alpha-N-acetylgalactosaminidase deficiency, a new lysosomal storage disorder.
A new lysosomal storage disease with autosomal recessive inheritance is described in two male siblings of 5 1/2 and 4 years of age. Clinical manifestations started after 9 months of age with neurological symptoms, followed by progressive psychomotor deterioration. Urinary oligosaccharide excretion was abnormal and showed a characteristic pattern on chromatography. Enzyme assays showed a profound deficiency of lysosomal alpha-N-acetylgalactosaminidase in cultured fibroblasts, leukocytes and plasma from the patients and reduced activity in material from the parents. The deficiency was demonstrated both with an artificial substrate and a natural one, the blood group A trisaccharide. Excessive intra-lysosomal storage of alpha-N-acetylgalactosamine-containing material was demonstrated in cultured fibroblasts from the patients, using the lectin from Helix pomatia which is specific for terminal alpha-N-acetylgalactosamine residues.
van Diggelen
O P
OP
Department of Clinical Genetics, Erasmus University, Rotterdam, The Netherlands.
Schindler
D
D
Willemsen
R
R
Boer
M
M
Kleijer
W J
WJ
Huijmans
J G
JG
Blom
W
W
Galjaard
H
H
D000116:Acetylgalactosamine / Q000378:metabolism; D002478:Cells, Cultured; D002675:Child, Preschool; D002855:Chromatography, Thin Layer; D005347:Fibroblasts / Q000201:enzymology; D006596:Hexosaminidases / Q000172:deficiency*; D006651:Histocytochemistry; D006801:Humans; D037102:Lectins; D007962:Leukocytes / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology*; D008297:Male; D009844:Oligosaccharides / Q000652:urine; D048809:alpha-N-Acetylgalactosaminidase
C038095:Helix lectin; D037102:Lectins; D009844:Oligosaccharides; D006596:Hexosaminidases; C482722:NAGA protein, human; D048809:alpha-N-Acetylgalactosaminidase; D000116:Acetylgalactosamine