ABCD1 and peroxisome biogenesis disorder: Nonetheless, significant differences were detected between the ZSD and ALDP groups, with higher values observed in ZSD (e.g., median C26:0 = 4.4 vs. 1.6 mmol/L, and median C26:0/C22:0 = 0.20 vs. 0.03, in ZSD and ALDP deficiency, respectively; p value < 0.0001).