A Human Gene with a Disease Phenotype Is Going to Be

A human gene with a disease phenotype is going to be mapped by positional cloning. Which would be the MOST useful for this task?

A) information about bacterial orthologs of the gene
B) an EST database of the human genome
C) microarray data of tissues in which the gene is expressed
D) data about the inheritance of SNP markers in families with the disease
E) whole-genome-shotgun clones of the human genome