Adrenoleukodystrophy an Overview

Abstract

Adrenoleukodystrophy (ALD) is a rare X-linked peroxisomal oxidation disease caused by mutations in ABCD1. It presents with various clinical manifestations, including cerebral ALD, myelopathy, and primary adrenal insufficiency. About 80% of ALD patients suffer from adrenal insufficiency, and cerebral ALD affects one-third of boys under twelve, progressing to total impairment and death without treatment. Hematopoietic stem cell transplantation (HSCT) is the only disease-modifying treatment for early-stage cerebral ALD, but it does not halt adrenal insufficiency progression and carries significant morbidity and mortality risks. A recent gene therapy clinical trial showed short-term MRI and neurological outcomes equivalent to past HSCT treatments without the adverse side effects. Additionally, over a dozen states have initiated newborn screening (NBS) for ALD, with the number expected to triple by 2020. Genetic testing of NBS-positive newborns has identified novel variations of unknown significance, raising questions about monitoring and treating preclinical or moderate adrenal insufficiency or cerebral involvement. This presents further opportunities for genetic characterization. The availability of matching donors, transplant centers, and specialists will impact prompt treatment for those diagnosed with ALD at birth. As NBS and gene therapy trials improve ALD's clinical management and prognosis, endocrine management of presymptomatic and subclinical adrenal insufficiency will become increasingly important.