Any maturity-onset diabetes of the young in which the cause of the disease is a mutation in the KCNJ11 gene. The disease is maturity-onset diabetes of the young type 13 (MONDO_0014589, a Monarch Disease Ontology id). Also known as: KCNJ11 maturity-onset diabetes of the young (disease), MODY type 13, MODY13, maturity-onset diabetes of the young (disease) caused by mutation in KCNJ11.