A gene called HAX1 is mutated in some individuals with an immunodeficiency syndrome known as severe congenital neutropenia (SCN), according to a study to be published in the January 2007 issue of Nature Genetics. The identification of mutations in HAX1 ends a 50-year search for the genetic basis of one form of this disease.
SCN comprises a group of disorders characterized by low levels of neutrophils in peripheral blood and bone marrow. As neutrophils are part of the body's defense against bacteria, affected individuals can develop life-threatening infections without treatment. The recessive form of SCN is also called Kostmann disease, after its discoverer, who identified it in 1956.
Christoph Klein and colleagues have now identified mutations in HAX1 in three Kurdish families and 19 other unrelated individuals with recessive SCN. The HAX1 protein is found in mitochondria, the energy-producing compartments of the cell, and the authors show that it is required to maintain viable neutrophils. Although recessive SCN is rare, the authors suggest that individuals with this or other forms of SCN may have mutations in other genes that normally promote the survival of neutrophils.
Christoph Klein (Hannover Medical School, Hannover, Germany)
Abstract available online.
(C) Nature Genetics press release.
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