In the classic genotype of galactosemia (including Q188R/Q188R variant of the GALT gene), there are absent or markedly reduced erythrocyte Galactose-1-phosphate uridyl transferase (GALT) enzyme activity, markedly elevated blood galactose and erythrocyte galactose-1-phosphate levels, and the patient is at risk to develop potentially lethal E. coli sepsis, as well as the long-term diet-independent complications of galactosemia. This evidence concerns the gene GALT and galactosemia.