Isobutyrylglycine

Isobutyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism.

The analysis of acylglycines is important for the diagnosis of inherited disorders of mitochondrial fatty acid beta-oxidation. Quantitative analysis of urinary acylglycine has been used to detect inborn errors of metabolism. 

In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation.

Acyl glycines are produced through the action of glycine N-acyltransferase. Isobutyrylglycine is identified in large amount in urine of patients with isobutyryl-CoA dehydrogenase deficiency.

Isobutyryl-CoA dehydrogenase deficiency (IBD deficiency) is an inborn error of valine (an amino acid) metabolism. The symptoms, which may not develop until later in infancy or childhood, can include failure to thrive, dilated cardiomyopathy, seizures, and anemia. IBD deficiency is caused by genetic changes in the ACAD8 gene. It is inherited in an autosomal recessive manner.

Moreover, Isobutyrylglycine is found to be associated with ethylmalonic encephalopathy and propionic acidemia, which are also inborn errors of metabolism.

Ethylmalonic encephalopathy is an inherited disorder that affects several body systems, particularly the nervous system. Neurological signs and symptoms include delayed development and the loss of previously acquired skills (developmental regression), weak muscle tone (hypotonia), seizures, and abnormal movements.

Propionic acidemia is an inherited disorder in which the body is unable to process certain parts of proteins and lipids (fats) properly. It is classified as an organic acid disorder, which is a condition that leads to an abnormal buildup of particular acids known as organic acids.

Note: Isobutyrylglycine is also a biomarker for the consumption of cheese.