 The mucin-1 protein is involved in the creation of a mucus-like substance that coats the surface of different small tubules in the body, it is expressed on distal tubular cells in the kidney.Mucin-1 kidney disease (MKD) is caused by a mutation in the MUC1 gene.This mutation alters the genetic sequence in the MUC1 gene, resulting in a new, mutated protein, furthermore, The disease is extremely rare and its prevalence is unknown.