Im no expert but I will share that one of my wry neck hens who survived and had her own brood of babies one of the chicks had wry neck. Mother was never totally straightened out but was a great hen and very friendly due to the personal care I gave her. Her wry neck chick was equally cared for by me but the pullet did not survive to lay eggs or brood. She totally straightened out but some other illness took her in the end. Not sure if this is genetic or not but I bet there is a weakness in the genetics that could be passed on expressed.