Klasyczne i nowe biomarkery w epilepsji zależnej od pirydoksyny (PDE-ALDH7A1): znaczenie dla wczesnej diagnozy i rozwoju leczenia
Classical and Emerging Biomarkers in Pyridoxine-Dependent Epilepsy (PDE-ALDH7A1): Implications for Early Diagnosis and Therapeutic Development
W skrócie
Epilepsja zależna od pirydoksyny to rzadka, ale możliwa do leczenia choroba neurologiczna spowodowana brakiem enzymu ALDH7A1, który prowadzi do gromadzenia się szkodliwych substancji w organizmie i utraty witaminy B6. Chociaż dodatek pirydoksyny (witaminy B6) zwykle zatrzymuje napady, wiele dzieci nadal ma problemy z rozwojem mózgu, dlatego wczesne rozpoznanie jest bardzo ważne. Naukowcy znaleźli nowe, bardziej stabilne markery choroby, które mogą ułatwić wczesne wykrycie i lepsze zrozumienie mechanizmów choroby, co pozwoli na opracowanie skuteczniejszych leków.
Oryginalny abstract (angielski)
Pyridoxine-dependent epilepsy due to ALDH7A1 deficiency (PDE-ALDH7A1) is a rare but treatable epileptic encephalopathy caused by disruption of lysine catabolism and secondary depletion of pyridoxal-5'-phosphate (PLP). Although seizures are often controlled with pyridoxine supplementation, many patients continue to experience neurodevelopmental impairment, underscoring the importance of early diagnosis and improved therapeutic strategies. Central to both diagnosis and pathophysiology is the accumulation of lysine-derived metabolites, most notably α-aminoadipate semialdehyde (α-AASA), its cyclic Schiff base Δ-piperideine-6-carboxylate (P6C), and pipecolic acid. These metabolites have become the biochemical hallmarks of PDE-ALDH7A1, linking pathogenic variants to PLP inactivation and neuronal dysfunction. However, their chemical instability and analytical requirements pose challenges for universal diagnostics and newborn screening. This review summarizes current understanding of lysine catabolism in health and disease, critically evaluates the diagnostic utility and limitations of classical biomarkers, and discusses emerging insights into their pathophysiological roles. We further highlight recent discoveries of novel, chemically stable biomarkers, including 6-oxopiperidine-2-carboxylic acid (6-oxo-PIP), 2-oxopropylpiperidine-2-carboxylic acid (2-OPP), and 6-hydroxy-2-aminocaproic acid (HACA), identified through advanced metabolomics approaches. These metabolites show promise for newborn screening and provide new mechanistic links between metabolic stress, seizure susceptibility, and ongoing neurological morbidity despite pyridoxine treatment. Collectively, advances in biomarker discovery are reshaping diagnostic strategies for PDE-ALDH7A1 and offering new perspectives on disease mechanisms, paving the way for earlier detection and the development of more effective, mechanism-based therapies.