The annexinopathies: a new category of diseases

The annexins are a family of highly homologous phospholipid binding protein s, which share a four-domain structure, with one member of the family - ann exin VI - having a duplication consisting of eight domains. Thus far, ten a nnexins have been described in mammals. Although the biological functions o f the annexins have not been definitively established, two human diseases i nvolving annexin abnormalities ('annexinopathies') have been identified as of the time of writing. Overexpression of annexin II occurs in the leukocyt es of a subset of patients having a hemorrhagic form of acute promyelocytic leukemia. Underexpression of annexin V occurs on placental trophoblasts in the antiphospholipid syndrome and in preeclampsia. Also, an animal model h as been described in which annexin VII is underexpressed and is associated with disease, but the relevance of this animal model to human disease is no t yet understood. Future research is likely to elucidate additional 'annexi nopathies'. (C) 2000 Elsevier Science B.V. All rights reserved.