ALDH7A1 deficiency is an epileptic encephalopathy whose seizures respond to treatment with supraphysiological doses of pyridoxine. It arises as a result of damaging variants in ALDH7A1, a gene in the lysine catabolism pathway. α-Aminoadipic semialdehyde (α-AASA) and Δ1-piperideine-6-carboxylate (P6C), which accumulate because of the block in the lysine pathway, are diagnostic biomarkers for this disorder. Recently, it has been reported that 6-oxo-pipecolic acid (6-oxo-PIP) also accumulates in the urine, CSF and plasma of ALDH7A1-deficient individuals and that, given its improved stability, it may be a more suitable biomarker for this disorder. This study measured 6-oxo-PIP in urine from a cohort of 30 patients where α-AASA was elevated and showed that it was above the normal range in all those above 6 months of age. However, 6-oxo-PIP levels were within the normal range in 33% of the patients below 6 months of age. Levels increased with age and correlated with a decrease in α-AASA levels. Longitudinal analysis of urine samples from ALDH7A1-deficient patients who were on a lysine restricted diet whilst receiving supraphysiological doses of pyridoxine showed that levels of 6-oxo-PIP remained elevated whilst α-AASA decreased. Similar to α-AASA, we found that elevated urinary excretion of 6-oxo-PIP can also occur in individuals with molybdenum cofactor deficiency. This study demonstrates that urinary 6-oxo-PIP may not be a suitable biomarker for ALDH7A1 deficiency in neonates. However, further studies are needed to understand the biochemistry leading to its accumulation and its potential long-term side effects.

• Klíčová slova
• 6‐oxo‐pipecolic acid, ALDH7A1 deficiency, aminoadipic semialdehyde, piperideine‐6‐carboxylate, pyridoxine‐dependent epilepsy,
• MeSH
• aldehyddehydrogenasa nedostatek   genetika   MeSH
• biologické markery * moč   MeSH
• dítě MeSH
• epilepsie moč   MeSH
• kojenec MeSH
• kyselina 2-aminoadipová moč   analogy a deriváty   MeSH
• kyseliny pipekolové * moč   MeSH
• lidé MeSH
• lysin nedostatek   moč   MeSH
• mitochondriální aldehyddehydrogenasa nedostatek   genetika   MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• pyridoxin nedostatek   moč   terapeutické užití   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• aldehyddehydrogenasa MeSH
• ALDH7A1 protein, human MeSH Prohlížeč
• biologické markery * MeSH
• kyselina 2-aminoadipová MeSH
• kyseliny pipekolové * MeSH
• lysin MeSH
• mitochondriální aldehyddehydrogenasa MeSH
• pipecolic acid MeSH Prohlížeč
• pyridoxin MeSH