Summary

Wiskott-Aldrich syndrome (WAS) is a rare hereditary immune deficiency with recessive inheritance linked to the X chromosome (Xp11.22-p11.23). This syndrome is characterized by the association of thrombocytopenia with small-sized platelets, eczema and repeated infections. The deficiency occurs early in childhood, during the first decade and usually before the age of 3 years. Several clinical signs can orientate this diagnosis. The subject is a young boy with hemorrhagic signs (purpura, petechiae, ecchymoses, epistaxis, bloody diarrhoea or others), recurrent infections (bronchial, pulmonary), ENT (ear, nose, throat), eczema and, sometimes, signs of autoimmunity. Children with WAS should be followed in paediatric centres specialized in immunology and haematology. Management consists of treating and preventing infections. When the thrombocytopenia is very severe, splenectomy may be beneficial. Only a bone-marrow transplantation can cure this pathology. Thanks to the characterisation of the gene responsible for WAS, when the mutation has been identified in the kindred, an early antenatal diagnosis can be made at 11 weeks amenorrhea with a trophoblastic biopsy. In familial forms (more than one individual affected), polymorphic markers linked to the disease locus can also be used to evaluate the risk for a pregnant woman to transmit the disease or to perform an antenatal test.

Expert reviewer(s)

• Dr Geneviève DE SAINT-BASILE - CHAZELAS