( ( 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 ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (RB Even) (PP (IN in) (FRAG (X (NP (DT the) (CD 50)) (: -) (PP (TO to) (ADJP (JJ 60-year)))) (NP (JJ age-at-onset) (NN group))))) (, ,) (NP (DT the) (ADJP (RBS most) (JJ common)) (JJ early-onset) (NN etiology)) (VP (VBZ involves) (NP (NP (DT the) (NN inheritance)) (PP (IN of) (NP (NP (QP (CD one) (CC or) (JJR more)) (NX (NP (NN apolipoprotein) (NN E) (JJ epsilon4) (NNS alleles)) (PP (IN as) (NP (JJ susceptibility) (NNS genes))))) (CC and) (NP (ADJP (RB not) (JJ autosomal)) (JJ dominant) (NNS mutations)))))) (. .)))
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.
(ROOT (S (NP (NP (DT A) (NN person)) (VP (VBN affected) (PP (IN by) (NP (DT an) (JJ autosomal) (JJ dominant) (NN disorder))))) (VP (VBZ has) (NP (NP (CD one)) (VP (VBN mutated) (S (ADJP (JJ allele)))))) (. .)))
A person affected by an autosomal dominant disorder has one mutated allele.