ESPE Abstracts

Background: We report here the case of a 5-week-old male patient, referred to the hospital because of failure to thrive. An adrenal insufficiency was diagnosed and the genetic testing showed a mutation in the DAX1 gene leading to a premature stop codon.

In addition to adrenal hypoplasia congenita, DAX1 mutation is known to be classically associated with hypogonadotrophic hypogonadism which is mostly characterized by absence of onset of puberty and infertility.

Objective and hypotheses: Our aim was to evaluate minipuberty onset in a patient with DAX1 mutation to determine if the hypothalamic–pituitary–gonadal axis is already impaired during its early life activation.

Methods: LH, FSH, and testosteron were measured by electrochemiluminescence.

Results: Physical examination of our patient showed normal male sexual differentiation (normal penile length and descended testes bilaterally). The laboratory evaluation revealed a normal minipuberty onset: serum testosterone: 0.35 μg/l at 6 weeks of age and serum testosterone: 1.9 μg/l; LH: 1.3 UI/l and FSH: 6.3 UI/l at 10 weeks of age.

Conclusion: The normal male sexual differentiation and the normal minipuberty in our patients as well as in a few patients with DAX1 mutation reported in the literature suggest that the function of the hypothalamic–pituitary–gonadal axis is normal during the perinatal period. However, absent or delayed puberty in those patients highlights the involvement of DAX1 in the central control of reproduction later in life. Based on these observations, one can hypothesize that DAX1 might not play a crucial role during the early life activation of the hypothalamic–pituitary–gonadal axis. Another explanation could be that DAX1 alteration of function at the hypothalamic-pituitary level is progressive or is partially compensated initially. This further highlights the difficulty for clinicians to predict pubertal timing and reproductive functions in patients with DAX1 mutation.