Related gene: RHOH
Inheritance pattern: Autosomal recessive
RHOH deficiency is an autosomal recessive disorder caused by variants in the Ras homolog gene family member H (RHOH) gene leading to a defect of T cell function. Affected individuals present in childhood with persistent epidermodysplasia verruciformis (flat warts-like lesions) due to persistent human papillomavirus (HPV) infection. The disorder is also associated with recurrent bronchopulmonary infections and lymphoma. While the total T cell counts are normal, those with this deficiency have impaired T cell receptor (TCR) signaling, and profound peripheral naive T cell lymphopenia with increased memory T cells. Management is directed toward medical and surgical treatment of the epidermodysplasia verruciformis lesions and prompt prevention/early diagnosis of skin cancer resulting from the malignant evolution of the skin disease.