Hyperoxaluria

Glycinuria results from a defect in renal tubular reabsorption. The defect in primary hyperoxaluria is the failure to catabolize glyoxylate formed by deamination of glycine. Subsequent oxidation of glyoxylate to oxalate results in urohthiasis, nephrocalcinosis, and early mortality from renal failure or hypertension. 

Metabohc diseases associated with glycine catabohsm include glycinuria and primary hyperoxaluria. 

Hyperoxaluria type 1 is due to functional efficiency of the liver specific peroxisomal enzyme alanine-glyoxylate aminotransferase. It leads to severe renal failure. The nervous system is not affected. 

Urinary oxalate Some patients may develop increased levels of urinary oxalate following treatment. Exercise caution in patients with a history of hyperoxaluria or calcium oxalate nephrolithiasis. 

Contraindications Primary or secondary hyperparathyroidism, including hypercalci-uria (renal calcium leak), hypomagnesemic states (serum magnesium less than 1.5 mg/dl), bone disease (osteoporosis, osteomalacia, osteitis), hypocalcemic states (e.g., hypoparathyroidism, intestinal malabsorption), normal or low intestinal absorption and renal excretion of calcium, enteric hyperoxaluria, and patients with high fasting urinary calcium or hypophosphatemia. 

Hyperoxaluria and hypomagnesiuria, which negate the beneficial effect of hypo-calciuria on new stone formation, magnesium depletion, and depletion of trace metals (copper, zinc, iron) may occur. 

Unlabeled Uses Treatment of diarrhea (due to bile acids), hyperoxaluria... 

D-bifunctional protein deficiency [5], 2-methyl acyl-CoA racemase (AMACR) deficiency [3] and sterol carrier protein (SCP-x) deficiency [6], the disorders of etherphospholipid biosynthesis (dihydroxyacetone phosphate acyltransferase and alkyl- dihydroxyacetone phosphate synthase deficiency) [2], the disorders of phytanic acid alpha-oxidation (Refsum disease) [15], and the disorders of glyoxylate detoxification with hyperoxaluria type 1 as caused by alanine glyoxylate aminotransferase deficiency as a sole representative. 

Table 3.5.4 Laboratory findings for patients with primary hyperoxaluria type I (modified from Schnakenburg and Latta [1]). N Normal, P plasma, U urine...

Fig. 3.5.4a-c Chromatographic separation of glycolate, chloride, sulfate, oxalate, phosphate, and citrate, a Standard mixture b nondiseased urine C urine from a patient with primary hyperoxaluria type I. In this system, glycolate coelutes with fluoride... 

Von Schnakenburg C, Latta (2005) Hyperoxaluria. In Blau N, Duran M, Blaskovics M, Gibson KM (eds) Physician s Guide to the Laboratory Diagnosis of Metabolic Disease, 2nd edn. Springer, Heidelberg, pp 509-518... 

Leumann E, Hoppe B, Neuhaus T, Blau N (1995) Efficacy of oral citrate administration in primary hyperoxaluria. Nephrol Dial Transplant 10 14-16... 

This is apparently an indirect result of the primary defect in utilization of hydroxypyruvate. It has been suggested that oxidation of glyoxylate by NAD+ is coupled to the reduction of hydroxypyruvate by NADH 366 This and other hyperoxalurias are very serious diseases characterized by the formation of calcium oxalate crystals in tissues and often death from kidney failure before the age of 20. 

Located in the peroxisomes of liver, L-alanine-glyoxylate aminotransferase catalyzes the transamination of alanine and glyoxylate to form pyruvate and glycine. A rare inborn error of metabolism manifested as hyperoxaluria is due to a deficiency of this enzyme. 

Primary hyperoxaluria, type 1 Peroxisomal alanine-glyoxylate transaminase 2.6.1.44... 

As shown in Table 9.4, vitamin Be dependency has been reported in cases of type I primary hyperoxaluria, xanthurenic aciduria, homocystinuria, hypochromic sideroblastic anemia, gyrate atrophy with ornithinemia, and vitamin Be responsive infantile convulsions. In this last condition, the underlying defect has not been identified, but is almost certainly not impaired activity of glutamate decarboxylase. 

Glycollic aciduria (Primary hyperoxaluria Type I) Glycollic, glyoxylic, oxalic... 

Calcareous stones result from hypercalciuria, hyperoxaluria and hypocitraturia. Hypercalciuria and hyperoxaluria render urine supersaturated in respect of calcium salts citrate makes calcium oxalate more soluble and inhibits its precipitation from solution. 

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