CD40LG and Dravet syndrome: Other studies have identified that adaptive immunity in individuals with DS is also impacted by altered AIRE expression, thymic hypoplasia, and cortical atrophy, which can collectively contribute to higher rates of apoptosis in B and T cells, more resistant T helper cells to T regulatory (Treg) cell suppression, and an altered immunoglobulin (Ig) pattern of increased IgG but decreased IgM and IgE levels [5].