Problems with the new born screen for galactosaemia.

The new born screen should identify asymptomatic children with a devastating disorder before the damage has occurred. One family had two children born with classical galactosaemia. The first child, subject to a flaw in the newborn screening program, was not detected, went into rapid liver failure and ultimately had a liver transplant. The second child was following the same devastating course when identified by the new born screen with reduced galactose-1-phosphate uridyl transferase activity in a blood spot. The rapid response of the second child to removal of lactose and galactose from the diet resulted in significant clinical improvement. If the screening test for an inborn genetic defect involves the measurement of enzyme activity in red blood cells, be sure the patient has only native red blood cells. The events leading to the failure of the galactosaemia screening test are reviewed, so physicians will be aware and avoid this problem.