X-linked Adrenal Hypoplasia Congenita Due to NR0B1 (DAX1) Deficiency Presenting as Severe Respiratory Distress in Near Term Infants

Acute respiratory distress in near-termneonates constitutes a medical emergency and may require ventilator support, vasopressors, inhaled nitric oxide, and in some cases, extracorporeal membrane oxygenation. We describe two infants who presented with severe respiratory distress in whom dramatic improvement occurred after they were diagnosed with adrenal failure and started on hydrocortisone. Boy BC was an African American neonate born at 36 weeks of gestation to a 20-year-old mother by C-section due to failure to progress and a failed attempt at vacuum extraction. His birth weight was 2258 g (< 10%ile), length 46 cm (< 10% ile), and head circumference (HC) 31 cm (< 10%ile). Family history was significant for the death of two maternal uncles during infancy. Pregnancy was uncomplicated and the infant required oxygen and continuous positive airway pressure (CPAP) in the delivery room. Apgar scores were 5 and 7, respectively. He developed hypothermia and hypoglycemia, and he was started on empiric antibiotics; his initial complete