Endocrine Abstracts

Background: Prader Willi Syndrome (PWS) is a disorder of genetic imprinting caused by uniparental disomy of chromosome 15. It can present in the neonatal period with dysmorphic features, hypotonia and feeding difficulties. In the UK, recombinant human Growth Hormone (rhGH) is licensed for use in PWS, improving body composition and motor development, as well as final adult height. Some studies have also demonstrated an improvement in respiratory function in children with PWS. The age at which rhGH treatment is initiated requires careful consideration of the intended benefits and risks of treatment, but is generally recommended to start by the the age of 2 years.

Aims: We describe a case of neonatal PWS, where rhGH was initiated at 16 weeks’ gestational age, with the primary aim of improving respiratory function, in an infant requiring long term non-invasive ventilation (NIV).

Case report: Infant B was the second of DCDA twins. She was delivered by emergency caesarean section at 28+1 weeks’ gestation. She displayed respiratory distress at birth and subsequently developed pulmonary haemorrhage and persistent pulmonary hypertension of the newborn, necessitating oscillatory ventilation, inhaled nitric oxide therapy and inotropic support. Following extubation to NIV, she was noted to be hypotonic with dysmorphic features. She was diagnosed with PWS at 9 weeks’ gestational age. Due to her continuing need for NIV, rhGH was initiated at 16 weeks’ gestational age. Her anthropometry moved from the 9th to the 50th centile and her tone improved. She was successfully weaned off NIV over the following 8 weeks.

Conclusion: Early genetic diagnosis of PWS enables consideration of initiation of rhGH treatment. In PWS, rhGH initiation is known to worsen respiratory compromise in those with pre-existing sleep disordered breathing. However, rhGH has also been shown to have a positive effect on respiratory function in PWS, primarily via a stimulatory effect on central respiratory centres. In addition, in this case we hypothesise that rhGH initiation in the neonatal period contributed to improved tone and thus weaning from NIV support.