Rapid onset obesity and ondine’s curse: a deadly syndrome

ROHHADNET syndrome is characterized by rapid-onset-obesity, hypoventilation, hypothalamic dysregulation, autonomic dysfunction and neural tumors. A 2.4-year-old girl presented with inability to be aroused from sleep. She was obese, obtunded, hypoventilating with severe hypercarbia. Non-invasive ventilation (NIV) was started following which her sensorium, hypercarbia normalized. History revealed hyperphagia, rapidly increasing weight after 1½ year of age with normal height centiles. Hormonal profile revealed hyperprolactinemia, central hypothyroidism, suboptimal growth hormone response and normal cortisol. She had presacral tumor, pain insensitivity, fluctuating blood pressure, constipation and strabismus. ROHHADNET syndrome was clinically diagnosed based on constellation of these features. She was discharged on nocturnal NIV. Over 8 months, her hypoventilation progressed requiring tracheostomy. She also underwent excision of the presacral tumor which proved to be ganglioneuroma. Whole exome sequencing was negative for CCHS and ROHHAD genes, which could be due to somatic mosaicism; variation in the genomic region not covered by the test; or large insertions, deletions, complex rearrangements. Arriving at the diagnosis is difficult due to its overlap with other hyperphagic obesity syndromes and lack of confirmatory genetic testing.