GALK1 and galactosemia: Early recognition and treatment with dailychenodeoxycholic acid can halt or even reverse severe neurologicalcomplications and improve prognosis.63 Galactosaemia, a rareinherited disorder of galactose metabolism screened for at birth in the UK,is caused by mutations in genes that encode enzymes of galactose.Galactokinase deficiency and classic galactosaemia are caused by mutationsin the genes of galactokinase (GALK1) andgalactose-1-phosphate (GALT), respectively (Table 3).