Germline variants in PIK3R1 can be associated with autosomal dominant growth delay and insulin resistance (SHORT syndrome: short stature, hyperextensibility of joints/hernia, ocular depression, Rieger anomaly, and teething delay) [1,2,3] and are also described in the setting of immunodeficiency (Activated PI3K-Delta Syndrome 2, APDS2) [4]. Here, PIK3R1 is linked to immunodeficiency disease.