Leukocyte adhesion deficiency type III (LAD-III) is a form of LAD (see this term) characterized by both severe bacterial infections and a severe bleeding disorder. LAD-III is extremely rare: only 17 patients have been reported so far. Usually the first signs occur in infancy or early childhood. Patients present LAD-I life-threatening infections and a Glanzmann thrombasthenia-like bleeding disorder (see these terms). A lack of pus is observed in infected areas. LAD-III is caused by mutations in the FERMT3 gene (11q13.1), which encodes kindlin-3 in hematopoietic cells. The FERMT3 mutations lead to an activation defect of all beta-integrins. Transmission is autosomal recessive. Diagnosis is based on clinical findings and complete blood counts revealing leukocytosis with neutrophilia. Platelet aggregation assays and genetic analysis confirm the diagnosis. Differential diagnoses include LAD-I, Glanzmann thrombasthenia (see these terms), and leukemoid reaction. Antenatal diagnosis may be confirmed through biochemical or molecular analysis of chorionic villus cells. Management should focus on controlling infections and includes symptomatic treatment with antibiotics and blood transfusions. Bone marrow transplantation is the only available curative treatment option. Prognosis is poor and death occurs in early infancy if bone marrow transplantation is not performed.
Last update: May 2009