Gain-of-function mutations and Loss-of-function mutations
Gain-of-function mutations is defined as mutation that results in new or increased protein function.
Gain of function mutations are dominant as one copy in a heterozygote can alter the normal phenotype.
Loss-of-function mutations is defined as mutations that results in reduced activity on protein.
Loss of function mutations are recessive as one copy in heterozygote can produce the wild or normal type phenotype.