Endocrine Abstracts

Introduction: PWS results from lack of expression of genes on the paternally inherited chromosome 15q11.2-q13. Clinical manifestations include hypotonia, altered body composition, reduced growth and a high incidence of obstructive sleep apnoea (OSA). Impaired GH secretion is documented in children with PWS. Recombinant growth hormone (rGH) use poses a therapeutic challenge due to potential life threatening adverse events, namely, the theoretical risk of increased lymphoid tissue growth which can exacerbate OSA in an at risk population. The following describes what proportion of our tertiary unit’s PWS patients on rGH are receiving monitoring for sleep disordered breathing as per our local guidelines.

Audit methodology: Data was collected retrospectively by chart review on all new patients with PWS who received rGH therapy during the period from 01/01/13 to 01/07/16. Patients were divided into two groups (<2 years vs ≥2 years of age). A proforma was devised and data collected on the assessment of sleep disordered breathing pre and post rGH therapy.

Outcomes: A total of eight patients were identified. Seven charts were available for data collection. Prior to treatment, 43% (3/7) were <2 years of age. In this group, 33% (1/3) received the required overnight oximetry and capnography. This was abnormal in one patient and was and referred appropriately. 57% (4/7) were ≥2 years of age. 100% (4/4) received overnight oximetry with 75% (3/4) completing a screening sleep questionnaire. 50% (2/4) of those having both investigations had discrepant results. 100% (2/2) were referred appropriately. Post treatment initiation 100% (7/7) of patients had regular monitoring of serum IGF-1 levels at 6 and 12 months. Counselling for sleep apnoea was provided to 86% (6/7) of parents. Oxygen oximetry was performed in 86% (6/7) at 1 month, 43% (3/7) at 3 months and 43% (3/7) at 1 year. 8% (1/12) of these studies were abnormal and being referred to a specialist.

Conclusion/recommendation: Overall, monitoring for sleep disordered breathing in children with PWS before and after commencing rGH is suboptimal. Appropriate referral to specialist services is achieved. A proforma for assessing children pre and post growth hormone therapy is being devised to improve care.