sentence2_structure: A person<>affected<>by an autosomal dominant disorder$$$A person affected by an autosomal dominant disorder<>has<>one mutated allele
sentence1: Even in the 50- to 60-year age-at-onset group, the most common early-onset etiology involves the inheritance of one or more apolipoprotein E epsilon4 alleles as susceptibility genes and not autosomal dominant mutations.
sentence2: A person affected by an autosomal dominant disorder has one mutated allele.
question: What is needed for a person to be affected by an autosomal dominant disorder?