NR3C2 and Pelger-Huet anomaly: PHA-1 is typically divided into the following two forms based on cause: primary PHA-1, which is caused by genetic mutation of the NR3C2 gene encoding the mineralocorticoid receptor (MR) or of the epithelial sodium channel (ENaC) gene, and secondary PHA-1, which is associated with renal urinary tract abnormality.