TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Sjarif, Damayanti R.
A1  - Hellerud, Christina
A1  - van Amstel, Johannes K. Ploos
A1  - Kleijer, Willem J.
A1  - Sperl, Wolfgang
A1  - Lacombe, Didier
A1  - Sass, Jörn Oliver
A1  - Beemer, Frits A.
A1  - Duran, Marinus
A1  - Poll-The, Bwee Tien
T1  - Glycerol kinase deficiency: residual activity explained by reduced transcription and enzyme conformation
JF  - Eur J Hum Genet. (European Journal of Human Genetics)
N2  - Four unrelated patients with glyceroluria ranging from 7 to 170 mmol/l were studied. The activity of glycerol kinase (GK) in cultured fibroblasts was determined with a specific enzyme assay and with two indirect methods, that is, incorporation into macromolecules of [(14)C] from [(14)C]glycerol and its oxidation to [(14)C]CO(2). Exon amplification and RT-PCR were used to identify mutations. In patient 1, with low activity in all three assays, we identified a c.1194A>C (E398D) missense mutation. In patient 2 with a considerable activity of the GK enzyme (22% of reference), oxidation to [(14)C]CO(2) (37%) and a high incorporation of [(14)C] into macromolecules (92%), we identified a c.182T>C (L61P) mutation that causes the enzyme to have a higher K(m) for glycerol ( approximately 300 microM) than normals (2-8 microM). In patient 3, the GK activity estimated by the three different methods ranged from 16 to 22% of reference. Analysis of mRNA from the GK gene revealed three alternatively spliced transcripts. A mutation in intron 3 (g.16835G>A) resulted in an insertion of a cryptic exon between exon 2 or 3 and exon 4. Patient 4 with minor glyceroluria (7 mmol/l) and normal plasma glycerol concentration had normal activity with all three assay methods, thus excluding GK deficiency (GKD) as a cause of slight glyceroluria. To evaluate fully patients with glyceroluria, one needs to measure the GK activity and relate this and the clinical data to genetic findings. Residual enzyme activities in cultured fibroblasts can be found in GKD patients with severe clinical symptoms.
Y1  - 2004
SN  - 1018-4813
SS  - 1018-4813
U6  - https://doi.org/10.1038/sj.ejhg.5201172
DO  - https://doi.org/10.1038/sj.ejhg.5201172
PM  - 15026783
VL  - 12
IS  - 6
SP  - 424
EP  - 432
PB  - Nature Publishing Group
ER  -