PHF14 and persistent fetal circulation syndrome: In our patient both the therapy-refractory PPHN and autopsy results, showing increased musculature and fibrosis of the pulmonary vessel, point to an involvement of PHF14. Deletion of this gene has been found to cause lethal respiratory failure in mice, with histopathological examinations showing severe hypertrophy of the alveolar wall and lung fibrosis [6, 8].