[Chromosomal anomalies in children with undifferentiated forms of metal retardation based on molecular cytogenetic research data].

The results of cytogenetic diagnosis of 1333 children with mental retardation and congenital malformations are presented. Chromosomal aberrations and chromosomal variants (1qh+, 9qh+, 16qh+) have been detected in 181 (13.9%) cases analyzed and in 158 (11.85%) cases, respectively. Molecular cytogenetic methods have been used for diagnosis or detalization of diagnosis in 42 cases from 181 (23.2%). Independent variation (or polymorphism) of copies number of "classical" and alpha-satellite DNA sequences, forming pericentromeric regions (1qh+, 9qh+, 16qh+) has been detected in patients with chromosomal variants.