This patient was found to be homozygous for a previously unknown nonsense variant of STK4. Human STK4 (serine/threonine kinase 4) deficiency was first described in 2012 as an autosomal recessive inborn error of immunity characterized by recurrent bacterial, viral and fungal infections due to profound CD4+ T lymphopenia in the first decade of life [9, 10]. The gene discussed is STK4; the disease is fungal infectious disease.