregnancy is presented. Chromosomal aberrations were diagnosed in 33 tests (3.4%). Twenty one out of these aberrations (2.2%) were of labile character. Six aberrations resulted from the parental segregation, translocation or chromosomal inversion. In 12 cases fetus inherited stable aberration from one of parents. It amounted to 1.2% of all tested cases. Chromosomal aberrations were diagnosed in 2.7% cases tested due to the risk related to the mother's age. Half of them was trisomy of chromosome 21. Chromosomal aneuploidy in the progeny of families with a child with the same abnormality was diagnosed in 1.6% of cases. Chromosomal mosaicism was diagnosed in 2.2% of cases including 0.2% of cases with true mosaicism and 1.98% of cases with pseudomosaicism. Incidence and type of the diagnosed chromosomal aberrations coincided with foreseen aberrations for each group of the genetic risk.
Subject(s)
Amniotic Fluid/cytology , Chromosome Aberrations/genetics , Adult , Amniocentesis/methods , Chromosome Aberrations/diagnosis , Chromosome Aberrations/prevention & control , Chromosome Disorders , Female , Genetic Counseling/methods , Humans , Maternal Age , Pregnancy , Pregnancy Trimester, Second , Pregnancy, High-Risk , Risk FactorsABSTRACT
Laboratory problems and diagnostic difficulties are analysed in 1135 prenatal cytogenetic examinations of amniotic fluid cells in the Genetics Laboratory of the Mother and Child Institute. The effectiveness and the reliability of the method for the purposes of prenatal diagnosis of chromosomal aberrations were evaluated. They were comparable to those reported from other similar centres in the world.
