Novel mutations R113X and S381F severely affect the expression of CalDAG-GEFI. Immunoblot analysis for CalDAG-GEFI (CDGI), Rasa3, Rap1, and β-actin in platelet lysates from carriers of the indicated mutations in CalDAG-GEFI. Left: p.S381F (P1 homozygous; P2, P3, P4 heterozygous); Right: p.R113X mutation (P1 and P2 homozygous; P3 heterozygous). Protein expression in lysates from healthy and unrelated controls (C) analyzed in parallel is also shown.