Association of posterior p‐values of S.A.G.E. SIBPAL proportion‐IBD and Haseman‐Elston statistics for ACTHR112

A common practice among researchers performing linkage studies is the use of equal allele frequencies as input when reporting p‐values from computer linkage programs such as S.A.G.E. SIBPAL. Our results, using 5,000 sets from a uniform‐ prior distribution of allele frequencies, showed that such input may be problematic. Further, we found that the S.A.G.E. SIBPAL test for proportion of alleles shared identical by descent among concordantly affected sib pairs showed a greater percentage of significant p‐values with decreasing parental genotype information (Table III), while the S.A.G.E. SIBPAL Haseman‐Elston test produced significant p‐values comparatively less frequently (Table IV). © 1997 Wiley‐Liss, Inc.