Human galactocerebrosidase, the enzyme deficient in Krabbe disease, was 
purified, through several hydrophobic column steps and gel filtration, 
22,650-fold from human lymphocytes. Using information on its N-terminal and 
internal amino acid sequences, and the polymerase chain reaction method, we 
cloned a full-length cDNA for the enzyme. The deduced amino acid sequence 
matched all amino acid sequences determined. The 3780 nucleotide sequence 
included 2007 nucleotides which encoded a single chain peptide of 669 amino acid 
residues with a 26 amino acid N-terminal signal peptide and six potential 
asparagine-linked glycosylation sites. The galactocerebrosidase cDNA detected an 
about 4 kb mRNA band material in human cultured skin fibroblasts. A nonsense 
mutation was found at codon 369 (GAA-->TAA) in the coding sequence of cDNA 
amplified from cultured skin fibroblast mRNA from a patient with typical Krabbe 
disease.