Conclusion: PFIT is caused by mutations in the WDR1 gene leading to actin accumulation, pyrin activation and IL-18 release.(1) Impaired cytosqueleton homeostasis impacts hematopoietic cells especially leukocytes (resulting in immunodeficiency) and platelets (resulting in microthrombocytopenia). Here, WDR1 is linked to immunodeficiency disease.