Chromosome Anomalies, Mental Deficiency, and Schizophrenia

Recent advances in cytologic techniques have opened a new horizon in the study of mental deficiency with possible bearings on schizophrenia that are examined in this paper. In 1960, the members of the Moore Clinic at the Johns Hopkins Hospital conducted a study of nuclear sex anomalies in a mental deficiency hospital (Ferguson-Smith, Johnston, and Handmaker, 1960; Johnston, Ferguson-Smith, Handmaker, Jones, and Jones, 1961). It was discovered that 3 of 784 female patients had three X chromosomes and a chromosome number of 47 instead of the usual 46. Two of 916 males had an XXXY sex-chromosome constitution with 48 chromosomes instead of 46. At that time, the present study was begun with interviews and tests on the 4 patients who were admitted to Johns Hopkins. They all rated at the mentally defective level as determined by IQ and general behavior in everyday life. In