New insights into the genetics of congenital neutropenia.

Several congenital disorders may cause neutropenia. The recent advances in the field of molecular biology have facilitated our knowledge concerning pathophysiological mechanisms leading to these disorders. The molecular basis of disorders with defective myelopoiesis (severe congenital neutropenia and cyclic neutropenia) and disorders due to defective RNA processing (Shwachman Diamond syndrome and cartilage hair hypoplasia) are the two congenital neutropenia syndromes that are addressed in this review. Molecular defects defined by means of these disorders are very important for our understanding of the cause of the disorders as well as some unknown molecular mechanisms.