Galactose 1-phosphate uridyltransferase

Deficiency of galactose 1-phosphate uridyltransferase produces a more severe disease because, in addition to galactosemia, galactose 1-P accumulates in the liver, brain, and other tissues. The two enzyme deficiencies are compared in Table 1-12-3. 

Galactokinase Deficiency Galactose 1-Phosphate Uridyltransferase Deflcieucy... 

Galactose 1-phosphate and UDP-glucose react to form UDP-galactose and glucose 1-phosphate, as catalyzed by galactose 1-phosphate uridyltransferase. 

Classic galactosemia is a rare, autosomal recessive disorder caused by deficiency of galactose 1-phosphate uridyltransferase. 

Elevated in deficiencies of galactokinase, galactose-1-phosphate uridyltransferase (classical galactosemia), UDP galactose-4-epimerase, and Fanconi-Bickel-syn drome, portocaval shunt, and cirrhosis, depending on time after lactose consumption. 

Levels of galactose-1-phosphate are elevated to above 100 mg/100 ml RBC in untreated galactose-1-phosphate uridyltransferase deficiency (classical galactosemia) and, to a lesser degree, in UDP galactose-4-epimerase deficiency. 

Galactose-1-phosphate uridyltransferase is the enzyme deficient in classical galacto-saemia (MIM 230 400). This disorder is caused by an impairment in the pathway step from galactose-1-phosphate to UDP-galactose. 

Table 4.6.3 Control values for galactose-1-phosphate uridyltransferase...

Table 4.7.3 Concentrations of polyols in urines of patients with metabolic disorders, as determined by method 1. Concentrations are in mmol/mol creatinine (age-controlled reference range). Bold values are above the reference range. Dist. Disturbed peak, not quantifiable due to interference from a coeluting fragment of C6-polyols, GALT galactose-1-phosphate uridyltransferase, n.d. not detectable, RPI ribose-5-phosphate isomerase, TALDO transaldolase...

Galactose 1-phosphate uridyltransferase is missing in individuals with classic galactosemia (see Figure 12.5). In this disorder, galac tose 1-phosphate and, therefore, galactose, accumulate in cells. 

A newborn boy appeared to be healthy and was discharged from the hospital. He was breast-fed by his mother. A blood sample collected for galactosemia and phenylketonuria testing per state law indicated lowered levels of galactose-1-phosphate uridyltransferase in the child s red blood cells. Discuss the following ... 

Ev pi,4-galactosyltransferase Eg pyruvate kinase E3 UDP-GIc pyrophosphorylase E4 Galactose-1-phosphate uridyltransferase E5 galactokinase... 

Then galactose-1-phosphate is transformed into the nucleotide derivative UDP-galactose. During fetal development and childhood the first step in this conversion is catalyzed by galactose-1-phosphate uridyltransferase. (The hereditary disorder galactosemia, described on p. 212, is caused by the absence of this enzyme.)... 

Berry GT, Palmieri M, Gross KC, Acosta PB, Hestenburg JA, Mazur A, Reynolds R, Segal S. The effect of dietary fruits and vegetables on urinary galactitol excretion in galactose-1-phosphate uridyltransferase deficiency. J Inherit Metab Dis 1993 16 91-100. 

Berry GT, Moate PJ, Reynolds RA, Yager CT, Ning C, Boston RY, Segal S. The rate of de novo galactose synthesis in patients with galactose-1-phosphate uridyltransferase deficiency. Mol Genet Metab 2004 81 22-30. 

Kaufman FR, Reichardt JK, Ng WG, Xu YK, Manis FR, McBride-Chang C, Wolff JA. Correlation of cognitive, neurologic, and ovarian outcome with the Q188R mutation of the galactose-1-phosphate uridyltransferase gene. J Pediatr 1994 125 225-227. 

Leshe ND, Immerman EB, Flach JE, Florez M, Fridovich-Keil JL, Elsas LJ. The human galactose-1-phosphate uridyltransferase gene. Genomics 1992 14 474-480. 

Yager C, Gibson J, States B, Elsas LJ, Segal S. Oxidation of galactose by galactose-1-phosphate uridyltransferase-defident lymphoblasts. J Inherit Metab Dis 2001 24 465-476. 

Calderon FR, et al. Mutation database for the galactose-1-phosphate uridyltransferase (GALT) gene. Hum Mutat. 2007 28(10) 939-43. 

Palmieri M, et al. Urine and plasma galactitol in patients with galactose-1-phosphate uridyltransferase deficiency galactosemia. Metabolism. 1999 48(10) 1294-302. 

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