X-linked adrenoleukodystrophy in a chimpanzee due to an ABCD1 mutation reported in multiple unrelated humans

Abstract

Background X-linked adrenoleukodystrophy (X-ALD) is a genetic disorder leading to the accumulation of very long chain fatty acids (VLCFA) due to a mutation in the ABCD1 gene. ABCD1 mutations lead to a variety of phenotypes, including cerebral X-ALD and adrenomyeloneuropathy (AMN) in affected males and 80% of carrier females. There is no definite genotype-phenotype correlation with intrafamilial variability. Cerebral X-ALD typically presents in childhood, but can also present in juveniles and adults. The most affected tissues are the white matter of the brain and adrenal cortex. MRI demonstrates a characteristic imaging appearance in cerebral X-ALD that is used as a diagnostic tool. Objectives We aim to correlate a mutation in the ABCD1 gene in a chimpanzee to the human disease X-ALD based on MRI features, neurologic symptoms, and plasma levels of VLCFA. Methods Diagnosis of X-ALD made using MRI, blood lipid profiling, and DNA sequencing. Results An 11-year-old chimpanzee showed remarkably similar features to juvenile onset cerebral X-ALD in humans including demyelination of frontal lobes and corpus callosum on MRI, elevated plasma levels of C24:0 and C26:0, and identification of the c.1661G>A ABCD1 variant. Conclusions This case study presents the first reported case of a leukodystrophy in a great ape, and underscores the fidelity of MRI pattern recognition in this disorder across species.