Smith–Lemli–Opitz syndrome presenting as acute adrenal crisis in a child: a case report

BACKGROUND: Smith–Lemli–Opitz syndrome is a rare autosomal recessive disorder of cholesterol biosynthesis which is characterized by multiple congenital malformations and global developmental delay. Here we report the case of a 3-year-old, previously undiagnosed, child with Smith–Lemli–Opitz syndrome presenting with acute adrenal crisis, which is an extremely rare and atypical presentation of this disease. CASE PRESENTATION: A 3-year-old Sri Lankan Sinhalese boy without evidence of infection presented with circulatory collapse. He had a normal perinatal period; however, his early infancy was complicated by poor feeding, episodes of loose stools, failure to thrive, and several episodes of unexplained drowsiness. His weight, height, and occipitofrontal circumference were well below the third percentile. He had soft dysmorphic features that included microcephaly, bitemporal narrowing, upward slanting eyes, epicanthal folds, partial ptosis, broad nasal bridge, low set posteriorly rotated ears, high arched palate, and short neck. Marked hyperpigmentation was noted in perioral, buccal, and palmar areas. His pulses were rapid and low in volume and his systolic blood pressure was low. Initial resuscitation was performed by administering multiple crystalloid fluid boluses. A septic screen was negative. His blood glucose and serum bicarbonate levels were low and serum electrolytes revealed hyponatremia with hyperkalemia. Serum spot cortisol level was low normal and 17-hydroxyprogesterone level was low. Diagnosis of Smith–Lemli–Opitz syndrome and associated adrenal crisis was made based on clinical and biochemical features. Intravenously administered hydrocortisone was commenced to which he showed a marked clinical response. CONCLUSIONS: This case describes a rare and atypical presentation of Smith–Lemli–Opitz syndrome and highlights the importance of making early and accurate syndromic diagnoses in children with dysmorphism to avoid sudden and life-threatening complications.