We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleLetter: Mutation as the source of the abnormal gene for plasma cholinesterase.AuthorsSimpson, N EPublicationJournal of medical genetics, 1975, Vol 12, Issue 4, p429ISSN0022-2593Publication typeJournal ArticleDOI10.1136/jmg.12.4.429