2020 Volume 80 Issue 6 Pages 557-562
The patient was a girl delivered by cesarean section at 36 weeks of gestation. Polyhydramnios was detected in the fetal period, and she had severe muscular hypotonia, a weak cry, and akinesia immediately after delivery. She was treated with non-invasive positive-pressure ventilation, although oxygen was not required. She had feeding problems owing to the absence of a swallowing reflex. Hence, she required tube feeding. She was a floppy infant, and her symptoms suggested a neuromuscular disease initially. Although she required mechanical ventilation and tube feeding for a long time, her hypotonia improved in a time-dependent manner, and it was a clue for suspecting Prader-Willi syndrome （PWS）. In the genetic examination, DNA methylation testing was useful for diagnosis in our patient. Considering the improvement of hypotonia in a time-dependent manner, a final diagnosis of PWS in early infancy was made.
