In vivostudies on the metabolic derangement in a patient with D‐glyceric acidaemia and hyperglycinaemia

Abstract

In a mentally retarded boy, who excreted elevated amounts of glycine, D-glyceric acid and acylglycines and whose cells exhibited diminished D-glycerate dehydrogenase and glycine cleavage activity, investigations have been undertaken aiming at characterizing the relationship between the different accumulations. This was done in vivo by trying in a specific manner to alter in turn the degree of accumulation of each of the three classes of compounds and then monitoring changes in the others. The results suggest, that the D-glyceric acid accumulation is directly caused by the genetic defect, since the D-glyceric acid excretion was not altered by changes in degree of accumulation of either glycine or acylglycines. Similarly alterations in acylglycine excretion caused alterations in glycine but not in D-glyceric acid excretion. Based on these findings a model for the pathogenesis behind the accumulations of acylglycines and glycine is proposed.

Pitfalls in the diagnosis of glycine encephalopathy (non‐ketotic hyperglycinemia)

“…Perhaps a coincidental association became accepted because this patient was the subject of eight separate publications. 47,54,[57][58][59][60][61][62] Whether this association is genuine or coincidental, glyceric aciduria can easily be excluded in cases of hyperglycinemia by analysis of urine organic acids using an appropriate extraction technique -a good practice in any case of suspected NKH.…”

Enantioanalysis of glyceric acid using enantioselective, potentiometric membrane electrodes: applications for the diagnosis of PH II and -glyceric acidemia/acidurias

“…Serum and urine samples were spiked with l-or d-glyceric acid to make the final concentrations as shown in Tables 4 and 5. Serum (1-3) and urine (4-8) samples were spiked with different aliquots of l-GA. On the other hand, serum (9)(10)(11) and urine (12)(13)(14)(15)(16) samples were spiked with aliquots of l-GA. These samples were used for the recovery of l-GA and d-GA in the real human matrices.…”

“…d-Glyceric acid is an intermediate of one of the pathways of serine degradation and of a minor pathway of fructose metabolism [11,12]. This increase of excretion was explained by deficiency of d-glycerate kinase that involved in the conversion of d-glyceric acid to d-2-phosphoglycerate [13][14][15][16][17]. d-Glyceric acidemia/acidurias is associated with delayed psychomotor growth, mental retardation and seizures [11,12,14,18].…”