In-frame deletion variant of ABCD1 in a sporadic case of adrenoleukodystrophy

Adrenoleukodystrophy (ALD), an X-linked leukodystrophy caused by pathogenic variants in ABCD1, exhibits a broad range of phenotypes from childhood-onset cerebral forms to adult-onset adrenomyeloneuropathy (AMN). We report a rare in-frame ABCD1 deletion c.1469_71delTGG (p.Val490del) in a man with AMN. Although this variant has been interpreted as 'uncertain significance' in ClinVar, biochemical analysis along with clinical evaluation confirmed the pathogenicity of this variant, underscoring the importance of functional assessment of in-frame deletions.