Cognitive Development of Children with Sex Chromosome Abnormalities

Abstract

Sex chromosome abnormalities (SCA) are genetic disorders associated with a variety of developmental problems, including learning disorders (LD). The study of SCA provides a unique opportunity to increase understanding of genetic and developmental features of LD. Most research on the genetics of LD involves cross-sectional or retrospective study of children in order to trace familial patterns of transmission of problems of unknown cause. In contrast to such heterogeneous samples, children with LD and the same SCA share a single genetic factor. The possibility of identifying an LD subtype of specific genetic causation is thus greatly increased, especially when the study is prospective (Pennington et al., 1982). Longitudinal evaluations of children with SCA may elucidate the relationship between physical and cognitive development and help to establish the processes by which SCA is associated with LD. This knowledge in turn may increase understanding of the role of the sex chromosomes in normal cognitive development.