Abnormal in vitro granulopoiesis in phenotypically normal parents of some children with congenital neutropenia.

Bone marrow from hematologically normal parents of congenitally neutropenic children showed defective myeloid differentiation in vitro. In one family only the mother's marrow differentiated abnormally; in the second family both parents demonstrated abnormal myeloid differentiation. In vitro culture of bone marrow may be useful in establishing the mode of inheritance of some forms of familial neutropenia.