Abcd2, also known as the adrenoleukodystrophy-related gene, is a potential therapeutic target for X-linked adrenoleukodystrophy. Mutations in the ABCD1 gene cause this rare neurodegenerative disease, and up-regulation of ABCD2 expression can compensate for ABCD1 deficiency, restoring peroxisomal β-oxidation of very-long-chain fatty acids [4].

No relevant findings from KO/CKO mouse models or loss-of-function experiments are provided in the given references. However, in the context of clinical decision-making, the ABCD2 score (derived from age, blood pressure, clinical features, duration of symptoms, diabetes) is used to screen for stroke risk. But it has limitations. For example, in patients with acute vestibular syndrome, HINTS examination outperforms ABCD2 score in stroke diagnosis [1,3,5]. Also, the ABCD2 score does not reliably discriminate those at low and high risk of early recurrent stroke, nor identify patients with carotid stenosis or atrial fibrillation needing urgent intervention [2].

In conclusion, Abcd2 is crucial in the context of X-linked adrenoleukodystrophy as its up-regulation can compensate for ABCD1 deficiency. In clinical practice, while the ABCD2 score is used for stroke risk assessment, its limitations suggest the need for better methods. The study of Abcd2 not only helps in understanding the pathophysiology of X-linked adrenoleukodystrophy but also in improving stroke risk prediction and patient management [1,2,3,4,5].

References:

1. Newman-Toker, David E, Kerber, Kevin A, Hsieh, Yu-Hsiang, Zee, David S, Kattah, Jorge C. . HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. In Academic emergency medicine : official journal of the Society for Academic Emergency Medicine, 20, 986-96. doi:10.1111/acem.12223. https://pubmed.ncbi.nlm.nih.gov/24127701/

2. Wardlaw, Joanna M, Brazzelli, Miriam, Chappell, Francesca M, Sandercock, Peter A G, Dennis, Martin S. 2015. ABCD2 score and secondary stroke prevention: meta-analysis and effect per 1,000 patients triaged. In Neurology, 85, 373-80. doi:10.1212/WNL.0000000000001780. https://pubmed.ncbi.nlm.nih.gov/26136519/

3. Gerlier, Camille, Hoarau, Maëlle, Fels, Audrey, Chatellier, Gilles, Ganansia, Olivier. 2021. Differentiating central from peripheral causes of acute vertigo in an emergency setting with the HINTS, STANDING, and ABCD2 tests: A diagnostic cohort study. In Academic emergency medicine : official journal of the Society for Academic Emergency Medicine, 28, 1368-1378. doi:10.1111/acem.14337. https://pubmed.ncbi.nlm.nih.gov/34245635/

4. Trompier, Doriane, Gondcaille, Catherine, Lizard, Gérard, Savary, Stéphane. 2014. Regulation of the adrenoleukodystrophy-related gene (ABCD2): focus on oxysterols and LXR antagonists. In Biochemical and biophysical research communications, 446, 651-5. doi:10.1016/j.bbrc.2014.01.025. https://pubmed.ncbi.nlm.nih.gov/24480443/

5. Tarnutzer, Alexander A, Edlow, Jonathan A. 2023. Bedside Testing in Acute Vestibular Syndrome-Evaluating HINTS Plus and Beyond-A Critical Review. In Audiology research, 13, 670-685. doi:10.3390/audiolres13050059. https://pubmed.ncbi.nlm.nih.gov/37736940/