Recurrent pneumonia in three patients with MECP2 duplication syndrome with aspiration as the possible cause

INTRODUCTION:Methyl-CpG binding protein 2 gene (MECP2) is located on the X chromosome (Xq28) and is important for nervous and immune system functioning. Patients with MECP2 duplication syndrome (MDS) have recurrent respiratory infections (RRIs). Although RRIs often occur with MDS because some patients with MDS also have hypoimmunoglobulinemia and duplication of the interleukin-1-receptor-associated kinase-1 gene (IRAK1), which is also located on Xq28, the phenotype of IRAK1 duplication in patients with MDS remains unclear. METHODS:The clinical course of three patients with MDS who underwent laryngotracheal separation (LTS) at two institutions was summarized. RESULTS:Three patients with MDS were identified to have recurrent pneumonia characteristic of aspiration pneumonia, sometimes requiring artificial ventilation therapy; they had no other bacterial infections. After LTS, they rarely had pneumonia. In MDS, MECP2 expression increased two-fold naturally, while IRAK-1 expression showed no difference compared with a healthy subject. CONCLUSIONS:Since RRIs in MDS are thought to be caused by aspiration and not susceptibility to infection previously estimated to be major complication, the evaluation of aspiration is recommended for RRIs for better management of MDS.