The phenotype expression in X-linked adrenoleukodystrophy is one of the most intriguing issues of the disease, because there is no general correlation between the type of ABCD1 gene mutation and the clinical phenotype. In this study, we use the cross-impact analysis to build a descriptively quantitative relationship between mutant adrenoleukodystrophy protein and classification of adrenoleukodystrophy with the amino-acid distribution probability, which is a quantitative measure sensitive to mutation. Then we determine the probability that the adrenoleukodystrophy can be classified under mutations with the help of a Bayesian equation.