GM2-gangliosidosis. Clinical and biochemical aspects of four cases.
We discuss four cases of GM2-gangliosidosis. In one of them the biochemical diagnostic confirmation was difficult. This case revealed striking discrepancies between the results of different methods of enzyme assay. The hexosaminidase A determination based on pH inactivation is not always reliable; assay with natural substrate may be necessary. However, the results with the newly developed substrate 4-MU-GlcNac-6-SO4 are promising and it seems to be a good alternative to the traditional (pH or heat) inactivation procedures. The deficiency can be shown in leukocytes, plasma and fibroblasts with the 6-sulfated substrate. The carrier state seems better reflected in plasma hexosaminidase A than in leukocyte hexaminidase A levels.
Praamstra
P
P
Institute of Neurology, University Hospital Nijmegen, The Netherlands.
Wevers
R A
RA
Gabreëls
F J
FJ
Rotteveel
J J
JJ
Renier
W O
WO
Sengers
R C
RC
Lamers
K J
KJ
D000328:Adult; D005260:Female; D054818:Hexosaminidase A; D006801:Humans; D007223:Infant; D008297:Male; D012497:Sandhoff Disease / Q000175:diagnosis* / Q000201:enzymology / Q000503:physiopathology; D013661:Tay-Sachs Disease / Q000175:diagnosis* / Q000201:enzymology / Q000503:physiopathology; D001619:beta-N-Acetylhexosaminidases / Q000172:deficiency*
D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases