GATA6 haploinsufficiency causes pancreatic agenesis in humans

Abstract

Understanding the regulation of pancreatic development is key for efforts to develop new regenerative therapeutic approaches for diabetes. Rare mutations in PDX1 and PTF1A can cause pancreatic agenesis, however, most instances of this disorder are of unknown origin. We report de novo heterozygous inactivating mutations in GATA6 in 15/27 (56%) individuals with pancreatic agenesis. These findings define the most common cause of human pancreatic agenesis and establish a key role for the transcription factor GATA6 in human pancreatic development.

Figure 1. GATA6 mutations causing pancreatic agenesis

(a) Genomic and protein positions of the 14 GATA6 mutations. (b) Electrophoretic mobility shift assay showing that mutations abolish the binding to a predicted GATA6 binding sequence in the pancreatic HNF4A proximal promoter. We used nuclear extracts from cells transfected with a control vector or vectors expressing GATA6 wild-type (WT) or mutant (Mut) proteins (described at the level of the protein changes shown in fig. 1a). Only wild-type GATA6 formed a retardation complex (arrow) that disappeared after preincubation with unlabeled wild-type but not mutated double-stranded oligonucleotide probes (competitor) and with GATA6 antiserum. Identical results were observed with in vitro translated wild-type and mutant GATA6 proteins using the TFF2 GATA6 binding site (data not shown). (c) Mutated GATA6 does not activate the GATA6-responsive WNT2 promoter-luciferase gene in HeLa cells. *Statistically significant difference in activity as compared to wild type (P < 0.0001). (d) Protein blot showing comparable expression of wild-type and mutant GATA6 proteins.

Figure 2. Clinical characteristics of the pancreatic agenesis cohort

In addition to pancreatic agenesis, GATA6 mutations cause several other phenotypes. The precise malformations seen in each subject are listed in Supplementary Table 4.