Deer in Northeast states are more susceptible to chronic wasting disease than deer in the west, where the fatal disease originated, a Penn State study found.

The study focused on 11 genetic markers that predict which deer are least vulnerable to the disease and found fewer of those markers in eastern deer.

Chronic wasting disease or CWD spreads differently in the West, where it began in Colorado in 1967, than in the east where deer congregate in higher densities.

It also affects elk, including the herd of about 1,000 in Pennsylvania.

For the study, researchers tested 2,200 deer killed in Pennsylvania, West Virginia, Virginia and Maryland and identified subpopulations where CWD is occurring.

Using DNA samples from 720 of those deer, they’ve tested the effectiveness of  the 11 markers for assessing genetic susceptibility to the disease.

David Walter, a wildlife ecologist in Penn State’s College of Agricultural Sciences, and William Miller, a professor at Calvin College, Michigan, and former doctoral student at Penn State, are preparing a method to tell whether a deer that tests positive with CWD came from a farm or the wild.