Patients remain symptom free on a diet devoid of fructose and sucrose. These symptoms can take on a lethal course in neonates. Later in life episodes are triggered by fasting and febrile infections. This occurs through a series of steps. Entry of galactose carbon atoms into the glycolytic pathway.
Classic galactosemia is a major symptom of two enzyme defects.
The second form of galactosemia results from a loss of galactokinase . These two defects are manifest by a failure of neonates to thrive. Vomiting and diarrhea occur following ingestion of milk, hence individuals are termed lactose intolerant . Unless controlled by exclusion of galactose from the diet, these galactosemias can go on to produce blindness and fatal liver damage. At normal circulating levels of galactose this enzyme activity causes no pathological effects.