GALT and hyperinsulinemic hypoglycemia, familial, 4: Galactosaemia is a rare autosomal recessive disorder that occurs due to galactose-1-phosphate uridyl transferase (GALT) enzyme deficiency.1 The physiologic consequences of this deficiency leads to accumulation of galactose in nervous tissue, liver, lens and kidney causing severe mental retardation, liver damage and cataract formation.2 Patient with galactosaemia who has hepatic involvement, may deteriorate further by cardiac surgery under cardio-pulmonary bypass (CPB).