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Urinary GAA for CCDD screening

Cerebral creatine deficiency disorders (CCDD) are inherited metabolic disorders of creatine synthesis and transport. Urine creatine metabolite panel is helpful to identify these disorders. We reviewed electronic patient charts for all patients that underwent urine creatine metabolite panel testing in the metabolic laboratory at our institution. There were 498 tests conducted on 413 patients. Clinical, […]

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GAA as a biomarker in schizophrenia

GAA (also known as glycocyamine) is a naturally occurring metabolite of glycine and direct metabolic precursor of creatine, a key component of brain energy metabolism and oxidant-antioxidant homeostasis. GAA concentrations in the brain, cerebrospinal fluid, serum, and urine are responsive to various brain conditions, including mental, behavioral and neurodevelopmental disorders. Specifically, GAA appears to be […]

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Synovial fluid GAA as a biomarker of arthritis

Because genetic and environmental factors both contribute to rheumatoid arthritis (RA), metabolomics could be a very useful tool to elucidate the pathophysiology of RA, and to predict response to treatment. This study was carried out to investigate synovial fluid (SF) metabolic perturbation in RA patients according to the degree of disease activity using gas chromatography/time-of-flight […]

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Metabolomic characterization of SSADHD

Metabolomic characterization of post-mortem tissues (frontal and parietal cortices, pons, cerebellum, hippocampus, cerebral cortex, liver and kidney) derived from a 37 y.o. male patient with succinic semialdehyde dehydrogenase deficiency (SSADHD) was performed in conjunction with four parallel series of control tissues. Amino acids, acylcarnitines, guanidino- species (guanidinoacetic acid, creatine, creatinine) and GABA-related intermediates were quantified […]

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Plasma GAA-to-homoarginine in transplant recipients

L-Arginine:glycine amidinotransferase (AGAT) is the main producer of the creatine precursor, guanidinoacetate (GAA), and L-homoarginine (hArg). We and others previously reported lower levels of circulating and urinary hArg in renal transplant recipients (RTR) compared to healthy subjects. In adults, hArg emerged as a novel risk factor for renal and cardiovascular adverse outcome. Urinary GAA was […]

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GAA and creatine associated with cardiometabolic risk

Guanidinoacetic acid (GAA) conversion to creatine is thought to be involved in cardiometabolic disturbances through its role in biological methylation and insulin secretion. We evaluated the association of serum GAA and creatine with cardiometabolic risk factors in a cohort of 151 apparently healthy adults (82 women and 69 men) aged 18-63 years. Serum levels of […]

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Cognitive deficit and brain GAA in SLC6A8 deficiency

Creatine transporter (CrT; SLC6A8) deficiency (CTD) is an X-linked disorder characterized by severe cognitive deficits, impairments in language and an absence of brain creatine (Cr). In a previous study, we generated floxed Slc6a8 (Slc6a8 flox ) mice to create ubiquitous Slc6a8 knockout (Slc6a8-/y ) mice. Slc6a8-/y mice lacked whole body Cr and exhibited cognitive deficits. […]

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GAA affects GABA-A receptor in GAMT deficiency

Deficiency of guanidinoacetate methyltransferase (GAMT) causes creatine depletion and guanidinoacetate accumulation in brain with the latter deemed to be responsible for the severe seizure disorder seen in affected patients. We studied electrical brain activity and GABAA mediated mechanisms of B6J.Cg-Gamt(tm1Isb) mice. Electrocorticographic (ECoG) monitoring of pharmacological treatments with ornithine (5 % in drinking water for […]

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MCT12 gene mutation affects GAA excretion

A heterozygous mutation (c.643C>A; p.Q215X) in the monocarboxylate transporter 12-encoding gene MCT12 (also known as SLC16A12) that mediates creatine transport was recently identified as the cause of a syndrome with juvenile cataracts, microcornea, and glucosuria in a single family. Whereas the MCT12 mutation cosegregated with the eye phenotype, poor correlation with the glucosuria phenotype did […]

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GAA marker or an active part of ARG1 deficiency

Arginase 1 (ARG1) deficiency is a rare urea cycle disorder (UCD). This hypothesis-generating study explored clinical phenotypes, metabolic profiles, molecular genetics, and treatment approaches in a cohort of children and adults with ARG1 deficiency to add to our understanding of the underlying pathophysiology. Clinical data were retrieved retrospectively from physicians using a questionnaire survey. Plasma […]

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