Application of Minisatellite DNA Probes to Linkage in MEN-2

We describe the potential benefits and the limitations of the use of highly polymorphic minisatellite DNA probes for genetic linkage analysis of multiple endocrine neoplasia type 2A (MEN-2 A). The advantage of these probes is that up to 34 loci can be examined in a single experiment, and since the loci are highly polymorphic, almost every individual in every family is informative. The disadvantage is that the DNA fragment lengths of the alleles at any given locus differ from one family to another, so that families cannot be combined, and large single sibships are needed to obtain significant linkage data. A variable DNA fragment which appears to show linkage in an initial screen of a single sibship must therefore be purified and cloned before chromosomal assignment and extension to further families is possible. These features of the probes are illustrated by a tentative linkage obtained in a large sibship with MEN-2 A