We studied the genetic and clinical features of diabetic subjects in a 5-generation Michigan-Kentucky pedigree ascertained through a proband with pancreatic agenesis and homozygous for the IPF1 mutation Pro63fsx60.
In contrast to other reported PDX1 mutations leading to neonatal diabetes and pancreas agenesis, homozygosity for the E178G mutation was not associated with clinical signs of exocrine pancreas insufficiency.
In humans and other animal species, the embryonic development of the pancreas requires PDX-1, as demonstrated by the identification of an individual with pancreatic agenesis resulting from a mutation that impaired the transcription of a functionally active PDX-1 protein.
In addition, cerebellar hypoplasia and Walcott-Rallison syndrome have been associated with PNDM, suggesting an autosomal recessive inheritance pattern; furthermore, a mutation in the gene insulin promoter factor 1 has been identified as a cause of pancreatic agenesis in PNDM.
We conclude that mutations in the IPF-1 gene may predispose to type 2 diabetes and are a rare cause of MODY and pancreatic agenesis, with the phenotype depending upon the severity of the mutation.