Figure 2: Eletropherogram of the PCR product of GNAS. A) Peripheral blood leukocyte from a normal subject showing the amplification of wild allele only (arrow). B) Peripheral blood leukocyte from a patient with MAS, which the fibrodysplastic bone tissue was used as a positive control for the p.R201H mutation, showing the amplification of the mutated allele (arrow). C) Fibrodysplastic bone tissue from a patient with MAS, control for the p.201H mutation, showing the amplification of the mutated allele (arrow).