Adult onset cerebral form of X-linked adrenoleukodystrophy with dementia of frontal lobe type with new L160P mutation in ABCD1 gene

Abstract

Background: X-linked adrenoleukodystrophy is a genetically determined disorder that causes varying degrees of malfunction of the adrenal cortex and central nervous system and is characterized by abnormally high levels of very long chain fatty acid in tissues and body fluids. The gene ABCD1, responsible for X-ALD, has been mapped on chromosome Xq28. More than 500 different mutations have been reported but no correlation between genotype and phenotype has been found.

Objectives: To investigate the occurrence of known or new mutations in the ABCD1 gene in patients with clinically and biochemical proven adrenoleukodystrophy.

Patient and methods: A 37-year-old patient with history of one-year progression of personality and behavioral changes such as, fluctuation of apathy and euphoria, perseveration, bizarre affect, and general disengagement, preliminarily assessed as adrenoleukodystrophy has undergone a clinical, biochemical and genetic examination in order to confirm the diagnosis and discover a possible mutation.

Results: The clinical examination has shown signs of the severe prefrontal syndrome, and a neurological examination disclosed deliberation signs and a spastic quadruparesis predominantly on the lower extremities. MRIs showed confluent hyperintensive lesions in T2 and FLAIR images in both hemispheres with severe progression over 6 to 12 months. Clinical findings referred to adrenoleukodystrophy, consecutively performed genetic analyses showed missense mutation at the codon 479 (T>C) in exon 1 of ABCD 1 gene, predicting the substitution L160P in ALD protein. The same mutation has also been found in patient's mother.

Conclusion: We examined a patient with progressive development of early onset frontal lobe type dementia and upper motor neuron signs in which neuroimaging methods and biochemical tests refer to adrenoleukodystrophy. Genetic tests revealed a new mutation at position L160P in ALD protein.