Chestnut blight is a fungal pathogen from Asia.  Over in Asia where the blight evolved together with Asian chestnuts, selective pressure conferred resistance in those species. But our North American chestnut species had little defence against the fungus.  

The fungus enters small wounds in the tree where it colonizes under the bark in cambium layer. Oxalic acid produced by the fungus kills the tissue, creating cankers. These cankers eventually girdle the tree, choking out circulation, causing the tree to die above the point of infection. 

When an Ozark chinquapin becomes infected they respond by sending up root collar sprouts (stump sprouts) around the base of the tree.  At first, the tree dies above the canker, killing the top completely but allowing stump sprouts to regrow from the base. These suckers sprouts will grow and then they are again killed back to the ground. After several cycles of this kind of attack, the tree is reduced in stature and often unable reach maturity to fruit and reproduce.

Although young trees may succumb to the disease within a year, mature trees may take years to succumb to the fungus. 

[Note: Sometimes Ozark chinquapin will have more than one trunk and this is unrelated to disease.]