X-LINKED adrenoleukodystrophy (ALD)1,2 is a disorder with widely varying phenotypes. These range from the rapidly progressive childhood cerebral form, which often leads to severe disability and death by age 10 years, to the slowly progressive adrenomyeloneuropathy, which manifests most commonly between ages 20 and 30 years and may be compatible with survival to the eighth and even ninth decade. It may also present as primary adrenocortical insufficiency without demonstrable nervous system involvement. All phenotypes co-occur frequently within the same nuclear family. The milder adult phenotype is often misdiagnosed as multiple sclerosis or as a spastic paraparesis of unknown cause. It is now recognized that these milder adult variants are as common or even more common than the severe childhood form.
Moser HW, Kemp S, Smith KD. Mutational Analysis and the Pathogenesis of Variant X-linked Adrenoleukodystrophy Phenotypes. Arch Neurol. 1999;56(3):273-275. doi:10.1001/archneur.56.3.273