Gastric duplication cyst in an infant with Finnish-type congenital nephrotic syndrome: concurrence or coincidence?

Congenital nephrotic syndrome (CNS) is a rare disorder characterized by massive proteinuria and marked edema manifesting in utero or during the first 3 months of life. CNS can be caused by congenital infections, allo-immune maternal disease or due to the genetic defects of podocyte proteins most commonly NPHS1. Here we present a case of Finnish-type congenital nephrotic syndrome along with feeding problems and abdominal distention which was diagnosed during follow-up as a gastric-duplication cyst with a novel mutation in the nephrin gene. CNS feeding problems are attributed mainly to primary disease but in literature there are case reports of patients with CNS and hypertrophic pyloric stenosis. NPHS1 is also expressed in the stomach tissue. Physicians should be aware of this rare extra-renal manifestation or coincidence of this rare disease.