Autosomal recessive variants in RFX6 cause Mitchell–Riley syndrome (OMIM, 615710; www.omim.org), characterised by intrauterine growth retardation, annular or hypoplastic pancreas, permanent neonatal diabetes, gall bladder hypoplasia or agenesis, intestinal stenosis with malabsorptive diarrhoea and, in some cases, pancreatic exocrine insufficiency [6, 8, 9]. This evidence concerns the gene RFX6 and diabetes mellitus.