MPL and congenital amegakaryocytic thrombocytopenia 1: For example, c‐Mpl mutations (R102P, R464G) have been found in congenital amegakaryocytic thrombocytopenia (CAMT) patients.[10, 11, 12] These c‐Mpl mutations were blocked in the endoplasmic reticulum without the ability to translocate to the plasma membrane.