a sub population of patients such determination is useful for example to better evaluate drug efficacy and or to reduce the occurrence of potential side effects in addition once a haplotype is identified as associated with a disease or condition using either the methods of the present invention or standard population based linkage disequilibrium studies then the haplotyping assay can be used as a diagnostic to determine whether an individual suffers from the disease or condition or is at risk for developing the disease or condition such diagnostic methods are intended most preferably for humans but may also be applied in other mammalian species haplotype determinations were made by a method of the present invention for polymorphic markers present in the tnf u03b1 gene of sixteen individuals these results revealed that three of the four possible haplotypes were present in the test population and matched haplotype determinations of the same individuals using standard rflp technology with 100 concordance the tnf u03b1 gene was chosen for study because it encodes a proinflammatory cytokine associated with a broad variety of diseases such as asthma infectious diseases obesity and arthritis in addition this gene exhibits well known polymorphisms at positions u2212 308 g or a and u2212 238 g or a of the promoter region template dna was isolated from coriell cell repository camden n j subjects using the puregene u00ae dna isolation kit gentra systems inc minneapolis minn cat d 5500a the as pcr technique of the present invention was used to distinguish the four possible haplotypes for the u2212 308 and u2212 238 markers using two fluorescently labelled forward primers and two reverse primers with divergent 5 u2032 extensions fig1 a the two forward allele specific primers differentially matched the g or a allele at position u2212 308 u2212 308g or.