Diagnosis of Wiskott-Aldrich Syndrome

Since Wiscott-Aldrich syndrome is characterized by a wide range of clinical manifestations, this diagnosis should be considered in all boys with bleeding, congenital or early-identified thrombocytopenia. Infections and immunological disorders may be absent or, conversely, be strongly pronounced. Some patients may develop autoimmune diseases.

According to the diagnostic consensus adopted by the ESID (European Society of Immunodeficiencies), the absolute criterion for diagnosing Wiskott-Aldrich syndrome is to detect a significant decrease in WASP protein concentration in the blood cells and / or to detect a gene mutation.

The carriers of Wiskott-Aldrich syndrome have no symptoms of the disease. The number and size of platelets, as well as the number of lymphocytes are within normal limits. In female carriers of the mutant WASP gene, non-random inactivation of the X chromosome in all hematopoietic lines, including stem cells (CD34 +), is observed. This feature is widely used in the diagnosis of the disease.

The mutation of the WASP gene can also be identified in WAS mutation carriers. Similarly, prenatal diagnosis can be performed by DNA analysis after taking a chorionic villus biopsy or from an amniocyte culture,

Differential diagnosis should be performed with idiopathic thrombocytopenic purpura, which can be both an independent disease and accompany the course of other immunodeficient conditions (eg, hyper-IgM syndrome). In addition, other X-linked diseases accompanied by thrombocytopenia, for example, X-linked thrombocytopenia with thalassemia, should be excluded. Chronic idiopathic intestinal pseudo-obstruction is also an X-linked state and is often accompanied by thrombocytopenia. X-linked congenital dyskeratosis is characterized by pigmentary disorders, leukoplakia, increased frequency of tumors, atresia of lacrimal glands, anemia and thrombocytopenia. It is assumed that this disease is a consequence of the mutation of the dyskerin gene.

Several cases of Wiskott-Aldrich syndrome in girls were described. It was found that girls with WAS symptoms were heterozygous for a mutation in the WASP gene. The authors suggested that the manifestations of Wiskott-Aldrich syndrome in girls were due to the coincidence of two events: a mutation in the WAS gene and a violation of the inactivation of the X chromosome.

Devriendt described the mutation of WASP, the result of which is severe congenital neutropenia. In this case, there was no evidence of platelet or other defects characteristic of classical WAS.

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