A reader disagrees with Grammar Tips' recommendation that the term "Down syndrome" be used instead of "Down's syndrome." We cited several general-use dictionaries, a respected science writer, and a Web search (HotBot identified 16,800 matches for "Down syndrome," 7800 matches for "Down's syndrome") to support our endorsement.

Says our reader, who appends the letters JD, MD, and PhD to his name, "Dorland's Illustrated Medical Dictionary lists Down's Syndrome and not Down Syndrome. Despite all of the numbers which you cite, this is certainly more authoritative than any of the sources which you cite. In any case the better designation is trisomy 21 syndrome rather than the eponymous designation Down's Syndrome or the misnomer, mongolism."

Tomorrow's tip explains our position on the best way to proceed when the usage is not intended for readers in a professional field.