{Reference Type}: Journal Article
{Title}: A Novel Homozygous RHOH Variant Associated with T Cell Dysfunction and Recurrent Opportunistic Infections.
{Author}: Zhou J;Qian M;Jiang N;Wu J;Feng X;Yu M;Min Q;Xu H;Yang Y;Yang Q;Zhou F;Shao L;Zhu H;Yang Y;Wang JY;Ruan Q;Zhang W;
{Journal}: J Clin Immunol
{Volume}: 44
{Issue}: 6
{Year}: 2024 May 22
{Factor}: 8.542
{DOI}: 10.1007/s10875-024-01735-4
{Abstract}: RHOH, an atypical small GTPase predominantly expressed in hematopoietic cells, plays a vital role in immune function. A deficiency in RHOH has been linked to epidermodysplasia verruciformis, lung disease, Burkitt lymphoma and T cell defects. Here, we report a novel germline homozygous RHOH c.245G > A (p.Cys82Tyr) variant in a 21-year-old male suffering from recurrent, invasive, opportunistic infections affecting the lungs, eyes, and brain. His sister also succumbed to a lung infection during early adulthood. The patient exhibited a persistent decrease in CD4+ T, B, and NK cell counts, and hypoimmunoglobulinemia. The patient's T cell showed impaired activation upon in vitro TCR stimulation. In Jurkat T cells transduced with RHOHC82Y, a similar reduction in activation marker CD69 up-regulation was observed. Furthermore, the C82Y variant showed reduced RHOH protein expression and impaired interaction with the TCR signaling molecule ZAP70. Together, these data suggest that the newly identified autosomal-recessive RHOH variant is associated with T cell dysfunction and recurrent opportunistic infections, functioning as a hypomorph by disrupting ZAP70-mediated TCR signaling.