I PCR out a mutated gene in a patient with Lisenbee chorea (the inability to dance in a coordinated fashion) and I compare it to another patient with that same disease phenotype. One subject had a mutation on chromosome 4, and the other subject couldn't rock it because of a mutation on chromosome 5. This is an exampe of
A.pleitropy
B.locus heterogeneity
C.allelic heterogeneity
D.dominant negative mutation
E.penetrance