Chiral liquid chromatography tandem mass spectrometry in the determination of the configuration of glyceric acid in urine of patients with D‐glyceric and L‐glyceric acidurias

Abstract

Glyceric acid is a highly polar chiral carboxylic acid that is usually not detected during routine organic acid analysis. Increased excretion is observed in two phenotypically distinct and rare inherited metabolic diseases, D-glyceric aciduria, and L-glyceric aciduria (also known as primary hyperoxaluria type 2). The determination of the exact configuration of the excreted glyceric acid is necessary for the accurate diagnosis of D-glyceric aciduria and for the differentiation between type 1 and type 2 primary hyperoxaluria. The separation of the two stereoisomers was achieved using a narrow-bore ristocetin A glycopeptide antibiotic silica gel bonded column. Triethylamine acetate at pH 4.1 with 10% methanol was used as mobile phase. The column was directly interfaced to a triple quadrupole tandem mass spectrometer and the electrospray ion source was operated in the negative ion mode. Three parent-to-daughter transitions were employed to specifically detect eluting glyceric enantiomers from essentially untreated urine samples. The two forms of glyceric acid were satisfactorily separated at 3.6 and 4.5 min. Application of the method led to the confirmation of three cases of D-glyceric aciduria from three different families. Two other cases are suspected to be L-glyceric aciduria but further confirmation is needed. The method allowed the detection of the glyceric acid stereoisomers in control urine where it was found without exception that L-glyceric was the predominate metabolite.

D-glyceric aciduria

“…There is an alternative method based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the enantiomers separation and detection of the glyceric acid stereoisomers. The method allows the detection of normal levels of D-and L-glyceric acid in urine, and it was useful for the confirmation of three cases of D-glyceric aciduria and for differentiating this disease from primary hyperoxaluria type II (Rashed et al 2002). D-glyceric acid can also be identified in urine of patients by DEAE-Sephadex (Chalmers and Watts 1972).…”

“…Patients affected by D-glyceric aciduria present progressive encephalopathy, hypotonia, psychomotor and mental retardation, microcephaly, seizures, speech delay, metabolic acidosis, and even death (Brandt et al 1974, Grandgeorge et al 1980, Duran et al 1987, Insuga et al 2010) (Wadman et al 1976, Fontaine et al 1989, Rashed et al 2002. Furthermore, two patients had traces of autistic behaviors (Duran et al 1987, Topcu et al 2002.…”

“…D-Glyceric aciduria (OMIM 220120) is an autosomal recessive disease of the catabolism pathway of the amino acid serine and, to a lesser extent, of fructose metabolism (Rashed et al 2002, Sass et al 2010). The disease is caused by a deficiency of glycerate 2-kinase (EC 2.7.1.165) activity (Guo et al 2006) and its prevalence is unknown.…”

“…Glyceric acid (2,3-dihydroxypropionic acid) is a carboxylic acid with small molecular weight and being very hard to detect during routine organic acid analysis in urine of healthy individuals (Rashed et al 2002). This compound is found in humans in two different configurations, D-and L-glycerate (Brandt et al 1974.…”

“…L-glyceric acidurias (the latter being also known as primary hyperoxaluria type II) (Rashed et al 2002). The clinical phenotype of L-glyceric aciduria predominantly involves renal alterations, including recurrent nephrolithiasis, while D-glyceric aciduria mainly affects the central nervous system (Bonham et al 1990).…”