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Clinical features of AGAT deficiency

Arginine:glycine aminotransferase (AGAT) (GATM) deficiency is an autosomal recessive inborn error of creative synthesis. We performed an international survey among physicians known to treat patients with AGAT deficiency, to assess clinical characteristics and long-term outcomes of this ultra-rare condition. 16 patients from 8 families of 8 different ethnic backgrounds were included. 1 patient was asymptomatic […]

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GAA as therapeutic target for arginase deficiency

Hyperargininaemia is a disorder of the last step of the urea cycle. It is an autosomal recessive disease caused by deficiency of liver arginase-1 and usually presents later in childhood with progressive neurological symptoms including marked spasticity. In contrast with other urea cycle disorders, hyperammonaemia is not usually present but can be a feature. A […]

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Alcohol intake affects GAA-to-creatine synthesis

We have previously shown that decreased S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio generated in livers of alcohol-fed rats can impair the activities of many SAM-dependent methyltransferases. One such methyltransferase is guanidinoacetate methyltransferase (GAMT) that catalyzes the last step of creatine synthesis. As GAMT is the major utilizer of SAM, the purpose of the study was to examine […]

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Arginase 1 deficiency leads to altered GAA metabolism

Arginase deficiency is a rare autosomal recessive disorder resulting from a loss of the liver arginase isoform, arginase 1 (ARG1), which is the final step in the urea cycle for detoxifying ammonia. ARG1 deficiency leads to hyperargininemia, characterized by progressive neurological impairment, persistent growth retardation and infrequent episodes of hyperammonemia. Using the Cre/loxP-directed conditional gene […]

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Unchanged exercise capacity in creatine-deficient mice

Creatine is thought to be involved in the spatial and temporal buffering of ATP in energetic organs such as heart and skeletal muscle. Creatine depletion affects force generation during maximal stimulation, while reduced levels of myocardial creatine are a hallmark of the failing heart, leading to the widely held view that creatine is important at […]

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Urinary excretion of GAA in diabetic nephropathy

Urinary guanidinoacetic acid (GAA) is a sensitive marker for gentamicin nephrotoxicity in rats. This study assesses the usefulness of GAA concentrations in the diagnosis of renal tubular injury in diabetic nephropathy. Serum, urine, and renal cortex samples were obtained from rats 1, 2, and 3 weeks after streptozotocin injection (65 mg/kg body weight). Guanidinoacetic acid […]

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Creatine and GAA as diagnostic markers in CDSS

In this study, measurements of guanidinoacetate (GAA) and creatine (Cr) in urine, plasma, and cerebrospinal fluid (CSF) were performed using stable isotope dilution gas chromatography-mass spectrometry. Both compounds were analyzed in a single analysis. Reference values were established for GAA and Cr. These values were age dependent. No differences with gender were observed. Eight guanidinoacetate […]

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Improving GAMT deficiency by reducing GAA levels

Guanidinoacetate methyltransferase (GAMT) deficiency (McKusick 601240), an inborn error of creatine biosynthesis, is characterized by creatine depletion and accumulation of guanidinoacetate (GAA) in the brain. Treatment by oral creatine supplementation had no effect on the intractable seizures. Based on the possible role of GAA as an epileptogenic agent, we evaluated a dietary treatment with arginine […]

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Urinary N-AG and GAA levels in epileptic patients

We investigated potential renal functional impairment induced by chronic use of anti-epileptic drugs (AEDs) in 79 epileptic children. They were divided into five groups: valproic acid (VPA) monotherapy where the serum concentration (SC) of VPA was no less than 60 micrograms/ml (VPA [SC > or = 60]) (15 cases), VPA monotherapy where the SC VPA […]

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Impaired metabolism of GAA in chronic renal failure

Most chronic renal failure (CRF) patients show low serum concentrations of guanidinoacetic acid (GAA). In this study, the author investigated the impaired metabolism of GAA in CRF focusing on the transformation of arginine (Arg) to GAA by analyzing CRF rabbits using 14C-Arg. The CRF group which consisted of 6 CRF rabbits, was compared with 6 […]

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