Henry Ford Hospital Medical Journal


Attempts to map the locus of the gene (MEN2A) for the multiple endocrine neoplasia type 2A (MEN-2A) syndrome over the past II years are reviewed. Lod scores from family linkage studies of polymorphisms for 26 proteins and 64 DNA markers (restriction fragment length polymorphisms or RFLPs) were pooled from the published literature and the authors' unpublished data. The pooled data excluded 32% of the genome as possible sites for the MEN2A locus. This represents a considerable increase in the area of exclusion over that of the 6% reported at the first workshop. Linkage studies of RFLPs recognized by DNA sequences from the site of the deletion at 20p2l reported in cells from patients with MEN-2A were included in the exclusions. Only two polymorphisms gave positive scores greater than 0.8, GC and one recognized by a DNA sequence from chromosome 10 but their scores were not significant. A third possible linkage was reported at this meeting using a minisatellite probe.