Aims To investigate the lymphatic phenotype in Noonan syndrome with reference to the medical literature

Methods Notes from patients with Noonan syndrome attending a lymphoedema clinic were located via the Geneworks database by searching for “Noonan syndrome” and then examining paper notes of those patients who had lymphoedema listed as a feature. The patients’ letters and results stored in the Electronic Patient Register were also accessed and information on lymphatic abnormalities and molecular results was gathered and analysed. Images and results of lymphoscintigraphy were obtained from iSite Enterprise.

Results 7/582 Noonan syndrome patients (1.2%) had lymphoedema listed as a characteristic, and were included in this study.

The current age of patients ranged from 6 to 37 years. Onset of lymphoedema ranged from birth to 27 years, with a mean of 10.3 years.

5/7 patients had swelling of the lower limbs and genitalia. 5/7 had systemic involvement (intestinal lymphangiectasia, chylous reflux or chylothorax). 4/7 had genital lymphorrhoea.

Conclusion This study suggests that severe lymphoedema is a less common feature of Noonan syndrome than previous reports have indicated. Mild lymphoedema in the remaining patients, however, cannot be excluded. Within the patient group studied, a consistent pattern of lymphatic abnormality was seen: lower limb lymphoedema with variable age of onset, and genital involvement with chylous reflux.