Biochemical contribution to diagnosis and study of a new case of D-glyceric acidemia/aciduria.
During organic acid screening by gas chromatography/mass spectrometry, we detected a large peak corresponding to glyceric acid in a patient's urine sample. The D(+) configuration was demonstrated by a polarimetric method and by enzymatic stereospecificity of D-glycerate dehydrogenase (EC 1.1.1.29). We biochemically investigated this fifth reported case of D-glyceric acidemia. In our patient, loading tests with L-serine and fructose led to an increase of D-glyceric acid in both plasma and urine. Determination of other metabolites involved in D-glycerate metabolism revealed no abnormality in any sample examined. After comparing all our results with those of the preceding observations described in the literature, we suggest a possible enzymatic defect located on one of the metabolic pathways shared by fructose and L-serine, possibly at the level of hepatic D-glycerate kinase (EC 2.7.1.31). Nevertheless, a primary defect of L-serine catabolism cannot be entirely excluded.
Fontaine
M
M
Laboratoire de Biochimie, Hôpital Huriez, Centre Hospitalier, Régional et Universitaire, Lille, France.
Porchet
N
N
Largilliere
C
C
Marrakchi
S
S
Lhermitte
M
M
Aubert
J P
JP
Degand
P
P
D055598:Chemical Phenomena; D002621:Chemistry; D005260:Female; D005632:Fructose; D008401:Gas Chromatography-Mass Spectrometry; D005988:Glyceric Acids / Q000378:metabolism / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D007223:Infant; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000652:urine; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D012694:Serine
D005988:Glyceric Acids; D007202:Indicators and Reagents; D005632:Fructose; D012694:Serine; C042971:glyceric acid; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020670:glycerate kinase