Growth hormone and the heart in Noonan syndrome.
BACKGROUND
The clinical hallmarks of Noonan syndrome (NS) are facial dysmorphism, short stature and cardiac defects. As one of the common cardiac defects in NS is hypertrophic cardiomyopathy, there have been concerns regarding cardiac safety since the start of human growth hormone (hGH) therapy for NS.


METHODS
Review of currently available data on the prevalence of cardiac defects, the theoretical effects of hGH on the heart and the results of studies on the effects of hGH on the heart.


RESULTS
The prevalence of cardiac defects in NS is high, and the spectrum is very broad. Progression of ventricular wall thickness during hGH therapy has never been reported. There are barely any data available on children with NS and hypertrophic cardiomyopathy collected during hGH therapy. In post-marketing surveillance studies, there are no reports of adverse cardiac events related to hGH therapy.


CONCLUSIONS
The reported absence of negative effects of hGH therapy on the heart in NS and especially on ventricular wall thickness is reassuring. Still, keeping in mind the current limited experience, any effects on the heart resulting from hGH therapy should be monitored carefully in NS.
Noordam
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Department of Pediatrics, Radboud University Nijmegen Medical Centre, The Netherlands. c.noordam@cukz.umcn.nl
D000328:Adult; D002648:Child; D002675:Child, Preschool; D006330:Heart Defects, Congenital / Q000453:epidemiology; D006331:Heart Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000235:genetics; D019382:Human Growth Hormone / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D009154:Mutation; D009634:Noonan Syndrome / Q000150:complications / Q000188:drug therapy* / Q000235:genetics; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics; D019908:Proto-Oncogene Proteins c-raf / Q000235:genetics
D019382:Human Growth Hormone; D019908:Proto-Oncogene Proteins c-raf; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11