Rapamycin treatment for a child with germline PTEN mutation.

BACKGROUND: A 9-month-old boy with Proteus syndrome and a de novo germline mutation in the tumor suppressor PTEN was referred to a specialist centre for management. Over the first years of life, the patient developed life-threatening respiratory dysfunction and malnutrition because of progressive growth of hamartomas affecting the chest, mediastinum, abdomen and pelvis. INVESTIGATIONS: Physical examination, CT scans of the mediastinum, pelvis and abdomen, measurement of serum insulin-like growth factor binding protein-2, and investigation of the effect of the PTEN mutation on phosphatidylinositol 3-kinase/mammalian target of rapamycin signaling in an in vitro cell model. DIAGNOSIS: PTEN hamartoma tumor syndrome, specifically Proteus syndrome. MANAGEMENT: Oral rapamycin.