The congenital intrahepatic arterioportal fistula syndrome: elucidation and proposed classification.

Congenital intrahepatic arterioportal fistula is a rare but treatable cause of portal hypertension for which early recognition may lead to successful radiological management. We report an infant presenting with severe failure to thrive, melena and splenomegaly due to a congenital intrahepatic arterioportal fistula, successfully ablated after multiple trials of superselective transarterial embolization. Comprehensive review of congenital cases provides an understanding of the key clinical features defining this syndrome. A classification system is proposed, upon which treatment decisions may be based.

Mutations in the proenteropeptidase gene are the molecular cause of congenital enteropeptidase deficiency.

Enteropeptidase (enterokinase [E.C.3.4.21.9]) is a serine protease of the intestinal brush border in the proximal small intestine. It activates the pancreatic proenzyme trypsinogen, which, in turn, releases active digestive enzymes from their inactive pancreatic precursors. Congenital enteropeptidase deficiency is a rare recessively inherited disorder leading, in affected infants, to severe failure to thrive. The genomic structure of the proenteropeptidase gene (25 exons, total gene size 88 kb) was characterized in order to perform DNA sequencing in three clinically and biochemically proved patients with congenital enteropeptidase deficiency who were from two families. We found compound heterozygosity for nonsense mutations (S712X/R857X) in two affected siblings and found compound heterozygosity for a nonsense mutation (Q261X) and a frameshift mutation (FsQ902) in the third patient. In accordance with the biochemical findings, all four defective alleles identified are predicted null alleles leading to a gene product not containing the active site of the enzyme. These data provide first evidence that proenteropeptidase-gene mutations are the primary cause of congenital enteropeptidase deficiency.