D3.244 - STK4 Deficiency Presenting with Epidermodysplasia Verruciformis

Introduction: Serine/threonine kinase 4 (STK4) deficiency is a combined immunodeficiency that typically begins in the first 10 years of life. Here, a girl with STK4 deficiency is presented with genital warts.

Case presentation: A 7-year-4-month-old female patient, with consanguineous parents, admitted to our clinic due to fever and a widespread vesicular rash for the past week. She had suffered from persistent productive cough for one year. Two years ago, there was a history of hospitalization due to herpes zoster. On physical examination, the patient had widespread papular, erythematous lesions in the genital area suggestive of HPV, atopic dermatitis on the scalp, and eczema on the eyelids. Serum immunoglobulin levels were normal. Lymphopenia was detected (ALC:340mm³). The result of genital lesions biopsy consistent with epidermodysplasia verruciformis. The chest CT scan showed extensive consolidated areas, pleural effusion, and atelectatic changes. ADA enzyme levels were normal. HIV infection was rule out. There were a decreased T cell activation, increased T cell apoptosis, lymphopenia, decreased naive T cells and recent thymic emigrant levels. Whole exome sequencing revealed a homozygous pathogenic variant of the STK4 gene: NM_006282.5 c.1103delp.(Met368ArgfsTer2). The patient, who was being followed up with immunoglobulin replacement therapy and antimicrobial prophylaxis, was started on preparation for hematopoietic stem cell transplantation (HSCT).

Conclusion: Children with recurrent and treatment-resistant bacterial/viral infections should be evaluated for IEI if also especially they have accompanying lymphopenia. In this patient, prolonged genital warts, resistant eczematous lesions, and chronic lymphopenia were the most important warning signs, particularly suggestive of STK4 deficiency.