Feeding difficulties and foregut dysmotility in Noonan's syndrome.

Abstract

Noonan's syndrome is a common dysmorphic syndrome in which failure to thrive and gastrointestinal symptoms are frequent but poorly understood. Twenty five children with Noonan's syndrome were investigated by contrast radiology, pH monitoring, surface electrogastrography (EGG), and antroduodenal manometry (ADM). Sixteen had poor feeding and symptoms of gastrointestinal dysfunction. All 16 required tube feeding. Seven of 25 had symptoms of foregut dysmotility and gastro-oesophageal reflux. In the most symptomatic children (four of seven) EGG showed fasting frequency gradient loss along the stomach fundus and pylorus with antral postprandial frequency loss. ADM showed shortened fasting cycle length, with abnormal phase III and shortened postprandial activity containing phasic contractions. Gastroduodenal motor activity was reminiscent of 32-35 week preterm patterns. The feeding difficulties appear to resolve as gut motility matures. In Noonan's syndrome, feeding problems appear to be the result of delayed gastrointestinal motor development.