MUC1 and autosomal dominant medullary cystic kidney disease with or without hyperuricemia: For example, autosomal dominant tubulointerstitial kidney disease (ADTKD) is known to be caused by a frameshift 1 bp insertion in the VNTR in MUC1 gene, but this causal variant was not discovered until 2013 mainly due to the complex structure of the VNTR (Kirby et al., 2013).