ABSTRACT
Galactosemia is an inborn error of carbohydrate metabolism that results from deficiency of galactose-1-phosphate uridyl transferase (EC 2.7.7.12) (Figure 58.1). The disorder was first described in 1935 by Mason and Turner [1]. They found the reducing sugar in the urine and characterized it chemically as galactose. It is now clear that galactosuria may occur also in galactokinase deficiency, and in uridinediphosphate-4epimerase deficiency. The enzyme deficiency was discovered by Isselbacher and colleagues [2]. The pathway of galactose metabolism had been worked out just after a few years earlier by Leloir and by Kalckar and their colleagues [3,4]. The first step in the utilization is its conversion to galactose-1phosphate (Gal-1-P) [5], which is catalyzed by galactokinase.
where ATP adenosine triphosphate; ADP adenosine diphosphate.
