Neutropenia with abnormal mobility of neutrophils is described in 3 related patients. All presented generalized phlebectasias; 2 had also persistent fetal circulation. One patient died at the age of 2 days from severe pulmonary hypoplasia and bilateral pneumothorax. It is speculated that the defective neutrophil mobility and the vascular abnormalities could be due to a common, genetically inherited, basic defect.