Treatment of congenital adrenal hyperplasia and Klinefelter Syndrome with central precocious puberty: a case report

The simultaneous occurrence of Klinefelter syndrome (KS) and congenital adrenal hyperplasia (CAH) is extremely rare, as the former causes androgen deficiency, while the latter results in androgen excess. In addition, central precocious puberty (CPP) will occur, which is caused by the activation of the hypothalamic-pituitary-gonadal (HPG) axis by androgens. We present the 7th reported case of simultaneous KS and CAH in a boy with CPP due to protopathy of CAH. He presented with increased gonadotropin and excessive androgen levels, and was diagnosed with KS due to his unexpected karyotype analysis results. This is the first reported case of an association between KS and CAH to undergo gonadotropin-releasing hormone analog (GnRHa) and recombinant human growth hormone (rhGH) therapy to increase his predicted final height. His predicted adult height was approximately 160 cm by estimation using the bone age as well as current height, which is much taller than the estimated height before treatment. Although KS may cause hypogonadism, the patient should be administered GnRHa and rhGH therapy if simultaneous CAH, CPP, and KS are present to increase the patient’s predicted final height. Excessive androgen levels may mask the symptoms of KS-related hypogonadism during childhood; however, the patient should be made aware of the possibility of hypogonadism developing in the future.