Referring to international recommendations for the diagnosis and management of patients with X-ALD, in vitro fibroblast studies [22] were conducted to study the pathogenicity of a VUS in ABCD1 and were especially recommended in asymptomatic boys and men with biomarker levels above the upper reference range of controls, but below the disease range (of the diagnostic laboratory) [3]. This evidence concerns the gene ABCD1 and X-linked adrenoleukodystrophy.