PIK3R1 and Rieger anomaly: The regulatory subunit of PI3K encoded by PIK3R1 plays a crucial role in the activation of IGF-1, and heterozygous mutations in PIK3R1 are responsible for SHORT syndrome (OMIM 269880), a rare condition with its main clinical features defined by its acronym: short stature (S), hyperextensibility of joints and/or hernias (H), ocular depression (O), Rieger anomaly (R) and teething delay (T).