MutaGEL® r-Calcitonin kit contains a set of primer for amplification of the specific sequence within the human calcitonin receptor gene CTR. Amplificates of variing genotypes (C→T mutation, Pro463Leu polymorphism) are characterized by subsequent specific restriction enzyme digestion. The variant (C, protective) posseses a restriction site for the endonuclease whereas the other variant (T, pathogen) does not. The amplified products obtained from the protective DNA-variant will therefore be cut into two fragments, whereas the pathogen DNA-variant will not be cut. The identification of the present genotype is done by analysis of present DNA-fragments by gel electrophoretic mehtods (Dr. Essrich, Biologisches Labor, Denzlingen).