Psychiatric and developmental difficulties in 17 young females with the fragile X mutation were compared with a non-fragile X female group in a controlled study reported from the Department of Psychiatry, Division of Child and Adolescent Psychiatry, The Johns Hopkins University School of Medicine and the Kennedy Institute, Baltimore, MD. Fragile X females showed a greater frequency of avoidant, mood, and stereotypy/habit disorders than controls. They were more withdrawn and depressed and showed greater deficits in interpersonal socialization skills. The frequency of ADHD was not increased. Seven of the subjects in each group had IQs below 70. Size of DNA insertion was correlated with IQ attention problems, and anxiety/withdrawal symptoms. 
COMMENT. Contrary to previous reports, the fragile X females did not show a greater frequency of ADHD or undifferentiated attention deficit. The authors comment that the control group may have been biased for attention problems. Similar to other studies, 35% of fragile X females exhibited repetitive behaviors, compared to none of the controls. The absence of retardation among fragile X females does not protect from psychiatric and social difficulties. Sisters of fragile X males should be tested genetically by DNA analysis to provide early diagnosis and allow therapeutic intervention.