Unusual case of Obesity and Hypoventilation in Childhood

ABSTRACT

Objectives Childhood obesity can be monogenic or polygenic in etiology and is associated with significant morbidities. Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation, and neural crest tumor (ROHHHAD[NET]) syndrome, is a rare autonomic and respiratory pediatric disorder presenting with rapid weight gain in early childhood, hypothalamic-pituitary dysfunction, central hypoventilation, and an association with neural crest tumors. Methods A 6-year-old Asian girl with abnormal weight gain since the age of 3 years, presented to the pediatrician's office due to pulse oximeter readings in the 60s at home. Parents were monitoring saturations at home as a way of screening for COVID-19 infection. The pediatrician confirmed hypoxemia and transferred the patient to the Children's Medical Center emergency department on oxygen via EMS. She had occasional snoring and nighttime cough, but no history of respiratory distress, or signs of infection. There was no hyperphagia, neonatal hypoglycemia, or developmental or behavioral concerns. On examination her body weight was 30 kg (+1.56 SD) and height was 113 cm (-1.46 SD) with a body mass index (BMI) of 23.4 kg/m2 (+2.33 SD). No acanthosis nigricans, cushingoid features, or respiratory distress were noted on examination. In the intensive care unit, she was diagnosed with central hypoventilation requiring mechanical ventilation. Her laboratory work-up revealed central hypothyroidism (low Free T4 of 0.64 ng/dl, TSH 1.553 microIU/L). Other anterior pituitary hormones were normal (adrenocorticotropic hormone, 16.3 pg/mL;cortisol, 10.7 mug/dL;prolactin, 9.95 ng/ml;Insulin-like growth factor-1, 83 ng/mL;and IGF binding protein 3, 3.02 mg/L). Genetic investigations revealed no known mutations in the PHOX2B gene, making a diagnosis of central hypoventilation syndrome unlikely. Results Rapid onset weight gain around 3 years of age, central hypoventilation, and anterior pituitary hormone deficiency in our patient with negative PHOX2B is consistent with a clinical diagnosis of ROHHHAD[NET]. Our patient was started on levothyroxine;received tracheostomy for mechanical ventilation;and gastrostomy for pharyngeal dysphagia. She is doing well, goes to school, and is tolerating trials off the ventilator during the day. Conclusions ROHHAD is an important differential to consider for any child with rapid and early obesity and hypoventilation as early diagnosis is critical in improving the clinical management and the prognosis.