( This ( ( is ( ( an ( autosomal ( dominant disorder ) ) ) ( that ( affects ( one ( in ( 3,000 people ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (DT an) (JJ autosomal) (JJ dominant) (NN disorder)) (SBAR (WHNP (WDT that)) (S (VP (VBZ affects) (NP (NP (CD one)) (PP (IN in) (NP (CD 3,000) (NNS people))))))))) (. .)))
This is an autosomal dominant disorder that affects one in 3,000 people.
(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.