NR2F2 and craniofacial-deafness-hand syndrome: Thus far, the pathogenesis of CDHs is thought to be complex, involving multiple genetic factors (e.g., Wilms tumor gene (wt1) and COUP-TFII) [54,55,56], environmental toxins (e.g., herbicides and nitrogen) [57], and nutritional deficiencies (e.g., vitamin A) [58].