Cardiac Arrest in a Child with Non-classic Lipoid Congenital Adrenal Hyperplasia Associated with a New STAR Gene Mutation

Abstract

Abstract Introduction: Steroidogenic acute regulatory (STAR) protein regulates steroid hormone synthesis by transporting cholesterol into mitochondria. STAR gene mutations lead to lipoid congenital adrenal hyperplasia (LCAH), the rare but most severe form of congenital adrenal hyperplasia in children. We present an unusual case with an episode of cardiac arrest in a young girl during an acute febrile illness and later she was diagnosed with adrenal insufficiency secondary to a non-classic LCAH. Case: 2-year 11-month-old previously healthy white female was brought to an urgent care clinic due to severe lethargy and a seizure-like activity during a fever illness. She was found to have an undetectable blood glucose level and went into cardiac arrest shortly after arrival. CPR was performed for approximately 11 minutes. She then developed sever respiratory distress and was intubated. She was transferred to the PICU with IV sodium bicarbonate given en route. On admission, her body weight was 13.26 kg (36.80th percentile), height 90 cm (17.56th percentile), and BMI 16.17 (62.88th percentile). Her physical exam revealed normal external female genitalia and normal skin pigmentation. Lab evaluation revealed normal sodium and potassium but elevated anion gap, hyperuricemia, elevated creatinine kinase, abnormal liver function tests and abnormal coagulation profile. Brain MRI revealed findings consistent with hypoxic-ischemic encephalopathy. Renal function improved within 24 hours and hepatic function returned to normal after 20 days. Due to her severe hypoglycemic event, a high-dose ACTH stimulation test was performed. The results were consistent with adrenal insufficiency: baseline cortisol level, 7.3 μg/dL; 30 minutes cortisol, 7.8 μg/dL; 60 minutes cortisol, 9 μg/dL (normal response, ≥18 mcg/mL at 30 or 60 minutes). The baseline ACTH level was significantly elevated, 1688 pg/mL (0–46) as well as the renin activity, 24.3 ng/hour (1.7–11.2). Genetic testing revealed a 46 XX karyotype. STAR gene analysis identified compound heterozygosity; a novel deletion (c.811delC, p.Leu271Cysfs*50) and a previously reported missense mutation (c.661G>A, p.Gly221Ser). The girl is now 11 years old and exhibits normal growth, normal cognitive development, and she has developed early signs of puberty (Tanner stage 2 for breast). She takes daily hydrocortisone, fludrocortisone and stress dose hydrocortisone as needed. Conclusion: In non-classic LACH, the onset is generally late or not acute. Initial clinical features are variable and nonspecific. For this reason, non-classic LCAH may be overlooked. Adrenal crisis is a life-threatening complication, and it is important that clinicians are aware of the clinical features of non-classic LCAH and consider it in the differential diagnoses. Genetic testing for STAR should be considered in individuals with non-autoimmune primary adrenocortical insufficiency.