A MICROSATELLITE MARKER WITHIN THE DUPLICATED D16S79-LOCUS HAS A NULLALLELE - SIGNIFICANCE FOR LINKAGE MAPPING

The dinucleotide repeat 16AC66F3 was characterised from D16S79A within a duplicated section of 16p13.11, which is duplicated on all normal c hromosome 16's. This marker has a common null allele caused by polymor phism within one of the primer sites. A redesigned primer overcame thi s problem; however, this allowed amplification of two dinucleotide rep eats, at D16S79A and D16S79B, with an overlapping and uninterpretable distribution of alleles. Thus, 16AC66F3 marker with a null allele is p otentially useful for linkage mapping, as it avoids the ambiguity asso ciated with the genotyping of homologous AC repeats at this duplicated locus. The distribution of additional D16S79 RFLPs flanking FRA16A is clarified.