A Cytogenetic Study of Heavy Mental Retardates. II. A study on heavy mental retardates with behavior disorders

A cytogenetic study was made on heavy mentally retarded patients with behavior disorders. The purpose of this study was to explore the causes of mental retardation and behavior disorders. As the results, chromosome abnormalities were found in 16,1 % of the patients. This study revealed that, in the mental retardates with behavior disorders, although they were not associated with gross malformations, the chromosome abnormalities were detected with a relatively high incidence as compared with the normal population.
The 56 cases examined in this study were admitted to National Sanatorium Kamo Hospital. Their common clinical signs were heavy mental retardation and behavior disorders.
Chromosome slides were prepared in accordance with the standard blood culture procedure. Karyotype analyses were made with the application of the conventional Giemsa staining and G-, C-, and Q-banding differential staining.
Of these 56 cases, 9 cases had abnormal karyotypes, showing an incidence of 16,1 %. All the abnormal karyotype cases were autosomal abnormalities. And additional 6 cases had normal variations of no.1, 9, and Y chromosomes. The clinical and cytogenetic findings of these patients were presented.