What biologist uses to diagnose and treat diseases with disorders with multigenic inheritance?

Ans. B. Tag SNP(Ref: Robbins 9/epagel79)Linkage and Association StudiesThere are two primary strategies for mapping genes that cause or increase susceptibility to human disease:1. Classic linkage can be performed based on a known genetic model or, when the model is unknown, by studying pairs of affected relatives2. Disease genes can be mapped using allelic association studies (Genome Wide Association Studies, GWAS)Genome-wide association studies (GWAS) have elucidated numerous disease-associated loci and are providing novel insights into the allelic architecture of complex traits.These studies have been facilitated by the availability of comprehensive catalogues of human single-nucleotide polymorphism (SNP) haplotypes generated through the HapMap Project.The data generated by the HapMap Project are greatly facilitating GWAS for the characterization of complex disorders. Adjacent SNPs are inherited together as blocks, and these blocks can be identified by genotyping selected marker SNPs, so-called Tag SNPs, thereby reducing cost and workload.