ALZHEIMERS-DISEASE - A PISCATORIAL TREK

The evidence for linkage between Alzheimer's disease and markers on bo th chromosomes 19 and 21 [Pericak-Vance et al., 1991] by the affected- pedigree-member (APM) method [Weeks and Lange, 19881 cannot be replica ted on any of the available GAW8 data sets when marker allele frequenc ies are estimated from the combined sample. The strong dependence of t he APM method on accurate estimation of marker allele frequencies, and the effects of noninformative pairs and of genetic distance in inform ative pairs of relatives are illustrated. (C) 1993 Wiley-Liss, Inc.