A linkage study of multiple endocrine neoplasia type IIa.

Members of four families segregating for multiple endocrine neoplasia type IIa (Sipple's syndrome) were typed for 16 segregating blood group, erythrocyte enzyme, and plasma protein loci. Linkage analysis failed to find evidence favoring linkage between the multiple endocrine neoplasia mutation and any segregating marker. The data from this study were combined with the published data to rule out linkage for the HLA, ABO, Rh, or MNS loci at theta less than or equal to 0.25, the ADA, PGMI, AcP, GLOI, or GM loci at theta less than or equal to 0.10, and for GPT, PGD, or HpA at theta less than or equal to 0.05. The pooled data are inconclusive with respect to the previously suggested linkage to the P blood group locus.