Use

Measurement of pipecolic acid in urine is useful to differentiate peroxisomal biogenesis disorders (e.g., Zellweger syndrome) from peroxisomal single enzyme deficiencies. Elevated levels may also be observed in hyperpipecolic acidemia, alpha-aminoadipic semialdehyde dehydrogenase deficiency, hyperlysinemia types 1 and 2, and proline metabolism defects. Results should be interpreted alongside other markers of peroxisomal disorders such as plasma C22–C26 very long–chain fatty acids, phytanic acid, pristanic acid, red blood cell plasmalogens, and bile acid intermediates. Pipecolic acid is not detected in conventional organic acid screening of urine.