The Y chromosome disomy syndrome (47, XYY) in children with mental retardation, deviations of sex development and different genome anomalies: molecular cytogenetic studies

Abstract

The article present the results of retrospectively analyzed children (4424 boys) with mental and psychomotor retardation, congenital malformations and/or developmental micro anomalies. 23 children had various forms of Y chromosome dysomy syndrome. The frequency of this syndrome in the studied cohort was 0.52%; and in this connection the authors discussed the role of Y-chromosome in the origin of mental retardation. Besides, the chromosome instability in sex and somatic cells is supposed to be a common mechanism of different chromosomal anomalies. The authors discussed the possibility of cytogenetic and molecular cytogenetic diagnosis, and also clinical polymorphism of the syndrome. The authors established the necessity of molecular cytogenetic technologies in the diagnosis of different forms of the syndrome, including mosaic forms and isodicentric chromosomes-connected forms. The severity of clinical symptoms doesn’t depend on presence of regular or mosaic forms of the syndrome. The study assumes a possible connection of clinical polymorphism with mosaisism, associated with the presence of abnormal cells (cell lines) in different tissues, together with the role of Y chromosome in the origin of mental retardation in children with Y- chromosome disomy syndrome and other chromosomal anomalies. The authors underline the necessity of molecular cytogenetic diagnosis of different forms of the syndrome for correct medical and genetic consultation.