D130. Blood Mosaicism, Phenotype Severity, And Tongue Reduction Surgery in Patients with Beckwith-Wedemann Syndrome: Our 13-year Experience

PURPOSE: Most patients with Beckwith-Wiedemann syndrome (BWS) have macroglossia with some cases requiring tongue reduction surgery (TRS). This study leverages our institution's 13-year experience and reports correlations among levels of affected BWS cells (mosaicism), BWS clinical score, and polysomnography findings in patients evaluated for TRS. METHODS: Levels of blood mosaicism and BWS clinical score were recorded in patients with macroglossia referred to plastic surgery for surgical evaluation. Associations between blood mosaicism, BWS clinical score, TRS, and measures of sleep apnea were assessed with appropriate statistics. RESULTS: Of the 225 patients included, BWS blood testing was available in 128 (56.9%). Mosaicism levels were higher in those who underwent TRS compared to those who did not (73.2±29.7% versus 37.9±35.9%, p<0.001). BWS clinical score was also higher in those requiring TRS (9.4±2.2 versus 7.2±1.9, p<0.001). There was a positive correlation between clinical score and obstructive apnea-hypopnea index (r=0.320, p=0.011). Receiver operating characteristic curve analysis showed a clinical score ≥11 had 100% specificity and 36.4% sensitivity for detecting patients requiring TRS. Blood mosaicism ≥80% had 63.6% sensitivity and 83.6% specificity for predicting surgery. A combined criteria of BWS clinical score ≥11 or mosaicism ≥80% had 72.7% sensitivity and 83.6% specificity for predicting TRS. CONCLUSION: Blood mosaicism levels and higher BWS clinical scores appear associated with a greater frequency of undergoing surgery in patients with macroglossia referred for surgical evaluation. Elevations in BWS clinical scoring are associated with increased OSA severity while increased blood mosaicism is not.