Graduate student Dee Innay works in a human genome lab, whose goal is to identify the human gene responsible for a form of muscular dystrophy (MD). Dee has mapped the MD gene to a narrow interval of chromosome 9. The DNA sequence from that interval contains 6 ORFs.
The lab works with 4 different extended families in which MD is segregating and has genomic DNA samples from 35 family members that are either affected, unaffected carriers, or unaffected non-carriers. How would Dee figure out which ORF corresponds to the MD gene? (Working in humans, she cannot perform transformation rescue or use a test that relies on gene function or rescue of the mutant phenotype.)