Galactosemia Transferase Deficiency

Galactose 1-phosphate uridyl transferase deficiency (galactosemia)... 

Transferase-deficiency galactosemia is more serious it is characterized by poor growth in children, speech abnormality, mental deficiency, and liver damage that may be fatal, even when galactose is withheld from the diet. Epimerase-deficiency galactosemia leads to similar symptoms, but is less severe when dietary galactose is carefully controlled. ... 

Murphy M, McHugh B, Tighe O, Mayne P, O Neill C, Naughten E, Croke DT. Genetic basis of transferase-deficient galactosemia in Ireland and the population history of the Irish Travellers. Eur J Hum Genet 1999 7 549-554. 

In addition to the classical galactosemia, there is a form of transferase deficiency that seems to result from alteration of the regulation (see Fig. 3-18) of the enzyme biosynthesis. Thus, in this form of galactosemia (referred to as the Duarte form), the homozygous have 50% and the heterozygous 75% of the normal levels of transferase activity [65]. Another form of galactosuria has been described in a few cases with normal transferase and epimerase activity but low galactokinase [66, 67]. 

T14. Severity of Clinical Symptoms Due to Enzyme Deficiency The clinical symptoms of two forms of galactosemia—deficiency of galactokinase or of UDP-glucose galactose 1-phosphate uridylyltransferase— show radically different severity. Although both types produce gastric discomfort after milk ingestion, deficiency of the transferase also leads to liver, kidney, spleen, and brain dysfunction and eventual death. What products accumulate in the blood and tissues with each type of enzyme deficiency Estimate the relative toxicities of these products from the above information. 

In the classical form of galactosemia, there is a deficiency of uridyl-transferase enzyme resulting in galactouria, cataracts, and metabolic... 

Figure 5-29. Conversion of galactose to intermediates of glucose metabolism. Galactose 1-phosphate uridyl transferase is deficient in classic galactosemia.

Deficiency of the transferase causes a more severe form of galactosemia. Symptoms include cataracts, vomiting. 

Which of the following best describes a mother with galactosemia caused by a deficiency of galactose 1-phosphate uridylyl transferase ... 

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