PTPN11 and hypertrophic cardiomyopathy: Furthermore, expression of Shp2-Y279C, a mutation causing LS in human, recapitulated the phenotypic abnormalities seen in LS patients with signs of hypertrophic cardiomyopathy progressing to dilated cardiomyopathy and enhanced interaction of Shp2 with IRS1, and increased Akt/mTOR activity.