What discontinuous variant are called?

Answer 1

Rare, exceptional discontinuous variants are called mutants, whereas the more common "normal" companion phenotype is called the wild type. In many cases, the wild-type and mutant phenotypes are determined by the alleles of one gene. Mutants can occur spontaneously in nature (e.g., albinos) or they can be obtained after treatment with mutagenic chemicals or radiations. Geneticists regularly induce mutations artificially to carry out genetic analysis because mutations that affect some specific biological function under study identify the various genes that interact in that function. Note that polymorphisms originally arise as mutations, but somehow the mutant allele becomes common.