Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome is an inherited disorder characterized by primary immunodeficiency with dysfunction of humoral and cell-mediated immunity.

The three main symptoms of Wiskott-Aldrich syndrome are:

• Eczema or atopic dermatitis (dry, itchy and red skin)
• Abnormal and frequent bleeding (of the skin, the gums, nosebleed, bloody diarrhea, intracranial hemorrhage, etc.)
• Recurrent infections (of the skin, otitis media, pneumonia, herpes, cytomegalovirus, etc.)

It is an X-linked recessive hereditary disorder. For that reason, it primarily affects males, although females can be carriers of the disorder with no clinical signs. It is caused by mutations in a gene placed on the X chromosome (Xp11.22-23) that encodes the WASP protein. This protein has an important role in the protection against infections.

Wiskott-Aldrich syndrome is a rare disorder. It has an estimated incidence of 1 to 4 cases per 4 million males.

Wiskott-Aldrich syndrome may be suspected in children who have excessive bleeding episodes, eczema and frequent viral and bacterial infections.

A blood test usually supports the diagnosis because it usually shows:

• Thrombocytopenia (low platelet count)
• Platelets in size are smaller than normal (MPV < 6fl)

The definitive diagnostic tool is a genetic test to reveal the presence of the mutation.

Treatment of Wiskott-Aldrich syndrome is based on:

• Intravenous immunoglobulins to help strengthen the immune system.
• Infection prevention (frequent hand-washing, mask use, getting vaccinated, etc.).
• Splenectomy (spleen removal): It may reduce the bleedings but may increase the risk of infections.
• Stem cell transplant: Whenever possible it is the definitive treatment. Patients with Wiskott-Aldrich syndrome should be given prior immunosuppression to ensure that the transplant works.

The prognosis is poor but depends on each case. The life expectancy without treatment is about 10 years. However, the prognosis with stem cell transplant has improved considerably. Severe hemorrhages and serious infections are the main causes of death.