Methods of stratifying a subject having or at risk for developing adolescent idiopathic scoliosis (AIS) into diagnostically or clinically useful subclasses are provided. The stratification is based on the subject's PTPμ expression and/or activity and/or PIPK1γ expression and/or activity. Also provided are methods of predicting the risk of developing a scoliosis also based on the subject's PTPμ expression and/or activity and/or PIPK1γ expression and/or activity; and methods of increasing GiPCR signaling in cells of a subject in need thereof comprising administering to the subject's cells an effective amount of an inhibitor of PIPK1γ tyrosine phosphorylation; an activator of PIPK1Y tyrosine dephosphorylation; and/or an inhibitor of PIPK1γ expression and/or activity.