Monogenic diabetes caused by inactivating mutation(s) in the PDX1 gene, encoding pancreas/duodenum homeobox protein 1. Homozygous PDX1 mutations result in permanent neonatal diabetes. The disease is maturity-onset diabetes of the young type 4 (MONDO_0011667). Also known as: MODY type 4, MODY, type IV, MODY4, PDX1 maturity-onset diabetes of the young (disease), PDX1-associated monogenic diabetes, maturity onset diabetes of the Young, type 4, maturity-onset diabetes of the young (disease) caused by mutation in PDX1.