X-linked adrenal hypoplasia congenita (AHC) is a rare developmental disorder of the human adrenal cortex that is caused by a mutation of the DAX-1 gene, a member of the nuclear hormone receptor superfamily. Hypogonadotrophic hypogonadism is frequently associated with this disease and the DAX-1 mutation is known to impair gonadotrophin production by acting at both the hypothalamic and pituitary levels. However, three recent studies reported that the hypothalamic-pituitary-gonadal axis was active in six infants with AHC, suggesting that a difference exists in the central regulation of hypothalamic-pituitary-gonadal activity between infant boys and pubertal boys. To determine the effect of the DAX-1 gene mutation on the axis in early childhood, we measured testosterone, LH, and FSH and performed LH-releasing hormone tests on a boy with AHC from birth to 3 years of age. Surprisingly, our findings showed that the axis was active from the infantile period to 3 years of age. This delayed initiation of the prepubertal pause, or prolonged activation of the axis, indicates that the DAX-1 gene is related to the control mechanism of the prepubertal restraint of gonadotrophin secretion.