Noninvasive Immunohistochemical Diagnosis and Novel Mutations Causing Autosomal Dominant Tubulointerstitial Kidney Disease.

Background: Autosomal dominant tubulointerstitial kidney disease caused by mucin-1 gene () mutations (ADTKD-) is characterized by progressive kidney failure. Genetic evaluation for ADTKD- specifically tests for a cytosine duplication that creates a unique frameshift protein (MUC1fs). Our goal was to develop immunohistochemical methods to detect the MUC1fs created by the cytosine duplication and, possibly, by other similar frameshift mutations and to identify novel mutations in individuals with positive immunohistochemical staining for the MUC1fs protein.