Using whole-genome sequencing, researchers at the Duke University School of Medicine have identified the cause of metachondromatosis, a Mendelian disease which leads to bony growths, typically on the hands and feet. By mapping the genome of an individual in a "small family that included six individuals across four generations affected" by the condition, and by mining partial linkage data from other family members, the team was able to identify six genomic regions that were most likely to contain potentially causative mutations. With WGS, the team was able to "zero in on a tiny string of 11 base pairs deleted from exon four of a gene called PTPN11." They also found that all family members affected by metachondromatosis carried this mutation. Principal investigator David Goldstein "says the study adds to a small but growing list of examples where whole-genome sequencing approaches have successfully identified rare, high-penetrant risk factors for disease," according to a Duke press release. "The fact that linkage evidence was able to narrow our search for variants to just a fraction of what it might otherwise have been, cut our research time considerably," Goldstein said.