The following information may help to address your question:
Because the body also makes some galactose, symptoms cannot be completely avoided by removing all lactose and galactose from the diet. Researchers are working on finding a treatment to lower the amount of galactose made by the body, but there is no effective method to do so at this time.
The Screening, Technology, and Research in Genetics (STAR-G) Project is a US-based organization that provides information on newborn screening. They provide comprehensive information for treatment on galactosemia. To view this information, click here.