Molecular haplotyping of genetic markers 10 kb apart by allele-specific long-range PCR.

Haplotypes, combinations of polymorphic markers in a chromosome, are critical for genome diversity research. However, their utility in population samplings is compromised by uncertain linkage phase determinations from unrelated individuals. Molecular haplotyping accomplishes direct phase determination by generation of hemizygous templates from diploid genomic samples. We report molecular haplotyping by allele-specific long-range PCR of two markers 9.5 kb apart at the CD4 locus: a bi-allelic Alu deletion and a multi-allelic repeat. We verified CD4 molecular haplotypes by classical Mendelian analysis. Molecular haplotyping should prove useful in mapping disease genes and in establishing founder effects.