Severe Salt Wasting in a 16-day-old Male

Introduction Severe salt-wasting secondary to X-linked Adrenal Hypoplasia Congenita (X-AHC) is a rare cause reported in several cases.1,2 We present a 16-day-old male who exhibited marked hyponatremia and hyperkalemia. X-AHC was not considered based on unexpectedly elevated 11-deoxycortisol and deoxycorticostrone. Due to persistent salt wasting, additional workup was undertaken which revealed a NROB 1/DAX1 DNA sequence mutation consistent with X-AHC. Case Presentation A term 16-day-old male presented with severe electrolyte imbalance. Because of poor feeding, electrolytes were drawn which revealed: Na+ 112 mEq/L (130-145 mEq/L), K+ 6.6 mEq/L (3.7-5.9 mEq/L), and cortisol of 7.7 µg/dL ([greater than] 14 μg/dL). Both parents were healthy; a maternal half-brother was diagnosed with “Addison’s disease” at 18 mos of age requiring replacement therapy. At 21 yrs of age, he experienced an acute illness and died unexpectedly. The infant had normal appearing genitalia without hyperpigmentation. Results of an adrenal steroid panel revealed: progesterone 60 mg/dL ( The child was assumed to have 11-OH-lase Congenital Adrenal Hyperplasia (CAH) and was treated with glucocorticoid replacement. Oral salt supplementation and mineralocorticoid were used to stabilize his Na+ level, both of which were subsequently tapered and discontinued.. However, because of persistent salt-wasting and family history, additional laboratory studies were requested which revealed a NROB 1/DAX1 DNA sequence abnormality at c.1301:1 bp deletion of T: Codon: 434, consistent with a diagnosis of X–AHC. Discussion X-AHC, a rare disorder involving the development of the fetal adrenal cortex3,4, is estimated to occur in 1:140,000 to 1:1,200,000 live births. 5 Often the presentation of X-AHC is misdiagnosed as 21-OH-lase CAH due to 60% of patients presenting with early onset of adrenal failure,2 and salt wasting,1, however, severe salt wasting has been reported in newborns with 11-OH-lase CAH.6,7,8 Most reported patients have very low levels of adrenal precursors, suggesting a cholesterol side-chain cleavage enzyme deficiency or adrenal hypoplasia. This finding, in addition to a family history consistent with X-linked inheritance, generally leads to the correct diagnosis of affected males. Conclusions X-AHC should be considered in males who present with adrenal insufficiency. Although much less common than CAH, a misdiagnosis of X-AHC can result in improper management, incorrect genetic counselling, and a failure to anticipate concomitant and future co-morbidities associated with X-AHC.