Congenital porto-left renal venous shunt as a cause of galactosaemia.

Congenital porto left renal venous (PRV) shunt was found to be the cause of galactosaemia in four galactosaemic neonates detected by mass screening (Paigen method). The patients did not have hereditary galactosaemias and were diagnosed as having galactosaemia of unknown cause, because porto-systemic venous (PS) shunts had not been recognized. At the time of diagnosis, hypergalactosaemia was not severe (0.44-0.55 mmol/L; 8-10 mg/dl) and plasma concentration of total bile acids (TBA) did not suggest a PS shunt (46-50 micromol/L). However, slightly but consistently increased concentrations of galactose and TBA strongly suggested the presence of a PS shunt, and careful ultrasonographic investigation revealed PRV shunt. We conclude that PRV shunt should be suspected in patients with hypergalactosaemia of unknown cause.