CNDP1 and type 2 diabetes mellitus: In a further study of this locus, a leucine repeat polymorphism (D18S880) in the second exon of the carnosine dipeptidase 1 gene (CNDP1) was shown to be significantly associated with diabetic nephropathy in a relatively small number of multi-ethnic individuals (European, Arabs, and others) with type 1 or type 2 diabetes [5].