Androgen Treatment Effects on Motor Function, Cognition, and Behavior in Boys with Klinefelter Syndrome.

Objectives: To examine the effects of early low-dose androgen on motor, cognitive, and behavioral function in prepubertal boys with Klinefelter syndrome (47,XXY).

Study Design: Double-blind trial of 84 boys, ages 4-12 years, randomized to oxandrolone (Ox; 0.06?mg/kg daily; n?=?43) or placebo (Pl; n?=?41) for 24 months. Standardized assessments were performed at baseline and every 12 months for 24 months evaluating motor, cognitive, and behavioral function.

Results: The 24-month outcomes were better in the Ox vs. Pl group on 1 of 5 primary endpoints (motor function/strength): Bruininks Visual-Motor scale (P?=?.005), without significant differences between the 2 groups for the other 4 components. Secondary analyses suggested improvement in the Ox vs. Pl group in the anxiety/depression (P?=?.03) and social problems (P?=?.01) scales on the Child Behavior Checklist, anxiety (P?=?.04) on the Piers Harris Self Concept Scale, and interpersonal problems (P?=?.02) on the Children's Depression Inventory, without significant differences in hyperactive or aggressive behaviors.

Conclusions: This double-blind, randomized trial demonstrates that 24 months of childhood low-dose androgen treatment in boys with Klinefelter syndrome benefited 1 of 5 primary endpoints (visual-motor function). Secondary analyses demonstrated positive effects of androgen on aspects of psychosocial function (anxiety, depression, social problems), without significant effects on cognitive function, or hyperactive or aggressive behaviors.

Trial Registration: ClinicalTrials.gov: NCT00348946.