Parallelly, in the same cohort, we also evaluated the activity levels of the Galc enzyme with the HMU-bGal assay, the fluorescent substrate currently used for the clinical diagnosis of Krabbe disease [18], and highlighted the expected lack of Galc enzymatic activity [2,6] in all of the identified HOM_Twi, thus confirming the results of the novel genotyping protocol. This evidence concerns the gene GALC and Krabbe disease.