In an earlier paper, positive but nonsignificant lod scores were found in pair-wise linkage tests between multiple endocrine neoplasia type 2A (MEN-2A) and both the haptoglobin (HP) locus on chromosome 16 and group-specific component (GC) locus on chromosome 4. Recently discovered restriction fragment length polymorphisms for HP and for metallothionein 2 processed pseudogene 1 (MT2P1) near GC have made it possible to carry out a more powerful set of linkage tests with MEN-2A. This paper reports the results of such linkage analyses employing both pair-wise and multipoint tests. Close linkage of HP on chromosome 16 and MEN-2A is excluded. Linkage of MEN-2A on chromosome 4 with GC is excluded on the MT2P1 side of GC in a 7-centimorgan interval around MT2P1.